Morris Minor Owners Club

afternoon all!

so I've recently come into possession of a 3.9 diff, and was wondering if anyone has any tips / guide on how best to switch out the old 4.2 for the new one? any pitfalls, things to know?

Thanks!

A relatively easy job to do with no pitfalls that I know of.

Has the axle case got the axle filler plug in the rear face of the banjo?

Make sure that you put the halfshafts back in on the same side you took them out of, or you'll end up with them breaking!

yup - filler is on the back of the axle, so will still have a place to top up

anything else I could check whilst I've got it off? checking replacing UJs? Which reminds me - I need to mark the prop shaft with chalk to indicate which side was up don't I?

dudload wrote: ↑Fri May 17, 2019 9:05 am
anything else I could check whilst I've got it off? checking replacing UJs? Which reminds me - I need to mark the prop shaft with chalk to indicate which side was up don't I?

It will be down one half turn later!

Nice easy job using basic tools make sure to tighten the housing up evenly and for the little amount they cost i would get a spare gasket I learned the hard way that tightening the housing unevenly ended braking it and over tightening the bolts lead to a broken gasket nothing worst than waiting another couple days for parts

You normally mark the diff flange and the propshaft flange adjacent to one another before removal but as the diff will be new in relation to the propshaft there is little point in marking either.

If the balance does not feel right after fitting the propshaft it can always be turned on the diff flange by 180 degrees to see if the balance is better and/or any vibration reduced.

The diff assy is secured to the axle casing by studs, nuts & spring washers not bolts - mentioned in case someone queries their diff to axle case fixings.

Care should be taken (as stated above) when tightening the nuts.

Fit new diff gasket which has been lightly greased.

Phil