<VV> Differential setup

[Hugo Miller]

You think that's bad? I'm changing the crown wheel and pinion (ring & 
pinion) on a Jaguar XKE. Changing from a 3.54 US spec ratio to a (hard 
to find) 2.88. The only problem is that the carrier is different - in a 
nutshell, the flange that the crown wheel mounts to is in a different 
place on the 2.88 diff, and that's the bit I don't have, and of course 
they are unobtainable. I've been machining bits off the carrier in the 
hope that I can make it all go together without weakening it.
The pinion has to be set to a certain depth from the diff bearings and 
is marked, in my case +.003", to indicate how much the standard depth of 
2.625" has to be altered. But there is no adjustment for the main diff 
bearings. You just have to squeeze the whole lot into the axle casing to 
give a 0.006" preload, which is achieved by shimming the main bearings 
out from the diff carrier. So you end up pulling the bearings off & 
pressing them back on half a dozen times, then you have to wallop the 
whole lot into the axle casing as it has to squeeze in there to give a 
preload of .006" when fully home. There is a 'spreader' you can use - 
it's like a medieval torture instrument, and it effectively makes the 
hole bigger so you can get the diff into the casing. But if you spread 
it by more than .015" you can crack the axle casing (and there is no 
easy way of measuring .015").
It's a Salisbury axle, almost identical to a Dana 44.
But the one thing I can't get in the UK is that yellow paste for 
checking the gear mesh. All I have is engineers blue, and that is pretty 
useless for this task.
Are you saying you used Rustoleum oil paint? That sounds ingenious!

On 2020-05-08 21:55, Smitty via VirtualVairs wrote:
> Recognizing that way under 1% of you are ever going to tackle
> rebuilding a differential, this is for the few that will.  I have
> rebuilt several before that worked out well so I was surprised that I
> couldn’t get a good tooth contact pattern after installing new seals
> and bearings.  Using the revised pattern supplied by Mike Dawson was
> no help either.  Time after time the pattern suggested thinner shim
> behind the rear pinion bearing.  My own logic went along with that 
> but
> after getting down to no shim at all I knew the problem was 
> elsewhere.
> I had been fooled before by thinking the stator shaft was fully
> seated into its bore along with the bearing race so I had been extra
> careful when installing it.  I.t had gone in smoothly and come to a
> good solid stop.  I was very reluctant to believe it was not all the
> way in.  On my 11 th diff disassembly I placed a large steel block on
> the floor with a short section of pipe the diameter to match the
> machined boss around the stator shaft..  stood the case up on top of
> that, and with a 18 inch brass punch, proceeded to whale on the edge
> of the bearing race with a 3/4 pound hammer.  Did it move?  I sure
> hoped so.  Hard to tell as I was only looking for a few thousandths 
> of
> an inch.  Put it all together with a factory shim, and set it up and 
> I
> had an acceptable tooth contact pattern.  Why am I waiting all this?
> Just hoping tp save some other poor schmuck from going through what I
> have been through.
> BTW, I talked to several about what they used to paint the gear tooth
> for a reading.  Some had a wild and exotic formula to recommend.  i
> used Rustoleum.  White would be ideal.  I used light gray because it
> is what I had.  It worked very well.
> Sent from my iPad
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