bevel gear/ring gear matching set replacement

breenfarmer77

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Equipment
Kubota L35 tractor
Jun 26, 2016
13
0
0
Durango, Colorado
I am in the midst of repairing the 4x4 on my landowner's L35. The front bevel gear splines as well as the coupler splines have worn to the point of freely spinning. I'm considering a couple things including possibly just using a new coupler and let it wear down the final bit of spline metal on the bevel gear to get me through the winter as the quickest cheapest fix. I also am considering to cut the intact side of the coupler (the half which was connected to the propeller shaft to the rear) and weld it to the new coupler to lengthen it enough to actually have about 1/4" more grip on the original spline cutting which are not worn as the coupler only reached about 3/4 of the length of the shaft. The final option is to replace the entire bevel gear which I have removed. This last option is the best option of course but seems that it may then also require replacing the ring gear inside the axle housing as well and all the adjustment that that also requires. I'd prefer to do the job as right as possible and yet I am here for some insight and direction.

Do I absolutely need to replace both the bevel gear and ring gear? I know they are a matching set and have read on another blog various opinions as to the importance of ring gear replacement or not.

I ask because the tractor belongs to my landowner who is grumbling with me about the cost of the 4x4 having ceased to work. The splines on the bevel gear in the front axle are worn to almost nothing as are the splines on the coupler to the propeller shaft. She thinks I didn't do maintenance on the 4x4 and doesn't want to pay for the parts. I'm trying to explain to a 73yo woman that there is no maintenance on this other than replacement when the wear and tear of operation finally forces replacement. I've used the tractor probably no more than 50 hours in the last two years that I've been her renter and am the one holding the bag on the thing when it ceased to work. I've got it torn apart in my neighbor's shop and have ordered all the parts from Coleman Equipment. Their customer service has been fantastic to say the least. I want to let her know that the parts have likely been the exact ones that originally were installed on the tractor and that she got XXXX number of years out of them and that she should be the one paying the $500 in parts. Heck, I'm saving her a bunch in labor costs as the local dealer quoted $3000 for labor and $1100 for parts. She's threatening to boot me off the property for not being the caretaker she needs. Any insight is greatly appreciated.
 

breenfarmer77

New member

Equipment
Kubota L35 tractor
Jun 26, 2016
13
0
0
Durango, Colorado
Oh yeah, I was also kind of wondering about finding a machinist who could weld up some metal on the shaft, lathe it back to right diameter and then recut the splines. This would keep me from having to possibly disassemble the entire contents of the axle to get to the ring gear to replace it. If indeed it is critical to make sure it is a matching set. I'm not a mechanic but am borrowing the shop, time and expertise of a friend and neighbor farmer who has done pretty much all of his own repair on his 5 tractors for his entire life. His sense is to replace the ring gear but if we do that then I'm essentially relying on his time and assistance to reset all the spacers, etc. He won't take payment, which is nice of him, but I want to keep our relationship in balance and not overdo his generosity.
 

North Idaho Wolfman

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She's threatening to boot me off the property for not being the caretaker she needs. Any insight is greatly appreciated.
You must really like the place if your going to put up with someone's threat to boot you off it for parts wearing out on a tractor! :confused:

The parts didn't wear out in 50 hours or 10 times that.
And probably was from running in 4wd on hard surfaces, a long time.

Yes you need to replace them as a matched set.

Your chances of finding someone to do that kind of machine work would be about impossible and if you did it would not be cheap as splines are very hard to cut.

It's a poor fix compared to replacement, but you would be better off drilling (if even possible) through the coupler and the shaft and installing a roll pin!
 
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sheepfarmer

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Breenfarmer, there is another perspective here, being a 73 yr old woman myself, and that is she may have seen various employees and renters cowboy her equipment carelessly. After having one employee run my Gater into a fencepost and cracking a fender ( he was busy talking to another guy) and the lawnmower into a septic tank stand pipe, breaking it off and the steering gear on the lawn mower, ($900 for the latter fixes) hell would freeze over before I would let him or anyone else on my Kubota. You may not have been careless with the tractor but someone else probably was, and you are getting the short end of the stick. If you are as competent at repairing things as you sound, marshall your facts, lay them out with diagrams if needed and do a good job to set the tractor right. Deal with the grumbling, it goes with the territory.


