OrangeTractorTalks

A Kubota L1-R24 in its rearward operating configuration.

We recently received a comment from Ian King, an OrangeTractorTalks reader from British Columbia, Canada (map), asking for some information on his recently acquired Kubota L1-R26 tractor. Unable to find much, if any information on it, Mr. K and I decided to answer some of Ian’s questions with a feature story on his unique Kubota!

The L1-R Family Tree
In North America, an L1-R Kubota is extremely rare and seldom seen – built exclusively for the Japanese Domestic Market (JDM) between 1983-1988. Since it was a JDM tractor only, Kubota North America brands the L1-R series as gray market tractors. The L1-R series tractors consist of the L1-R20, L1-R22, L1-R24, L1-R26 and L1R-28 – all of which are a marvel of Kubota design engineering. Ian’s bidirectional Kubota is from the L1 Series of Kubotas that include these models:

• Early L1 Series
  L1-20, L1-22, L1-24, L1-26, L1-28, L1-33, L1-38, L1-43, L1-45

• Later L1-5 Series
  L1-185, L1-195, L1-205, L1-215, L1-225, L1-235, L1-245, L1-255, L1-265, L1-275, L1-285, L1-295, L1-315, L1-325, L1-345, L1-385, L1-435, L-455

Ian's Kubota L1-R26 in the forward configuration with a front end loader ready to do some work.

The R designation in the model number means the tractor can be driven and operated in either the traditional forward facing manner, or with a few quick adjustments they can be safely operated and driven with the driver facing backwards. Finding a use for a backwards running tractor may seem a little odd at first, but, they are more common than you may think. In fact, Kubota is not the first manufacturer to develop and build a bidirectional tractor…

Bidirectional Tractor History
You have to hand it to the average hard working farmer – masters of ingenuity, dreamers and developers, they have come up with some of the most creative ways to get things done, make things work, or repurpose old machinery for a new task. It is this line of thinking that gave birth to the bidirectional tractor.

In the late 1960s, a couple of talented brothers, Peter and Dan Pakosh from Manitoba, Canada (map), were building grain augers, drawbars and field sprayers under their own brand name, Versatile. Credited with being the first company to mass produce 4WD farm tractors, brother Dan thought that a market existed for a multipurpose tractor that could be operated bidirectionally. Surely the world was ready for such an innovation!

The D100, the world's first mass-produced 4WD farm tractor. Produced by Versatile in 1965.

Since the tractor could be used to either push or pull an implement, it was marketed as being “a number of self-propelled machines in one”. The concept was an immediate success. With 4WD and a switchable operator’s platform, bidirectional tractors had arrived! 20 years later, when was Versatile sold to Ford-New Holland, the design engineers at New Holland brought Dan Pakosh out of retirement to help them modernize the bidirectional tractor, taking it forward into the next century. The result was the New Holland TV-140.

The Ford-New Holland TV-140 - a result of redesigning and bringing the bidirectional tractor into the 20th century.

Simplified Timeline

• Late 1930s – Early 1940s
  Peter Pakosh goes to work for Massey Harris honing his skills as a designer, draftsman and inventor.

• 1960s
  Peter and his brother Dan become the first to mass produce a 4WD farm tractor, the Versatile D100.

• 1977
  Versatile brings the world’s first bidirectional tractor to market – the
  Versatile Model 150.

• 1982
  Versatile iterates on their design and introduces the Model 160

• 1987
  New Holland buys Versatile and starts developing the next generational of bidirectional tractors – the New Holland TV 140.

• 1983-1988
  Kubota brings out their own line of bidirectional tractors, the L1-R Series.

Service Department Vic standing beside a Versatile 160 bidirectional tractor. Versatile built the 160 from 1982-1983.

Engines, Drivelines, Nuts and Bolts
Ian’s L1-R26 is equipped with a Kubota V1512 direct injected 4 cylinder engine. The V1512 was used in a number of JDM Kubota tractor models including the L1-265, L1-285, L1-295, L1-315 and was also used in the L1-R28. Depending on injector pump pressure and timing, the V1512 was rated anywhere from 26-32 horsepower at the PTO.

