Diff carrier fit

[Billelan]

Hi. I’m just reassembling my differential and notice the iron housing if a very sloppy fit in the aluminium carrier. I reckon there’s around 1mm clearance between the spigot on the cast housing and the bore of the aluminium carrier. Nothing appears to be worn. I suppose fitting the drive shaft before tightening the 8 set screws will tend to centralise things.
Is this normal or am I missing something?
Thanks Bill

[jono]

The plain shank on the bolts should centralise everything, no?

[Billelan]

Hi Jono. To some degree they will, however, they’re not fit bolts so will also have clearance. I would have expected either good spigot location or a couple of dowels.

[jono]

Hi Bill,

I see what you mean

I recently rebuilt my diff onto a better housing and to be honest never really considered 'fit' of the diff to the housing, I was more bothered about gasket thickness for similar reasons.

I seem to recall I did what you suggest and offered it up 'loose' then fitted the outputs and new bearings prior to nipping it all up and that seemed to work fine.

Cheers

Jon

[Billelan]

Thanks Jon, that’s what I’ll do. I tend to overthink things these days.
Cheers
Bill

[promotor]

Hi. I’m just reassembling my differential and notice the iron housing if a very sloppy fit in the aluminium carrier. I reckon there’s around 1mm clearance between the spigot on the cast housing and the bore of the aluminium carrier. Nothing appears to be worn. I suppose fitting the drive shaft before tightening the 8 set screws will tend to centralise things.
Is this normal or am I missing something?
Thanks Bill

They're not a great fit but it's not too much of a worry.
I did see one case with two dowels utilising the two dummy holes in the final drive casing which had non-genuine corresponding holes in the diff casing - I believe the diff came from an old racer, perhaps even a 26R which would make sense.

As a test, try fitting 8 bolts (or even studs) to the casing and offer the diff up to it to see how much wiggle room there is.