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Triumph TR6 - Opening a differential?

It took over a month, but I finally got the diff off the car - the rusty mount had me under there for more hours than I care to admit. Finally got it off by cutting back enough rubber (not easy with the diff still in place!) to get a pair of mole-grips onto the steel sleeve, then turning. Anyway, I am now cleaning up and painting the outside of the diff, and it is obvious that some oil has leaked from the seals at all three flanges, and at the breather. Not worried about the breather, but it seems to me that I could do something about the other leaks. The diff is from a '75 (and from the build up of grime I have no reason to suspect that it has been removed since 1975...), so I think it has a crush washer rather than shims? I read something like that in a warning about not removing something from the diff. Any advice? The Bentley manual makes the side flanges sound fairly straightforward, though the input flange looks a bit more involved.

It looks like I could remove the aluminium back plate without causing any trouble, but I have a horrible image of all the pieces falling out never to go back together... My feeling is that if oil is leaking out then dirt could be leaking in, so I would like to check if I can. I also want to look inside, just because. With the amount still left to do that sounds pretty silly, eh? Should I just accept that the leaking oil is a design feature and move on?

Finally (sorry about another long rambling post...) what oil is recommended for the diff? Do I need the GL4 or would modern oil be better? Redline synthetic? Is that overkill?

Oh wait, one more thing. I start a welding class at the local college tonight. Is there any way I am going to be able to weld the diff mount reinforcements myself or should I try to find someone to do it for me?

Thanks, as always, for any advice.
Alistair
Alistair

Allistair, I never touched the input shaft so can't speak on that, the side flanges I did remove to replace the seal and bearings. As I remember it took several days at 20,000 lbs of pressure to release the inner axle shafts.
Yes take the aluminum back off, drain the foul oil thats in there. You'll find 30 years of gunk that is very satisfying to remove and clean up, you could also drill a drain hole in the bottom of the cast iron housing, tap it and install a plug. Personally I would stick with the oil Triumph recomends. Something about modern oils attacking the bronze parts inside.
After you have finished your welding class you will be more than competent enough to fabricate and weld in
the diff reinforcements. You could also box in the bottom of the rear diff hanger arch. The only place my diff. leaks from is the cotter pin breather hole at the top with all mating surfaces sealed with a good quality silicone sealer.
Good luck, it's a great project.
Chris
Christopher

Chris says it all Alistair.

Lots and lots of pressure to get the flanges off. I did all three and replaced the seals. I opened up the back and drained and cleaned the inside and replaced the oil. Mine leaks at the breather hole as well. I stuck with the original oil as well.

regards
Mike Petryschuk
Michael S. Petryschuk

That is weird. Mine does not leak from the cotter pinned breather hole at all. At least I do not see any oil running down the side of the casing. Yes it is at level with the fill plug.
OE OIL: GL-4 HYPOID 90 weight rated EP. If it says gear oil then it is most likely EP. 1.27 LITERS or for you Alistair, 4.2US PINTS.
When I had my dif out to reinforce the mounting points, I wish I had drilled a hole for a drain plug. The only way of draining it now is to partially remove (just open up) the housing back plate.
Rick
Rick Crawford

Thanks guys

Looks like I will be taking the back off the diff (wasn't I trying to reduce my to-do list?!), but probably better to wait until I have the gasket - don't want an open diff around if I decide to sandblast something...

I don't know how the oil gets out of the breather, but that side of the back plate was oily while the other side was dry, so I think some oil must have made the journey up through that little hole. Maybe the previous owner went round corners very fast...

Speaking of the breather - I read somewhere not to remove the split pin as it is near impossible to get back in - is that just with the diff on the car? Looks like I could just pull it out and push a new one back in. Why do I want to pull it out? Probably because I read not to...

I am also sure I read somewhere that TRF suggested using modern oil in the diff rather than GL4, but if you guys use it then that's good enough for me (and I suppose it is relevant that the diff has lasted for 30+ years with GL4!)

Rick - I think your units are messed up somewhere - I think it is 3.2 silly little US pints (that's 2.5 real pints - I am English, remember!)

Thanks again
Alistair
Alistair

This thread was discussed between 22/01/2007 and 23/01/2007

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