Transmissions and final drives are shared on Ian’s Kubota with the Kubota L2250, L2550, L2650 and L2950. While these North American models had 4 ranges and 4 working speeds to the transmission (16F), the JDM versions offered 20F speeds. Both the Japanese Domestic Market and North American models feature a mechanical shuttle shift.

PTO Speeds
All L1-R’s have 4 speed PTOs which operate at these speeds (@ 2500 engine RPM): 566 RPM, 774 RPM, 938 RPM and 1250 RPM. Interestingly, all L and L-1 gray models have 4 speed PTOs and gray market B series have 3 speed PTOs. For North American models (non gray market equipment), Kubota limited the PTO to only 2 speeds.

Going From Front to Back and Back Again
An owner of a L1-R series needs to a few things if they wish to switch from front operation to rear-facing operation:

1. The steering column is detached from its location by unscrewing a set bolt located adjacent to the PTO speed change lever.



Steering wheel release located next to the PTO speed lever.

2. The dash blank out panel is unclipped and stowed.



When switching to the reverse configuration, this blank out panel is removed and the seat is installed in its place.

3. The seat is released and mounted where the dash blank out panel was removed. Note that because of the placement of the speed change lever and shuttle shift, control of the tractor is still natural feeling in either forward or reverse configurations.



A close up of the L1-R shuttle shift - its placement means operating the tractor is not awkward regardless of forward or reverse configuration.

4. When operated in the reverse position, the driver’s feet would rest on foot pads, one located on the right hand side of the seat by the position control, and the other rubber foot pad on the center of the transmission tunnel where the transmission is filled.



Driver's feet rest on foot pads that are normally under the seat.

5. The brake and clutch pedal pads are connected with bolts on Kubota’s Reversing L-1 tractors, rather than welded on as they are on the L1-18, 20 etc. For reward operation, these pads are removed and are installed on redundant pedal “posts” that are located on either side of the operator’s seat. A complete set of duplicate pedals – gas, brake and clutch are sitting under the seat!



Redundant gas, brake and clutch pedals are located under the seat (shown here tipped forward). Photo credit: OrangeTractorTalks reader Keith

6. The steering column is reinstalled where the seat used to be.

7. The final detail would be to swap the tires from side to side in order to maximize the traction of the R-1 Ag Grips.

An L1-R24 before and after swapping from forward to reverse operation.

Cab Versions
Cab versions of L1-R Series Kubotas were equipped with front and rear windshield wipers, and in addition to having lots of glass, the cab versions had a glass window that was at the back of the tractor behind the seat.

An L1-R Kubota equipped with a cab - note the rear glass panel for viewing ground near the PTO and the rear wiper.

Non-cab versions had a plexiglass panel just behind the seat which incidentally, had two armrests rather than a single armrest seat version installed on non-Reverse models. This opening made viewing the ground right at the 3 point hitch possible when operating in the rearward facing position.

What were these Tractors Used For?
Since these tractors provided a very detailed view of the goings on at the PTO end of the tractor, the L1-R Series of Kubota was used in much the same way as its Versatile and New Holland ancestors were:

• precision seeding
• planting and tilling
• bidirectional mowing
• PTO operation of a rotary brush or broom
• snow blowing
• lifting pallets
• trenching
• hoe operation
• bulldozing

Anywhere that increased maneuverability and tight handling were needed, the L1-R Kubotas were pressed into use! You can see from this video a L1-R Kubota in action (thanks to OrangeTractorTalks reader Dan Alex for finding it).

There you have it, a history and overview of a rare and unique Kubota. If you have more detailed questions or comments regarding the L1-R series, ask away in the comments below and we’ll do our best to answer.

Service Department Vic

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Why Chains?
If you are operating your Kubota compact tractor equipped with turf tires and you would like to get the most utility from your equipment, then that means being able to use your Kubota year round. The problem is, turf tires are good for the lawn in July but are not as handy on the driveway in January! Chaining up the turf tires is an excellent way to get the traction assist you need without the expense and effort of buying another set of rims and tires.

Tire chains installed on the turf tires of this B6200 boost traction enough for us to use a snow blade to clear the driveway.

