TG1860 Mower with rattling noise under seat area

[TG1860]

Hello, I'm Andrew and live in the Greenwood SC area. I own a Kubota TG1860 diesel 54" mower that I bought new 20 years ago. It now has 612 hours, so I'm averaging about 30 hours per year. For the most part this thing has been trouble free, except for adding the John Deere ignition solenoid due to failure to start and the fluid changes and all.

Recently it has developed a rattle under the seat area that seems to be coming from the gearbox that transfers power from the engine to the hydrostatic transmission and the mower deck. It seems this probably has bevel gears to transfer the incoming horizontal motion to the vertical driven pulleys. But it could be the transmission I guess. What's it take to diagnose this rattle and rebuild the gearbox if that is the concern? Where is the oil inlet to the transmission and what kind of oil to top it off? When not in use this mower sits on concrete and I've seen no evidence of leakage anywhere, so I don't believe it's run dry, but it'd be good to check.

Today I figured it wouldn't take but a few minutes to remove the sheet metal the seat sits on, to look around, but it seems that's not so easy to do. I don't want to do unnecessary work, so I am turning to you guys for help.

 

[ve9aa]

The inlet is right beside the pulley. You won't find it under the seat.

Kneeling down at the back of the mower, look to the left of the pulley and you'll see a 4" or so hose sticking up almost vertically, but bending to the left with a vent cap on it. That's where to fill it. Don't put too much in( got too much in and it burped fluid all over my belt)

IIRC (and you should double check this) I put 90W in it....but it's been a while, I could be wrong.

My 1860 (D) has about 965hrs on it.

I also found I could get more speed out of it using a slightly undersized belt from Princess Auto (Canada) or probably your Harbour Freight as the right belt always slipped. At first I thought it was the hydrostatic transmission...which led me to the oil filler tube. And I never did figure out how to (properly ) check the level. Don't get any on the drive belt...for obvious reasons.

I never did hear a rattle, so likely a different issue than yours. Almost sounds like a loose pulley or some bracket that's about to fall off !

HTH

 

[Russell King]

You may want to look at illustrated parts list at Kubota USA to see what is in the area. I always suspect pulleys when it is a rattle but there may be a rod or plate loose from its pin?

 

[TG1860]

@ve9aa I see the hose sticking up and believe it to be a vent tube. It never occurred to me that I would top off the fluids through this hose. And with no dipstick or side mounted overflow plug how do I know how much, if any, I need to add?

Concerning your suggestion of the shorter belt: About 15 years ago this mower was slowing down when pulling hills, sometimes to a complete stop. My 2.5 acre yard isn't real hilly, but there are some. I self diagnosed it as the hydraulic filter clogging up so went to the Kubota dealer to purchase filter and fluid. I described the concern to the counter guy and he just smiled and sold me the parts.

I removed the transmission's bottom plate to remove the oil and access the filter. As others have mentioned one of the fasteners twisted off in the aluminum housing.

Anyway, I replaced the filter (realizing it's mesh metal and could have easily been cleaned and replaced) and reassembled with fresh oil. But it didn't fix my problem, the mower still lost speed when climbing hills.

Somehow I determined the belt driving the hydrostatic transmission was slipping. (A much easier fix than replacing filter and fluids) But the new belt from Kubota didn't completely rectify the problem. So I took the belt to the local NAPA store requesting a belt slightly shorter. They sold me their Heavy Duty 4L430W belt which rectified the concern.

@Russell King I'll see if I can download an illustrated parts list to learn what the internal parts look like. And again check for something lose. But this noise is there when the engine is revved up. It doesn't change when engaging the mower deck or moving the mower forward or back. That's why I'm thinking it is in the power transfer box between the engine and the transmission. This box likely contains bevel gears to transfer the power from the horizontal drive shaft to the vertical shaft driving the pulleys. I've not seen a method to check or top off the fluids within this box.

Update: I do find a plastic plug on the top back LH corner of this transfer box. Unscrewed it and it's a dipstick too. I wipe it off and dip it in and the oil is a little low. What kind of oil might this motion transfer box require?

 

[ve9aa]

I don't know the correct method to determine the hyd oil level in the gearbox, but mine leaks...ever so slightly, as I have a tiny puddle in my shed where the mower lives. I can see it leaking out onto a pc of plywood over the course of the summer, so when it starts to slow down or make noises, every few years I add "a little" more. Last year I added TOO MUCH, got it on a belt, and well, you can guess what happened.

As it happened, this was when the dealer was closed, so I went to Princess Auto (think Harbour Freight) and bought a belt that was (I think) 3/8" or maybe 1/4"...I just forget exactly, shorter, hoping it would fit. The thing has never driven so quickly !

