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MG TD TF 1500 - anyone have a replacement diff cage?

I've been troubleshooting my 4.3 conversion and believe I may have a cracked diff cage. The new bearings were pressed on at a shop with a bearing press. After assembling my rear end, I checked the pinion rotational torque. For 180 degrees of the crown wheel rotation it was exactly what it should be. For the other 180 degrees the rotational torque was twice normal.

I pulled the halves apart and started checking things out. What I found was that the carve rotates not in a circle but in an oval shape. I made a video of it and the link is below. The shop that pressed the bearings is going to review the situation tomorrow (they were brand new when the shop pressed them on).

What are the chances one of you guys has a spare diff cage? I will know more by Wednesday evening.

Alex Waugh

That is the mobile link and you may have trouble getting to the video from there. Try this one out instead:

Alex Waugh

I bought a complete rear end from Dave Clark. He rebuilds them and sells them along with associated parts. He may be able to help you. You can e-mail him at
He is located in Arizona.
Mort Resnicoff (50 TD-Mobius)

Alex, I would try Huge Pite first. He is in Vancouver, BC. Easy day trip for you if he has one. Dave may or my not part with one. He winters in Arizona and heads for Washington in the late maybe he could bring one by. If one doesn't pop up here for you, I have a complete 5.1 rear end I pulled out of the TD sitting in the shop. All new bearings and seals that I don't really want to see go to waste, but if it comes to that I can break it apart and get what you need from it.
L E D LaVerne

Could the bottom bearing be cocked or on crooked? Just wondering.
George Butz

I have a few spares, but I am pretty sure they're from MGAs a midget and an MGB. Don't know if those'd work or not with your ring gear, pinion, spiders, etc. Someone else may know though.

Brian Warmuth

Should be one in the barn if you need it,Alex. Lemme know and I'll check. Dan
Dan Craig

Thanks all...

I'm hoping that it is just an issue with the bearings being on the spindles incorrectly. However, with that long of a shank for them to ride on and the interference fit, I'd be surprised if they could get cocked after being pressed on with a bearing press. It just seems to me that they'd straighten out after they got going. I hope I'm wrong.

The other thing that showed up is that THIS time I had to reduce the shim under the diff cage. The last time I set this rear end up with the 4.3, I had to add 6thou to get it to start registering backlash. Also, everyone I've talked to that does these on a regular basis indicates that they've NEVER had to reduce shimming.

If it is indeed the cocked bearing at 3thou out (as the video shows) then that might be enough cause the difference in shims. My fear is that what is causing the reduction in shimming is a cracked diff cage that has changed physical shape such that it now is "fatter" in width thus inducing the tighter tolerances than before.

The shop that pressed the bearings is supposed to get to looking into it today. I will know more once they have a chance to look it over and check the run out of the cage. Once I know what's going on, I'll check back in.

Thanks all for the offers. I'm hoping for it to be just the bearings!

Alex Waugh

Alex I have seen something like your mishap with the cage in the past ( history almost ). In that case the owner took the casing apart not marking with a punch the two halves matching the mark's . When he put them together again almost the same wobble appeared .

I hope my memory served me well in this.
Gerard Hengeveld


I don't think the cage comes apart in any way. Do you mean the two halves of the axle housing?

Update... Unfortunately the fellow who's doing the work on the bearings is out with a major cold. I'm hoping hell be back on Thursday. Till then, I don't have anything new to report.

Alex Waugh

Alex , I had one of my elderly moments ( again lol ) I pictured a model A case in my mind instead of one from a MG, Sorry,

Gerard Hengeveld

Hi Gerald. That is the way the TC diff carrier comes apart.

R Taras

Hi Alex,

Sorry to hear of your recent problem. I do not have a spare carrier but I might have a source for a complete rear end core in Phoenix.I can check that out if you like.

I'm not convinced you have a cracked carrier. Your method of dialing leaves a lot of room for error in the readings. I assume the bottom bearing is resting on a spacer so that the carrier bearing shaft is not hitting the table. I do the same thing when testing for run-out of the ring gear once it is installed but I do it on the magnetic chuck on my surface grinder so it cannot really move much. Even then I need to be careful how I turn it or I get errors in the readings due to the bearing clearances. On the other hand you seem to have quite a lot of wobble there.

I would have the shop pull the bearings or at least the suspect bearing and inspect for cracks. If they have a way to set it up to dial out the carrier at the bearing shafts that would be good. Since the problem could also be with the bearing if it got damaged on assembly I'd have them press on a new bearing and see if that fixes it.

Dave Clark Arizona


Thanks for your offer on the donor rear end. I have a few people that say they have a "cage only" that is on offer if I need it. The plan is to have the run out on mine checked before I do anything else. I'm hoping to know by the end of this week what is going on with the wobble.

Alex Waugh


So the shop can't find anything wrong with the bearings. The shop that has the cage right now does not have the ability to check the run out of the cage spindles. So, they are going to remove the bearings and then I'm going to take it to a different machine shop and have the run out checked on the spindles. I'm hoping to have a confirmation on Monday night if indeed the spindles are out of shape. I'm looking forward to moving on with this project. It's getting a little crazy to have so many strange issues with an otherwise ordinary job.

Alex Waugh

This thread was discussed between 13/02/2013 and 16/02/2013

MG TD TF 1500 index

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