Types of Tire Chains
One would think that not much that could be new with a tire chain – it is just a few links of metal crisscrossed over the tire, right? In fact, there are a few different versions of tire chains available for your Kubota tractor, each with some unique characteristics that are worth taking a look at:

• ladder style
• double cross
• duo ladder

Ladder Style Chains
The most common style of tractor tire chain is the ladder style. Uninstalled, these chains look like a ladder when laid out. Most ladder style chains have “rungs” that cross every fourth link in the side chains. These cross rungs sit on the tread face and ultimately make contact with the ground.

Ladder style chains have cross rungs every 4th link on the side lengths. For our B6200 this means 13 cross lengths for each wheel.

Double Cross Chains
A common variation on the 4-link ladder above, is the double cross where a cross length is attached every second link on the side chains. This means there are twice as many cross rungs in contact with the ground providing for superb traction and minimal tire wear.

Double cross chains are just that - twice as many cross-ways lengths in contact with the ground.

Duo Ladder Chains
Another variation of the ladder style tire chain is the duo ladder. This version utilizes case hardened cross lengths attached every second and fourth side link on the perimeter chain and further attached every second and third cross length. Duo ladder chains are recommended for AG Grip or R4 industrial tires used off road, so no pavement or concrete driveway clearing when equipped with these type of chains.

Duo ladder chains, typically not used on hard surfaces such as pavement or concrete.

Installation Guide
Without a doubt, the easiest way to install tire chains on your Kubota is with the help of a good floor jack. While not absolutely necessary, a jack does allow you to lift one tire at a time which really helps. Here is a quick low down on tire chain installation assuming you have access to a floor jack.

1. Park your Kubota on a level firm surface like the garage or shop floor, check tire pressures and adjust as required.
2. Turn off the engine, remove the ignition key.
3. Place a wheel chock or block in front of both front tires.
4. From the rear of the tractor, place the floor jack under the left hand rear axle close to the left hand rim.
5. Operate the jack to raise the left hand rear rim and tire only a couple of inches off the ground.
6. Do not attempt to lift the entire back end of the tractor by jacking it up in the middle of the rear axle – attempting to balance the tractor on the jack!
7. Take one tire chain, lay it out flat on the garage or shop floor, and untangle it if necessary. Pay attention to the curled ends (A) of the cross chains.
   

   Cross lengths that are finished with curled ends - you will want to make sure these face down when the chain is laid out on the floor.

8. You’ll want to make sure that the curled ends face down when the chain is sitting on the floor.
9. Pick the chain up and drape it over the tire orientating in such a way that the curled ends of the cross chains will curl up and away from the crown of the tire when the chain is installed.


Correctly draped chains will have the curled ends curving up and away from the crown of the tire as shown here.

10. Depending on your make and brand of chains, there may be a lever fastener or a snap clip fastener that joins the two sides of the chain together. Make sure that the lever or snap clip is on the outside of the tire.


Your chains may be equipped with snap fasteners that join the two ends of the chain together as shown here.

11. Adjust the chain for straightness, centering the chain on the tread face equally.
12. Place the first cross chain (opposite the end with fastener and inside hook) under the tire.
13. Pull the inside rim chain tight and hook the inside hook. Pull the outside rim chain tight and hook the outside lever fastener (B) by running the end through a free link (C).


Pull the inside chain, closest to the rim, tight and hook the inside hook.

14. Close the fastener by rotating it back 180 degrees and engaging the hook (D) on the end of the fastener into a rim chain link (E). Make sure the chain is centered on the tire with approximately the same number of free rim links (F) on the inside and outside.


Close the fastener by rotating it back 180 degrees.

15. Tie back any excess rim chain links (G) back to the rim chain.


Tie back excess chain links.

16. Try to get the chains as tight as possible, readjust the lever fasteners if necessary.
17. Slowly lower the jack, reposition to the other side of the tractor and repeat installation process on right hand side tire.
18. Once installed, remove the jack and parking block or chock, and operate the tractor for a few hundred feet, forward and then backward, to seat the chains. Check to ensure tightness, and readjust as necessary. Periodically over the winter season, check air pressure and chains, adjusting pressure and fit as necessary.

Taking Up Slack
You may feel it is necessary to add a few rubber bungee cords to take up any slack on the chains. Just make sure that you take the slack to the outside of the wheel and tire, not the inside. Excess chain and bungee cords may become tangled up on the axle or axle stubs if placed on the inside.

