TC40D Rear End repair

[kharman]

Hello all,

I have a TC40D that appears to have the spider gears or other differential parts go bad. The tractor will not back up but skips with a differential clunky noise--4WD / front end still keeps the tractor moving. Goes forward but gets the differential clunky noise when turning.

Today I drained the hydrolic fluid (strained through mesh and have lots of metal shavings), pulled the small bottom plate off and the main pinion gear looks fine.

Raised the rear end and manual spun the tires--no clunking or noticable stripped spots.

So I dug in deeper and pulled the rear wheels--unbolted a bunch of stuff so I could pull off the axle housing to get to the rear end guts to see what needs to be replaced.

However with everything unbolted I cannot get the axle or axle housing to to release from the rear housing--what am I missing?

 

[Laneman]

You really need to get a manual for a repair this complex. There will be backlash shimming procedures to do, and you will need the manual

 

[jinman]

Laneman is right on target. This is just the first of many surprises you'll find before getting your differential and axles repaired. You cannot pull the axle without removing the whole axle housing assembly so you can get to the inner seal and axle retainer clip. Get a manual or get some knowledgeable help there to guide you. This is not going to have a good outcome without one/both of those.

Also, did you change gear ranges and still get the clunking? Your problem sounds like a problem in the transmission to me instead of the differential/axle. I think you'll have to split the tractor at the gear portion of the transmission (rear transmission) to find this problem. Of course, I don't know for sure, but I would before tearing into my own tractor.

Despite the fact that you've "jumped the gun" in my opinion, I hope you find your problem and get it fixed.

 

[kharman]

Good feedback...(manual being purchased in the next few clicks).

The clunking occurs in all ranges and most prevalent in a turn which is why I have focused on the rear end differentials. Plus the front wheels continue to drive when the rear end clunks / lurches and otherwise refuses to drive.

Once the machine began acting up I only drove far enough to get out of the field, get the brush hog and FEL off...and then some trouble shoot jaunts.

I do have the whole axle assembly housing unbolted, I've come this far I might as well have a peek. Last evening I applied some persuasion in attempt to get the gasket to release but did not go "hog wild" until I did a little research (ask you guys).

Will the axle assembly housing release once it is unbolted and I break it free from the gasket?

I wanted to make sure I did not need to unassembled the ROPS, fuel tank, lots of sheet metal, seat and stuff to get into the top of the rear transmission first.

However what I am hearing is the problems may very well be in the rear transmission and I assume I'll need to strip the back half of the tractor down anyway.

I will take pictures and post what I find, thank you for the assistance so far and any other guidance yet to follow.

Warm regards,

Kent

 

[djradz]

I believe that other than all those nuts on the studs and bolts holding both the left and/or right housing on, there is nothing else. I do seem to recall when I pulled my old Ford/NH 1720 rear axle housing that it had to come off very straight. Can't recall but maybe there was a splined shaft in there or something that required removal without it getting crooked, so pulling somewhat equally was required. Not sure, but maybe I lightly pounded (rubber or wooden mallet) on the back side of the stub axle/wheel-mounting plate to start if free, but then somehow pried without damaging the housing mating surfaces.

 

[kharman]

Thank you, I'll proceed and keep you posted.

The new service manual is on its way so in the future maybe I can more help than hinder.

 

[kharman]

Yep, it popped right off once I broke the gasket tight loose. The top 3" stud had to be backed out otherwise the ROPS was going to have to come off.

Good news everything looks fine...bad news I still don't know what is wrong.

I dropped the FWD transmission cover and no problems in there either.

Would anybody suggest I pull the other axle housing?

 

[jinman]

It sounds like you are up to your armpits in this job. I hope you discover your click/tick source soon. Of course, the differential is in the center assy and requires some other disassy. to get at the differential. The Repair Manual says that the hydraulic PTO clutch and shafts must be removed. To do this, you must separate the differential housing from the transmission. I suppose you'll be able to look down inside the differential if you remove the hydraulic lift assy on top of it. So, if you haven't done it yet, you'll have to remove the fenders and the fuel tank to get the hydraulic lift assy off. I'm thinking you'll end up lifting the operator's platform too. There's just a ton of stuff to do that has nothing to do with your differential, but at least you'll be able to inspect those parts and the rest of the transmission.

Sometimes a gear tooth can be cracked and it will tick loudly. I've had them drive me nuts on a standard shift auto transmission. When I was a kid, I replaced both 1st gear and 2nd gear in a standard transmission before discovering a cracked cluster gear tooth. I hope yours is a lot simpler to find. I know this not much fun.

I'll also warn you that there are special tools for installing axle seals. I hope you get your manuals soon and can spend some quality time going over the job.:thumbsup:

 

[kharman]

Thank you all.

From what I am reading the problem resides in one of the hardest spots on the tractor to get to. I will wait for my service manuals and do a thorough paper recon before digging deeper.

Thank you Jim I know you have spent considerable time in the manuals already for me

The issue I am trying to locate is the loss of rear axle reverse (front axle still has reverse and will move the tractor). While going forward in a turn the rear axle also loudly clunks and lurches like the differential is locked but only worse.

I will post my findings and the ultimate fix once resolved so the next guy can get right to it.

 

[jinman]

As you've guessed by your symptoms, the power takeoff for the front axle is driven by a gear on the front section of the pinion shaft before the bevel gear that drives the ring gear in the rear differential. Not having power to the rear wheels during reverse certainly points to the differential as well as the clunks when you turn. I'm guessing that you will find the pinon and ring gear fine, but locate the problem inside your differential gear case or maybe loose bolts that hold that gear case together. As you said, it's the most hard to reach part of the rear axle differential case. At least you are mentally prepared for the level you'll have to go to find the problem.