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Differential Rebuild

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Hi All,

Anybody read the chidren's book "If You Give a Mouse a Cookie"? I removed the differential from my TR4A IRS to replace the broken rear mount, and while I'm at it the rubber bushings. But then it seemed like replacing the leaky seals in the diff would be a good idea... and maybe the cover gasket, too. So I removed the cover, and there, sitting in the puddle of 90wt in the bottom, was about 80% of one of the pinion gear teeth. Darn. I can get a used one for $300, but what am I getting? TRF's CAR Components wants $1300 for a rebuild! But that's a virtually new unit. What to do??

At least I now know what that clunk in the rear was...

Joel
 
That's a good idea, Bob. I can't believe I forgot about John - he did my transmission and o/d a couple of years ago! And thanks for the offer, Andy..


Joel
 
Rebuild it yourself!

It's basically the same unit I did for my Stag a couple of years ago. Little tedious getting all the shims right, but it turned out well (once I realized it was actually the diff from a 2.5 Estate :laugh: )

Never did get around to writing an article about it, but you can get some idea from the photos at https://s258.photobucket.com/albums/hh260/TR3driver/Stag%20diff/

Note that the big pry bars & a scrap of wood make an acceptable substituted for the mysterious "case spreader". Also while the magic "pinion depth setting tool" would no doubt make things easier, it's not required. If the contact pattern is good, then things are in the right place.
 
Could be time for a Infinity rear diff.
 
Southern Maine to Albany, NY, ain't that far away. Maybe 4.5 hrs? I was down to Cincinnati a couple weekends ago, about 6hrs away, picking up Spitfire body panels. Sounds like a good excuse for a road trip to me.
 
Wait! You're in the middle of the same exercise in which I find myself.

But tell me: Is it the front or the rear mount which is broken? Virtually everyone says it's the front mount that breaks, not the rear mount.

Do you have pics of the broken mount? Can you describe your planned fix?

I'm having a buddy weld gussets onto to both the front and rear diff mount bridges per Roger Williams' book, and using substantially the same kit that "the big three" offer and sell.

I'm also likely to order axles from GoodParts and I'll be reinstalling a Nissan R200 LSD Differential with the GoodParts Kit.

I toyed with the idea of buying a rebuilt standard TR4A Diff from Rimmer, TRF or others, but since the PO installed the R200 I'll stay with that.

Good luck--but I'd really like to know more about that rear mount that broke.

thx
 
I've got a used TR6 differential that I paid $125 for about two years ago just before these things started getting silly money. I'm in south eastern MA and I'll sell it for what I paid for it. Probably a two hour drive for you.

I think that it would probably need seals, but the rest seemed fine. 3.70 ratio.
 
you should get GP better CV joint drive shafts if you plan on purchasing new commplete units, very quite, nice looking components and very easy to install

Hondo
 
And of course there is the T/A stud replacement project, "while you are in there" and on and on it goes.
 
Thanks all for offers and suggestions. Decided to send John Esposito the business, and I'm back on the road, but if I'd seen your post, Paul, I would've jumped on it. Oh well. I like to keep things as "showroom" as possible, so no substitutions for me... The studs were solid, so I left them alone. Ya gotta stop somewhere.
KVH, the part that broke was the cast aluminum bracket that bolts to the rear of the differential proper - the one the big rubber doughnuts hold onto. Dunno why it broke. It's a different part on the TR4A-IRS than the TR6. One of the "ears" simply broke off.
 
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