Cost of Tire Chains
A decent set of chains for you Kubota will cost anywhere from $150-275 depending on the style of chain you select and of course tire size. If your Kubota is a 4×4 it is not a bad idea to chain up the front tires as well. If you decide to just do the rears and you experience some under steer, separate the brake pedals and use them individually to brake steer your Kubota when pushing down a long stretch. This tip works real well when you have the bucket angled down slightly and all ready have the front tires of the tractor a little high.

Service Dept Vic

Related Articles
How to Clear Snow with a Snow Blade
How to Use your Kubota’s Differential Lock

Your Kubota’s snow blade – an implement that is earning its keep this winter! Record snow falls all across North America has meant a lot of seat time for Kubota tractor owners as they push, pile, blade and bucket their way through winter! Even if your Kubota tractor is equipped with a front end loader, there are still a lot of reasons to have this handy, often under rated, implement.

A typical snow blade that has seen some use. This one, manufactured by Farm King, is in back blade position and attached to a Kubota B6200.

General Blading Technique
The general steps to clearing your driveway with a snow blade would be:

1. adjust the discharge angle by pulling the clevis pin at the top of the blade and rotating the blade – we typically have it somewhere in the middle
2. lengthen or shorten your top link to change your blade’s tilt with the ground (its aggressiveness) – for an even less aggressive blade, flip it around to back blade
3. if necessary, add some additional weight to the blade assembly so that your implement maintains its bite
4. begin in the center of your driveway and make multiple passes toward the edges – do not worry about getting every bit of snow all in one pass – easy does it
5. making use of tire chains or your Kubota’s differential lock (if equipped) will help you out if traction becomes a problem
6. if you are clearing snow and your tractor bogs a lot, this is an indication that you are 1) being to aggressive with your blade tilt or 2) the angle of discharge needs to be increased to fire more snow off the end of the blade rather than dragging it all

Adjusting the Blade Angle
All snow or grader blades are built with a sturdy frame that attaches to the tractors 3 point hitch. The blade may be fixed to the frame or it may be adjustable, allowing the operator to angle the discharge of snow, dirt or gravel off to one side. Pulling the clevis pin allows the blade to be angled up to 30 degrees left or right, across 4 or 5 discrete positions. The blade may also be fully rotated backwards. Operating the implement in this manner is referred to as back blading.

Pull the clevis pin on your snow blade to swing to another angle or to completely reverse it.

Schematic displaying snow blade attachment to 3 point hitch, clevis pin and 5 adjustment positions to give up to 30 degrees of blade angle.

Adjusting the Blade Angle of Attack
When we say angle of attack we are referring to the angle the edge of the blade makes with respect to the surface you are grading – in other words, the tilt of the blade. Lengthening the top link will change this angle of attack and make the blade more aggressive. Shortening the top link does the opposite – allows the blade to still move snow or gravel, but reduces the frequency that the blade digs in as much as much on uneven ground.

Adjusting the blade agressiveness - lengthen top link to increase blade agressiveness, shorten for a softer blade.

Blade Moldboard
Your blade might be equipped with what is known as a moldboard, like we have on our 60″ Farm King Series 30 here. The part of the blade that contacts the ground is called the moldboard and higher quality blades typically have replaceable moldboards. Once the contact edge of the moldboard has become sufficiently worn, it can be unbolted and inverted, giving a fresh sharp cutting edge once again.

We have a moldboard on the bottom of this Farm King Series 30 which allows us to 1) invert the moldboard for a fresh cutting surface and 2) replace the moldboard only instead of the whole blade.

Adding a Little Weight
Since the 3 point hitch on your tractor does not have hydraulic down pressure the effectiveness of the attached implement often governed by its weight. A blade of substantial mass will resist riding up on a hard pack of snow or dry compacted earth. Providing you do not exceed the maximum lift capacities of your 3 point hitch (measured at the ball tips), then adding a little weight to either the blade frame, the blade itself, or both, can greatly improve the ability of the blade to function. We have short sections of railway track bolted securely to the frame and the blade to give us this extra weight for best results.

It goes without saying that no one should ever ride on a snow blade, or any implement for that matter. Generally no one should be at the rear, working end of a tractor.