I am in the midst of repairing the 4x4 on my landowner's L35. The front bevel gear splines as well as the coupler splines have worn to the point of freely spinning. I'm considering a couple things including possibly just using a new coupler and let it wear down the final bit of spline metal on the bevel gear to get me through the winter as the quickest cheapest fix. I also am considering to cut the intact side of the coupler (the half which was connected to the propeller shaft to the rear) and weld it to the new coupler to lengthen it enough to actually have about 1/4" more grip on the original spline cutting which are not worn as the coupler only reached about 3/4 of the length of the shaft. The final option is to replace the entire bevel gear which I have removed. This last option is the best option of course but seems that it may then also require replacing the ring gear inside the axle housing as well and all the adjustment that that also requires. I'd prefer to do the job as right as possible and yet I am here for some insight and direction.

Do I absolutely need to replace both the bevel gear and ring gear? I know they are a matching set and have read on another blog various opinions as to the importance of ring gear replacement or not.

I ask because the tractor belongs to my landowner who is grumbling with me about the cost of the 4x4 having ceased to work. The splines on the bevel gear in the front axle are worn to almost nothing as are the splines on the coupler to the propeller shaft. She thinks I didn't do maintenance on the 4x4 and doesn't want to pay for the parts. I'm trying to explain to a 73yo woman that there is no maintenance on this other than replacement when the wear and tear of operation finally forces replacement. I've used the tractor probably no more than 50 hours in the last two years that I've been her renter and am the one holding the bag on the thing when it ceased to work. I've got it torn apart in my neighbor's shop and have ordered all the parts from Coleman Equipment. Their customer service has been fantastic to say the least. I want to let her know that the parts have likely been the exact ones that originally were installed on the tractor and that she got XXXX number of years out of them and that she should be the one paying the $500 in parts. Heck, I'm saving her a bunch in labor costs as the local dealer quoted $3000 for labor and $1100 for parts. She's threatening to boot me off the property for not being the caretaker she needs. Any insight is greatly appreciated.
 

RCW

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BX2360, FEL, MMM, BX2750D snowblower. 1953 Minneapolis Moline ZAU
Apr 28, 2013
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My first question is how many hours on the L35?

If somebody beat the shyte out of the 4WD for 800 hours before you got there.......

Unless you've been doing Figure 8's on dry pavement in 4WD for ALL of those 50 hours - didn't get torn up on your watch, just stopped working at an inopportune time for you!

And my only experience is pickup rear-ends, but I would replace both parts with new.

Good luck!
 
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breenfarmer77

New member

Equipment
Kubota L35 tractor
Jun 26, 2016
13
0
0
Durango, Colorado
I've been pretty gentle with the tractor and use it mostly on pasture for mowing some sections with sage and rabbit brush. I also use it to turn a number of large compost piles and in the winter (mainly last year's winter) to plow snow off the driveway of 1/2 mile length. She and her husband (he died a few years ago) bought it used about 10 years ago and from what I understand he was the primary user. It was pretty beat up when I moved on the property. I definitely love the property and have been using Holistic Management as our guide to build soil and develop pasture by rotating 6 different animal groups almost daily throughout the Spring, Summer and Fall and I have a desire to buy the place when I can afford it. I treat the tractor as if I own it as some day I may very well. It does not have an hour meter so I'm not at all certain but it must be plenty. She does go through a winter depression so I factor that in regarding getting booted off the property. I'm a learning mechanic and yet have found that with youtube, forums like this and neighbors I can just about fix anything. Troubleshooting electrical stuff is my most difficult challenge. Heck, I even replaced the starter of her Honda CRV which required removing the intake manifold. Youtube got me through that one just fine. I guess I'll be learning how to replace the ring gear and keep them a matching set. I do like the drill and roll pin idea to maybe squeak out a few more months on the current bevel gear until I replace the whole thing. The bearings looked fine. Wish there was some kind of shear pin to replace instead of the whole bevel gear bit. Thanks much for all the input.
 

mfljr

New member
Apr 7, 2016
7
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TX
I do like the drill and roll pin idea to maybe squeak out a few more months on the current bevel gear until I replace the whole thing. The bearings looked fine. Wish there was some kind of shear pin to replace instead of the whole bevel gear bit. Thanks much for all the input.
If this is really the goal here, then just replace the bevel gear and go on with your day. It's a tractor, not a highway axle.

Would it be "best" to replace them both, absolutely.

Will it work for a reduced lifetime if you don't, probably.

Run it in 2wd as much as possible, and just replace the bevel gear and you should be able to 'squeak out a few more months'.

