B7100 locks up in 2WD

[N3BP]

Hey guys,

Was hauling a small trailer today. Had about a half ton of wood in it. My procedure for getting it up the back yard is to put it in 6th, 4x4 with the diff lock engaged. I need enough momentum to get it up the hill since the trailer weights more than the tractor. I guess I stressed it out too much. Was going up the hill when the tractor made a loud noise and stopped dead. Switched form 4x4 back to 2x4, something broke free and drifted back down the hill. He is where it gets really strange. The tractor only works in 4x4 now. When I pull the lever to go to 2x4 it locks up. The front wheels actually want to go in reverse when shifted to 2x4. Does it in both forward and revers, high range and low range Works just fine in 4x4. I have no clue what I broke. Bent fork maybe? Its acting like it is engaging a reverse gear.

I appreciate any help!
Brandon

 

[N3BP]

So I jacked the front end off the ground. In 4x4 one front tire spins one way, and the other tire spins in the opposite direction. Makes sense since the front driveshaft has is engaged. When I flip to 2wd, same results, so something in the transmission is locking the front driveshaft in 2wd mode.

I guess my next step is to drain the transmission and see whats broke, bent, or missing.

 

[100 td]

Yikes, I'm guessing you might find some of this horrible stuff! Hopefully just a bent shift fork or similar though. The bit where it drifted down the hill in 2x4 sounds bad!

 

[D2Cat]

If you're pulling a load up a hill why are you in 6th gear?

 

[hodge]

If you're pulling a load up a hill why are you in 6th gear?

Sounds like he needed momentum.

 

[D2Cat]

Sounds like he needed momentum.

I guess what I was getting at is if one needs momentum to get a load up a slope you probably have a mismatch between tractor's weight and power and the object being pulled.

Easy to imagine grief of some kind. If it takes momentum to get it going what is going to get it stopped every time safely?

 

[N3BP]

Yes, I needed the momentum. The grade was steep enough and the grass was wet. In all honesty, I figured the tractor was tough enough to handle the weight. Since it ran fine in 4x4, I still continued to use it all day. It would be nice to have the 2x4 for when I drive it a short distance on the driveway.

I'm also very careful going down hill. I always put it in low range and let the engine do most of the braking. But the trailer still pushes the tractor a little bit. I've done it so many times, that I feel comfortable with it.

 

[N3BP]

So I'm to the point where I'm ready to pull the transmission cover to inspect the internals. I cant' seem to get the cover off. I've searched but couldn't find anything. The WSM doesn't get into the specifics. I tried using the chain hoist to pull it off but the ropes keep breaking. Only bolt I didn't remove is the check plate bolt (black arrow). I don't think this needs to be removed.

Any tips on how to get this darn thing off are appreciated!

 

[N3BP]

Ok, it came off with some muscle. Naturally a piece of the case broke off at the alignment dowel pin location. I'm sure even after I put a new gasket on it's going to leak there.

I discovered my issue. The gear that engages/disengages 4x4 is all marred up for some strange reason. When in 4x4 the shiftier shoe doesn't catch any of the marring, but when shifted to 2x4 it does. That's what was binding up the drivetrain. Although nothing is broken, I still have to take the transmission apart and replace that gear and shifter shoe. I still have no freaking clue how this happened.

 

[Tooljunkie]

Theres going to be pieces off of something in the bottom of the gearbox.

 

[N3BP]

So I'm at the point where I'm ready to remove the gearbox from the rear-end. It won't separate. It appears that the pinion bearing is suck in the rear end housing. Anyone have tricks or tips for getting this out?

Thanks Much,
Brandon

 

[N3BP]

Ok, got it off. Here the PTO coupler was hanging it up.

So this must have happened over a long period of time. Only thing I can think caused it was someone resting their boot on the 4x4 lever repeatedly. The shifter shoe wore down and welded itself to the gear. Then it got all rough and the shoe would get caught on the gear and bind the entire drivetrain up. No metal in the bottom of the transmission case. Good thing for the used parts market because Mesicks wants $275 for that gear!

 

[N3BP]

Transmission is back together and everything is working as it should. I figured since I had the tractor split, I'd do some other maintenance to it. It needs a new throwout bearing - the old one is really noisy even though it has plenty of grease in it. I need to raise the fingers on the pressure plate, I ran out out clutch adjustment and it doesn't want to disengage 100%.

So I go to remove the clutch housing from the engine and a sizable puddle of oil pours out. The entire clutch assy is coated in oil. I figured the rear-main seal is shot. Turns out the crank has a nice groove cut in it where the seal sits on.

It appears Kubota makes a sleeve for the B7100 crank. PN# 19215-23280. The problem for me is that it is only good for ESN's above 188652, which mine is not. Anyone have any experience with a Speedi Sleeve? I'm guessing that's the route it should take? Also, has anyone every had any luck cleaning oil off a clutch disk?

Thanks,
Brandon

 

[Tooljunkie]

Speedi-sleeves or redi-sleeves are great to repair these sort of problems.
Finding the size you need is the challenge, sometimes installing can be difficult.
They usually come with an installer,and a sealant is used to lubricate them for installing. I believe i used blue loctite last time.

Cleaning oil off a disc,can be done but will never restore it 100%.
Brake cleaner several soakings,and allowed to thoroughly dry.
Be warned that some cleaners release phosgene when heated
And it can be lethal. Tetrachloralethelyne is the one to avoid.

By warming clutch with a propane torch,oil will rise to the surface that you can wipe off.

 

[N3BP]

Thanks for the reply Frank. I've been reading the tutorials online on how to properly install them. Got to take three measurements of the crank diameter and average them..etc. Already got some bearing loctite on order. Looks like it should work well though.

I also didnt realize that I can get a new clutch disk for $50.00. So I went ahead and ordered a new one. Just pisses me off sine the old one looked good except for the oil....

Brandon

 

[North Idaho Wolfman]

The crank looks fine, I don't thing that's a wear grove, it looks to be the normal machining surface, the seal rides behind that.
Now for the seal, buy genuine Kubota seal and gaskets, there is one seal and 2 gaskets, one paper one copper.

Four parts to replace the Throw-out bearing, the pilot bearing, pressure plate and clutch disk.
Replace all at once or you'll regret it.

 

[007kubotaguy]

Brandon

If you just install the new rear seal about 3/16" further into the seal retainer the seal will ride on a new area. We do it all the time.
Good Luck Lance

 

[N3BP]

Lance, that is such a great idea! I never even though of that. Thanks for this tip! This will work out good since a speedi-sleeve doesn't exist for the oddball diameter of the crank (2.480'').

Brandon

 

[N3BP]

Slowly getting the tractor back together. New rear main is in. New clutch disk is in. It took me a while, but I finally got the clutch adjusted to my liking by bringing the pressure plate fingers up, which according to the manual I have it set out of spec. The pedal has a nice short throw now. Unlike before it caught at the end of the pedal travel.