Gravel Driveway or Parking Lot? Consider Back Blading
You may want to consider back blading if you are clearing snow off a gravel driveway or parking area. When the snow blade is rotated backwards it will operate in its least aggressive fashion. The blade will not cut into the roadway and will not accumulate gravel in the blade. You will still be able to move a large volume of snow and if the blade becomes overwhelmed with product it will slightly ride up and slide over the snow, rather than bogging down your tractor.

Service Department Vic

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If you are old enough to drive then you know the basic idea behind a clutch – it is a component of transmission that is designed to allow the engagement or disengagement of the engine to the gearbox. Without a method of temporarily disconnecting these two assemblies you would not be able to shift gears or change direction of travel – both very handy features of your Kubota tractor.

Depending on the model of Kubota tractor you own it will have either a dry clutch or a wet clutch.

Wet Clutch
Certain Kubota tractors use a multiple plate wet disc clutch system that is in-place of the dry clutch. This hydraulic wet clutch offers exceptional durability and a much longer operating life compared to a single dry clutch disc. The wet clutch has a steady stream of filtered hydraulic oil that keeps the clutch discs and plates cool, reducing friction for smoother operation. A mechanically actuated shuttle valve controls the directional flow of oil, allowing the operator to shift between forward and reverse gears without clutching. Kubota’s L2550 or L2650 are two examples that employ a wet clutch.

This image is an example of a wet clutch pack. We see two gear packs - one forward and one reverse. The entire unit is bathed in a lubricating oil.

Dry Clutch
Dry clutch Kubota tractors are ones that operate with a dry asbestos friction disc material. The friction material is pressed tightly against the tractor’s flywheel using springs. They do not last as long as their wet clutch counterparts, but they are cheaper to repair or replace. It is also possible to rebuild a dry clutch and its common to have the disc resurfaced. Most of Kubota’s model lineup use dry clutches. B5100, B6100, B7100, B5200, B6200, B7200, L175, L185, L1801 and so on – all examples of dry clutch Kubota tractors.

A typical dry clutch with asbestos friction material. The springs relieve load shock and help smooth clutching action.

Kubota’s “Ever Clutch”
The L2650 is an example Kubota that was available with either a wet or dry clutch. L2650s with an “Ever Clutch” decal were fitted with the longer lasting wet clutch system – hence the “Ever”. Other Kubotas that were branded with this decal and the upgraded clutch were the L2950, L3450, L3650, L4350, L4850, L5450, M5700 and M6800.

Components of a Dry Clutch
Dry clutches make up the majority of those found in typical Kubota equipment, so it is these types that we will focus on for the remainder of the article. The dry clutch on your Kubota tractor comprises the following main components:

• flywheel
• clutch disc
• pressure plate
• clutch release or throw out bearing
• clutch release fork

Flywheel
The flywheel is a heavy metal disc that is attached to the crankshaft at the rear of the engine. It is precision balanced and of a substantial thickness – typically around 1.5-2″ thick up to 3″ thick on a Kubota M series. These flywheels weigh about 40lbs in a small L series, 55-65lbs in a Grand L series and upwards of 125lbs for the larger 100HP M series.

Flywheels in your Kubota are 1.5-2 inches thick and typically weigh around 40-50lbs. They store momentum which steadies varying amounts of torque placed on the input shaft of the transmission by the engine.

The flywheel stores momentum which means it is able to steady the input shaft of the transmission by smoothing out fluctuating amounts of torque placed upon the shaft by the tractor’s engine. It also has a ring gear with teeth that accepts the starter motor’s drive gear when cranking the engine. A common Kubota service complaint regarding the flywheel is poor starter motor engagement from a worn motor pinion or a badly worn ring gear. In this case, often a shudder is felt when releasing the clutch on the tractor. This shudder indicates an imbalance in the flywheel due to general wear or a flywheel that has been machined down in the past and is now over its acceptable tolerance.

Point where the starter's drive gear (smaller gear in center) contacts the flywheel.

A flywheel that is not able to properly dissipate heat extremes will eventually stress-crack. The generated friction can also temper areas on the flywheel resulting in hot spots. These hot spot areas appear as blue burn marks on the surface of the flywheel and indicate a flywheel that is not handling heat properly.