A contentious operator can make less than perfect machinery last for a very long time sometimes.
 

Lil Foot

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1979 B7100DT Gear, Nissan Hanix N150-2 Excavator
May 19, 2011
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Without pics, not sure of the exact location of the possible roll pin "fix", but make sure it is not a sliding splined joint. Pinning a sliding joint will cause a whole host of disastrous results, and you will be way worse off than you are now.

And I agree with the above post, best to replace them as a set, but if you absolutely can't afford to, replacing part of the set will work; for how long is anyone's guess. It is a low speed application.
 
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breenfarmer77

New member

Equipment
Kubota L35 tractor
Jun 26, 2016
13
0
0
Durango, Colorado
Once again, thank you all for your responses. I have one final request for info (I hope it's a final one anyway).

I have decided that my integrity won't allow me to do a half ass job out of retribution nor just to get me through this winter so I'm going to replace the ring gear as well. My question would be of anyone who has accomplished this task. I know that the whole set of "stuff" that will need to be removed from inside the axle tube to get to the ring gear has collars or spacers to get the ring gear set at the correct depth to match up with the bevel gear. Does anyone have a sense of how many different sizes of collars/or shims are needed to get that distance set correctly? I have ordered 5.9, 6.0 and a 6.1mm collars for setting the bevel gear to the correct depth to match with the ring gear but I'm certain I'll need to have a few different sizes of collars and/or shims for setting the ring gear as well. My buddy who's shop I've got the tractor jacked up in right now has only John Deere tractors and his use a series of thin shims to set the right depth and I see shims in the exploded view of the differential gear diagram. I can't really afford the $130 or so for the workshop manual. I doubt the manual specifies it anyway since each matched set comes out slightly different and so it must just come down to setting and resetting until the correct backlash has been established. I have only just even comprehended these terms so anybody who has done this job and would be willing to provide insight I'd greatly appreciate it. My neighbor buddy is a full time farmer/rancher who has graciously extended the use of this shop, tools, time and knowledge without request for compensation of any sort so I feel like I need to be able to accomplish the bulk of the grunt work of this and only ask for his time when I've no clue how to proceed, (ie. establishing backlash, etc.) If I can either get the collars locally or from Coleman's Equipment ahead of trying to reassemble the ring gear and all the stuff behind it I'd be sitting pretty well. A final question would be to ask if the removal of the wheel front axle case and everything else necessary to access the ring gear assembly "stuff" will need to have any parts on hand to replace (o-ring, seals, etc.)? This job just got bigger and more expensive. Since I've got all the stuff taken out would it make sense to so any work on the two front axle cases for both wheels? Not sure the name of the assembly I'm talking about the the parts list calls it the "bevel gear case". Hope I'm making sense
 

lugbolt

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Equipment
ZG127S-54
Oct 15, 2015
4,884
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Mid, South, USA
I've had request from customer in the past, they wanted me to replace the pinion only and leave the new ring gear in the bag and just give it to them....for time constraints only. Why I don't understand because the ring gear has to come out to replace the pinion. But anyway...did what was requested. Boy was it noisy. Seems like he got 100 hours +/- out of it before it was junk again.

Hypoid gears are factory designed to work together, as a set. They develop a wear pattern pretty quickly, and the wear pattern on used gears slightly changes the shape of the gear teeth. This is most specific to hypoid gears; not so much worm, straight cut or straight bevel gears. Using a one new gear combined with an old one is a guarantee for noise, and probably failure at some point.

do it right, or just don't do it.

Most of the time reusing the original shims and colars will get you really really close. Lots of times (in my case), right on the money with the original shims and collars.

The L35 is so easy to deal with that there's no sense in doing it halfway anyway. The worst part (IMO) was flushing all of the junk out of the hubs. Any metal particles usually find their way to the bottom of the hub assemblies, then eats up the support bearing.

Be sure to get a new pinion seal, so that you have it on hand when you go to reassemble. I also like to get new pinion bearings but that's me. Old ones aren't hard to press off. I heat the new bearings in the oven (or a hot plate) to about 250-300 degrees, and they'll slide on without a press.
 

North Idaho Wolfman

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Most of the time reusing the original shims and colars will get you really really close. Lots of times (in my case), right on the money with the original shims and collars.
I was going to say the same thing, it's normally the case that is not to an exact spec, so the shims and collars are set to the case so the old ones should bring it right back into specs. ;)