I've never heard the rattle you describe, so can't say what that is.
If it was me, with the mower parked and off, I'd first try shaking things and see if pulleys or brackets are loose. GRab and shake whatever you can.
or
with it running....park the thing up on jackstands, HST pedal engaged (brick) and front wheels blocked, to see when the rear wheels are spinning if you can (carefully!) get close enough to actually see/hear what's making a racket in your driveline. Sometimes a chunk of garden hose, say 5' long, held up to your ear, can be used as a direction finder for honing in on sounds.....this may help you narrow down an area that's making noise without getting your hair or body parts hooked into spinny bits. (bad, very bad)

Hard to diagnose some noises when you're buzzing around the yard, mowing, right?!

Safety first ! I assume no risk.

May the force be with you.

 

[TG1860]

I've removed both belts and cannot detect any rattles of concern. I detected some leakage on the top back center of the mower deck, it's been catching the occasional drip from the input shaft of the power transfer box.

I talked with the local Kubota dealer rep who said based on their experience it may be a worn out bearing(s) and seal(s). He said the bevel gears are probably okay. He says they probably have the needed parts in stock.

He says to use 80-90 weight oil, and to check the oil by screwing in the dipstick/plug then unscrew and see how it reads. When doing this my oil level is toward the low spot, but enough for the short term.

I may try running it some while sitting on jack stands and rear wheels removed to see what noises I can find. I have a stethoscope for this purpose, but the darn thing is so sensitive it blasts my ears if I bump anything.

So I'll need to mow twice again before tearing it down for rebuild. It would have been much nicer to have known this during the winter months when I didn't need the mower.

Thanks for the help guys!

 

[TG1860]

By removing the mower deck belt and the hydrostatic drive belt I've positively narrowed the rattle to the gearbox between the engine and transmission. Yesterday I mowed the grass and now I have more oil splattered on top of the deck, so the gearbox's input shaft seal is leaking.

I've decided to let the local Kubota dealer complete the repair. This morning I removed the deck and trailered the TG1860 to their shop.

Hopefully with new bearings and seals I'm good-to-go. If they have to replace shafts and bevel gears I figure the price will quickly get jacked up.

 

[lugbolt]

if u have to replace gears and shafts, it's cheaper to replace the entire gearbox as a unit--assuming it's still available.

 

[TG1860]

Because I was out of town last week and didn't have time to work on this I carried it to the local Kubota dealer. They found the bearings shot and bevel gears worn out, probable because of the bearing going out.

To repair they remove one from a mower in their Kubota "graveyard", determined it was in good condition, and installed in my mower. In a quick test in my yard it is functioning as it should.

I requested and brought home the box that was removed from my mower. I figure I might rebuild it for a swap out later if this used one grenades itself. I don't know the number of hours or year model of the donor mower and am hoping for the best. It may or may not last.

My TG1860 diesel is solid and it's worth it to me to keep it going.

Where can I get a parts list and pricing for the parts to rebuild this thing?

 

[Russell King]

Go to https://www.kubotausa.com/
Then to illustrated parts list and type in the mower model or the tractor model. If you use tractor models there is something called local options and under that is the accessories that will fit your tractor, select the mower deck model there find gear box section and they may have parts individually and in groups (kits) so you may be able to get a repair kit under one part number. You may need the serial number of your deck or tractor

 

[GeoHorn]

Save your money. The dealer was just-inside your gearbox and inspected and replaced everything that was needful of replacement after 20 years of use. It’s so-unlikely that your spending money/time on a “spare” gearbox will ever prove worth the time and money inside your ownership of the machine.
Plus, if that does not prove true, then by the time you wear out the rebuilt gearbox you’ll have a desire for a different machine anyway. (I can’t tell you the numbers of stuff I’ve rebuilt and stored for decades in the off-event that I’ll suffer the same failure a second time. The shop was full of junk in my way... (Thank Craig for his list for finally converting it back to real money....I could have avoided loss-of-inflation and storage space if I’d just thrown that stuff away years ago.)
IMO

 

[TG1860]

Thanks Russell. I did find an exploded drawing and parts list for this specific gearbox. I'll study it for parts.

 

[TG1860]

GeoHorn, you might be right. But the dealer didn't rebuild my box, but replaced it with a box from their junkyard. Although he did say they checked out this box and found it to be solid. Maybe it'll last another 10 years.

In looking through the exploded drawing I see I didn't get back many of the parts that might have been reused including the vertical shaft, circular clips, and spacers. If I was able rebuild with only bearings, seals and bevel gears it probably wouldn't cost too much for parts.

I'll set it aside for now. Thanks to all for you for your help.

 

[Russell King]

Glad to hear that you have it back in good condition now