A flywheel with stress cracks due to temperature extremes.

A flywheel with friction hot spots burned into its surface.

Flywheel Resurfacing
If you are undertaking splitting of your Kubota tractor to service the clutch it is recommended that you resurface the flywheel – paying particular attention to the appropriate minimum thickness requirement. Kubota further states that the maximum amount of material that can be removed from any flywheel clutch surface is .060” (1.5mm). Post a comment if you require a specification for your Kubota’s flywheel and we’ll reply!

Clutch Disc
The clutch disc is comprised mainly of compressed asbestos with metal filings. This disc is held tightly against the flywheel by the pressure plate. The clutch disc is always in contact with the flywheel and as such, is subject to wear and slipping. Some common Kubota tractor service complaints with the clutch are slippage – due to disc wear, contamination from oil or from hot spotting on the flywheel.

Schematic of a Kubota clutch disc.

Oil on the Disc
Oil can contaminate the disc from a bad rear engine main seal, or a bad transmission input shaft seal. Either way, oil on the disc is not good. Oil can also enter the clutch housing area and contaminate the clutch disc by over filling the transmission. The L-1 Series Kubotas, L2050, L2550, L2650 and so on, have a vent hole near top of the transmission, above the input shaft and contained in the clutch housing. Overfilling the transmission/common reservoir will push oil into this area which would then contaminate the clutch disc.

Riding the Clutch
Operators can prematurely wear out the clutch disc in their Kubota tractor by “riding” the clutch pedal. This results from not removing your foot from the pedal when shifting gears. You’ll know the smell of a burning clutch when you smell it – it smells expensive. Avoid riding the clutch by keep your foot on the foot board.

When to Replace the Clutch Disc
Signs that your clutch disc needs replacement:

• inability to shift the transmission with the engine running without grinding the gears
• the tractor will not pull a load
• the tractor will not go up a simple incline
• slipping, extreme shudder or squealing
• expensive burnt clutch smell

Storing your Kubota? How to Prevent the Clutch from Rusting to the Flywheel
Kubota recommends that when storing your equipment, have the clutch disc pressure relieved by way of placing a block under the foot board after the clutch pedal has been depressed. This relieves the pressure on the clutch and prevents it from rusting to the flywheel. A clutch rusted to the flywheel is common service complaint is for owners of seasonal Kubotas (only use it in the winter to snowblow or only in the summer to mow). They may use their Kubota so infrequently that when they do attempt to start the tractor, the clutch and transmission are frozen – rusted together.

Kubota recognized this service issue and shipped all L175, L185, L235, L1500, L1501, L1801 and L2000 tractors with a small wooden block, painted black included in the under seat tool box. The block of wood had a yellow decal on it that indicated the correct placement of the block in keeping the clutch pedal depressed during storage. A paper tag with wire was attached to the clutch pedal further reinforcing its use if the tractor was stored and not used for any period of time. Later models like Daedong and Kubota’s joint venture, the 02 Series (L1802, L2002 etc), had a spring button that when pressed down, held the clutch pedal and kept the disc off the pressure plate.

Condensation & Free Play Considerations
Condensation in the clutch housing also creates a problem for the clutch disc. There is a drain at the bottom of the housing that should be opened from time to time to let water egress. If you have an early L175/L1500 and there is no drain plug, drill a small hole at the bottom of the housing to necessitate the removal of condensate from the clutch. Finally, clutch pedal “free play” should be adjusted from time to time as the tractor ages and the disc wears. Post a comment if you require a specification for your equipment.

Pressure Plate
The job of the pressure plate is to maintain constant, even pressure on the clutch disc, holding it in contact with the flywheel. The pressure plate has a precision-ground machined surface that the clutch disc contacts on the transmission side. At the centre of the pressure plate is an array of tensioned spring fingers. When compressed by the clutch release bearing, tension is alleviated on the disc plate and it is then free to rotate, independent of the flywheel. This allows the operator to change gears, or direction of travel.

Some common Kubota service complaints with the pressure plate are similar to those of the flywheel:

• shudder – from hot spotting on the pressure plate’s machined surface
• a mushy feeling – indicative of broken or worn springs
• excessive pedal travel
• inability to change gears
• grinding of the transmission even though the clutch pedal is fully depressed

A schematic of a Kubota pressure plate.

