IRS Differential

[ColoradoCobra289]

I was able to get the differential in tonight with the help of a friend, however, there is a small gap on both the DS and PS rear mounts and a larger gap on the PS front. The PS front appears that the sleeve is preventing the diff from snugging up to the bushing, but the rear just looks like a slight gap - see pictures.

228228

228229


Should I be worried about this gap putting too much stress on the bolts and should I go ahead and get some washers/shims to close this up?

[Grubester]

This has come up before, and others will say just go with it -- maybe they're right...
On my Mk4 build (50% complete), I made washers of a thickness to take up the gap.
With the HP torque that runs through the IRS I just didn't want any unplanned movement or hop.
It was just a judgement call on my part and was no sweat to just do it -- didn't see a downside.
***my bigger issue is with the way the IRS is mounted in the frame such that it dips down at the yoke by 1.5 deg or more and exasperates the driveline alignment. Oh well.

[edwardb]

FFR has stated repeatedly when asked by multiple builders that this isn't a problem. Put a washer in there if you want. But look at how the diff is bolted to the frame. The two mounting bolts at the rear are into an extremely rigid frame member. That plus the overall tight fit isn't going to let the diff move even that small amount. I've never heard it stated, but my guess is this gap is intentional. The diff is already somewhat challenging to tip into place. Probably you've found that out already. Without that amount of clearance (e.g. zero gap) you'd have to push the diff into place with no angle. Which would be very difficult. Even if the diff did move that small amount (which I'm saying isn't possible) the CV axles and slip yoke in the transmission would easily handle.

[ColoradoCobra289]

Thank you for the quick reply gents - I decided to use some washers to mind the gap!