Folks,
Here is the diff housing from my 1989 A+ gearbox.
I'm a bit concerned about this crack - or what appears to be a crack.
It doesn't go full depth, so not causing an oil leak.

Could this just be a factory fault, or cracking caused by the nearby gearshift rod? Other alloy parts from this gearbox do seem to lack the quality of finish found on the earlier assemblies.....



Opinions gratefully accepted.

On a similar matter, did A+ boxes get diff bolts (3/8") rather than studs? Mine currently has bolts fitted. Does it even matter?

Thanks.
Matt

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'68 Deluxe w/Metro engine

yeah looks like a casting imperfection line to me

& yes the later A+ boxes had bolts for both the diff & the primary case too

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

Thanks Matt, good help thanks.
Should I be using gaskets on that housing, or as I understand, just silastic as per factory?
I've got a new tube of Copper RTV which seems to be a good choice.
Matt

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'68 Deluxe w/Metro engine

I'd use Loctite 515 master gasket, and no gaskets top & bottom on an A+ box.
You can bin the sidecover gaskets too if using this stuff. As I did on both my boxes. Saved a heap of diff shims, as these damn black gaskets are too thick now.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I've seen many diff caps with those lines and while they look worry-some, I've not had any give any trouble.

Not all were gasket-less. There is no hard and fast rule that you can go by to check which type you have. The factory recommends at the pre-assembly stage, putting the diff cap on and measuring the bearing tunnel for roundness without gaskets and then check with gaskets.

When it does come time for assembly, if it is a gasketless type, do a complete trial dry assembly first and work out the diff pre-load shims, then do it for real.

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