Clutch Release Bearing and Shift Fork
The clutch release bearing is a precision roller bearing that rides on the transmission input shaft of your Kubota tractor. It is held in place and activated by the clutch fork which in turn is attached to the clutch pedal linkage.

A close up shot of the clutch release bearing.

The clutch fork straddles the clutch release bearing holder.

The large flat face of the release bearing presses against the spring fingers of the pressure plate to free the clutch disc. Some common Kubota Service complaints with the clutch release bearing are squealing, grinding and chatter when the clutch pedal is lightly pressed, or pressed a little too far (clutch pedal stop is not adjusted properly) and the squeal can persist during travel with the clutch fully engaged.

B Series Kubota tractors have a serviceable release bearing. A grease zerk is accessible from the side of the transmission tunnel. A few strokes keeps that bearing moving freely. Use care not to dislodge the small return spring attached to the bearing.

All or Nothing
If you find yourself in a situation that necessitates the splitting of the tractor to get at the clutch then you should consider replacing all of the serviceable components in there. Do not just install or have installed a new clutch disc. Replace it with a matched pressure plate and have the flywheel machined to the correct spec. Emery cloth and a lot of ambition does not machine a flywheel. When it comes to a Kubota clutch it is best to take an all or nothing approach to its repair – you’ll thank yourself in the long run.

That wraps up our overview of the different types of clutches in Kubota’s equipment and an in-depth look at the mechanics of the dry clutch found in most Kubotas. Read more about your clutch in the related articles below.

Service Department Vic

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Forum: Service, Repair & Maintenance

Credit goes to Bill from www.dieseltraders.com.au who helped us clarify some of the technical details in this article.

The Role of the Differential
This is a quick article that discusses how to engage your Kubota’s differential lock and why you might want to do so. But first, we must understand what the role of your Kubota’s differential is, and why we can get into a situation were we lack adequate traction.

When you turn the steering wheel to make a turn, the inside tires travel a shorter distance than those on the outside – they are traveling at different speeds. The differential equipped on your Kubota allows your tractor to turn because it lets the rear tires rotate at different speeds. Without it, handling your Kubota would be very difficult and wear or damage to the tires and drive train would likely occur.

Your Kubota is equipped with a non-limited slip or open center differential – that is, your differential will favor the wheel that is easiest to turn. This allows us to steer around, but, it also means is that if one wheel starts to loose traction or comes off the ground completely, the differential will send most of the engine’s power to that free wheel. Traction is lost.

What does Locking the Differential Do?
Most Kubota tractor’s have the ability to lock the rear differential. This simply locks both rear wheels together and drives both of them simultaneously without the possibility of one side free wheeling. The differential is no longer favoring the wheel easiest to turn – it is sending power to both. Note – the engine’s power is not increased, but, the power it is generating is better used because your Kubota has a better grip and is not freely spinning.

How to Engage the Differential Lock
You engage the lock by stepping down with your right heel onto the differential lock pedal. If the tractor is not running and the gears in the differential are not turning, the pedal will not depress fully. During normal operation that pedal will depress fully and engage the lock providing that boost in traction.

When to Use the Differential Lock
Because the differential system on your Kubota allows the rear tires to turn at different speeds, locking the differential should only be used when traveling in a straight line. If you lock the differential and then attempt to turn, you put extra strain on the differential lock, possibly leading to its or another component’s failure.

You should lock your differential whenever additional traction is required – like in slippery or snowy conditions or when you are bogged down in the mud. Although additional traction that the differential lock provides is handy, it is a good idea to use the lock only when necessary and for short periods. The planetary gears in the differential generate more heat and when the lock is engaged, so do not just drive around with the differential locked during normal work.

Service Department Vic

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Cold Weather Starting Tips
How to Install Tire Chains on your Kubota

The arrival of winter. Subzero temperatures across Canada and the United States. Time for a refresher course on how to get your Kubota tractor starting in cold weather. We will assume that you are already using the appropriate cold weather diesel (or the correct additives) to prevent your fuel from gelling.

