Oil leak from diff/drive shaft

[bryan]

Do all minis and 1100s leak oil via the diff/driveshaft seals when left standing for a few weeks?
I’ve replaced the seals on the 1300 GT, but it still leaks , and am now planning to replace the bronze plain bearing in the flange.
I wondered whether you experts think that is likely to fix it or whether it’s a lost cause .
Thanks

[Peter Laidler]

To be honest Brian, assuming that the bearings you mention are the originals, I'd have replaced them at the same time as the oil seals. Can we assume that the bearing surfaces of the outputss were perfect? I'm certainly no expert except that I'll be doing mine shortly. And I'll be doing the seals and bushes while it's apart.

[mk1]

If the back of the dif housing is the correct one and rhecbearingsxandxsealsxare good. They shouldn't leak oil.

[bryan]

That’s good advice, thank you.
I’ll have a look at the surfaces of the output yokes when I replace the bearings and if they’re ok I’ll bung it all back together filled with optimism!

[1071bob]

If you change the side cover bushes you'll have to get them machined or reamed to the correct bore to suit the output flange diameter.

[CooperTune]

Over the years I had collected 60 yoke/pot side covers. Seemed a good idea to rebush them. I paid someone to remove the seals, press bushing out, clean, dip in paint striper, glass bead, wire brush and press bush in place. Bolting covers to diff housing I align honed using king pin hone in Sunnen rod machine. Flipping, stroking and checking with dial bore gauge .001 to .0015 clearance being target. My figures were $65 parts and labor each. I have used up about half and none leak so far. A fixture for milling or lathe would make a short run easier. I have a bucket with HS covers, bushes are more and I don't have enough for a run. Steve (CTR)

[bryan]

Aaaaargh.
Didn't realise they'd need to be reamed.
The 10 minutes each I’d allocated to do each side may need revision then

['S'-type]

Guessworks supplies re-con ones with new seal and bush reamed to size ready to go at £42 ea. Not sure if that's exchange.

Minispares also has them £48

Seems a lot when the bush and seal are less than a fiver but if you can't do them accurately yourself you don't have a choice.

Don't know what the cost would be to get a shop to do the work.

[Peter Laidler]

Machining the bshes in a lathe is simplicity itself It is making the jig to hold them square is the killer.......

Using a replacement cover is all very well - if you've got a selection of shims to shim-u the inner bearing against the replacement cover which ain't necessarily going to be the same as the one you've removed

On the othe hand, you could simply machine the bush to the inner i/dia. before you press it in

[CooperTune]

My first try at rebushing side covers, I tried to do them one at a time using a short piston pin hone for a big diesel. Once done it was clear they were not in line with each other. By the time I honed enough to allow the out puts to turn they were worse than the worn ones. And yes, they did leak. I failed to mention we also measured the step on the gasket side. For the most part they were the same. A few had the step machined, most likely form old race boxes. A few were cracked or had other damage. I think it would be nice if the bushes were like cam bearings. If pre sized to allow for press fit crush, press and fit would be nice. As we know the new pot joint ones have the tab. While they work fine, they don't look 100%. Steve (CTR)

[bryan]

I think I’ll take the easy way out and buy the casing with the new bushes fitted and reamed. Life’s too short.
Ah, and remember to tighten up the casing only after pushing the yolk into its bush a la fitting of timing chain case .