Prevention
There are a few things as a Kubota owner that you can do to help yourself when it comes time to start your tractor up in cold weather. They are:

• park your Kubota in a shed or garage
• install and use an engine block heater
• use a fully charged battery

Parking your Kubota
Simply by parking your tractor inside a shed or garage you help keep the wind and cold away from the engine. It is also a lot more comfortable to work in a garage when it comes time to get your tractor to turn over. If you do not have access to a shed or garage, even a treed area that cuts the wind a bit is better than leaving your equipment in the open.

Engine Block Heater
Some Kubotas come equipped with a block heater from the factory, others, like the L175, L185, L1500, L1501, L2000 and so on, do not come equipped with these. The reason being is that the water jacket on these models is too shallow to accomodoate a block heater. Admittedly, it was a manufacturing oversight on Kubota’s part. In either case, it is possible to purchase a magnetic block heater from a local auto parts supplier and attach it to the bottom of the oil pan. It will heat the oil and the warm oil will warm the block and water jacket. Having warm oil also means the engine and starter do not have to fight against thick cold oil during cranking. The magnetic heaters that we use are 1500 watts, substantially more than the 75 watt factory-equipped heaters. Figure on paying around $30-40 for one of these aftermarket heaters.

Charged Battery
A battery’s ability to provide full cranking power degrades as the temperature drops. If your battery was not 100% charged or is in poor condition to begin with, the cold will only make that problem more apparent.

Glow Plug Preheat
The glow plugs in your Kubota serve to preheat the combustion chamber so that the diesel fuel will ignite and kick off combustion. After the engine is turning the compression of the engine spontaneously causes the fuel to combust and the glow plugs are no longer heated – they are just used to start this process. To preheat the glow plugs we turn the ignition key counter-clockwise and hold it there for a period of time. In cold weather, we recommend at least 60 seconds of glow plug preheat. Most Kubotas are equipped with a preheat indicator that will light up when the glow plugs are heated.

Cranking
After preheating the glow plugs for 60-90 seconds, fully depress the gas pedal and begin to crank the engine. If the engine fires but it running choppy or “lumpy”, it is okay to turn the key back to the preheat position to heat those plugs up again. If it is very cold and the battery has lost its effeciency and is having trouble turning the engine over, its a good idea to use the cylinder head decompression knob located on the dashboard (L1-18, L1-20, L1-22, L1-24, L1-26 series are not equipped with this option). This relieves the cylinder head of some of the compression, allowing the weakened battery to turn over the engine a little easier because it has less compression to contend with.

A Word on Ether
Many years ago it may have been common practice to introduce ether into the airbox during cold weather cranking to kick off combustion. This is no longer the case for your Kubota engine. Introducing ether in this manner will seriously damage your engine and shorten its working lifespan. The combustion that results from burning ether is so volatile that a high compression diesel engine will freely race uncontrollably until that fuel is spent – turning the key to the off position or no longer heating the glow plugs will not stop that reaction. Diesel fuel is an oil and lubricates the inside of your engine – a property that an alcohol like ether does not have. Just do not use ether to start your Kubota in cold weather period.

Let it Idle
In cold weather, after your tractor has started, let it stand and run for a good 20 minutes. Adjust the idle up to around 1500-1700 RPM and just let it sit. The reason we do this is so that the heat of the engine dissapates into the transmission, transfer case and gear drives of the tractor. If we went to work right away, the gear oil is so thick that the hydraulics will not work and shifting gears is problematic. A common service task is to repair a shifter fork during a cold weather season – the gear oil is so cold and thick that when the operator grabs the stick to put the tractor into gear, the shifter fork breaks off inside the transmission – costly. Let the tractor warm up for a period of at least 20 minutes when in cold weather.

Taking a Break? Let it Run
Suppose that you’ve warmed up your Kubota, done some work and now want to shut it down to take a break and return 10-15 minutes later to start it up again. In this case, we recommend that you just let your Kubota idle. It will not overheat and at idle it uses very little fuel. Taking a break with the engine off, might mean that you have to let the tractor warm up again for that 20 minute period anyway.

Service Department Vic

Related Articles
Are you “gellin’”? A Tip for Cold Climate Kubotas
Trouble Starting your Kubota? Skip the Starting Fluid.
How to Use your Kubota’s Differential Lock
How to Install Tire Chains on your Kubota