Rear Diff Noise

[skn]

Got under the car today to start replacing rear diff.

Tried to undo prop shaft bolts and noticed I could turn it with some difficulty whilst the front wheels remain stationary...

So, looks like I may not only have a rear diff issue, but also my AWD is only partially working as drive from the transfer box is not locked to front wheels as it should be.

Next job, remove transfer box and check splined sleeve etc.

Just as well I love the car:-)

[skn]

Removed transfer box, checked splined sleeve- partially stripped/ worn. Thankfully gearbox output shaft/ transfer box input shaft look ok with all the wear on sleeve.

Here is a pic of the 3/8 rachet I used to get to the awkward top bolt attaching transfer box to gearbox.

Many thanks to the great guide on here for removal

[skn]

Replaced the splined sleeve using the Volvo kit.

Also fitted new gasket to turbo oil drain pipe as had started to weep.

Fabricated a new power steering oil cooler out of Stainless 12mm pipe as the alloy one had a temporary repair done.

Whilst underneath noticed that intercooler looks like it has blown at the bottom with a distorted/ twisted fin that is blowing a fine mist of oil all over the place:-(
Ordered a new one off eBay £90 delivered 2 year warranty:-)

Off to Huddersfield tomorrow to a get a good second hand diff as my droning is still present...

[skn]

Picked up 'good' second-hand diff.

Renewed driveshaft oil seals, filled with correct oil (diff / AOC).

Took it for a test drive and it sounds like Chewbacca:-(

Actually a lot worse than the one I had which only had a mild droning at 40mph.

This one is that bad you can feel the vibration through the floor at 30 mph and wouldnt like to take it over 40mph in case it actually blows up.

[Ducklakeview]

Originally Posted by skn

Picked up 'good' second-hand diff.

Renewed driveshaft oil seals, filled with correct oil (diff / AOC).

Took it for a test drive and it sounds like Chewbacca:-(

Actually a lot worse than the one I had which only had a mild droning at 40mph.

This one is that bad you can feel the vibration through the floor at 30 mph and wouldnt like to take it over 40mph in case it actually blows up.

Have you checked the output shaft bearing on the transfer box?

Can't say I've heard of a single case of rear diff failure, as they are so unstressed..

Mike

[skn]

Mike- yes checked this when I had the transfer box off to do the splined sleeve, was perfect, zero detectable play and rotated smoothly.

Apparently rear diff issues are quite common, although the AOC / DEM units are more problematic than the rear diff itself.

[skn]

Just to finish this thread off in case anyone else has a similair problem...

My original rear diff has worn crown pinion bearings. After stripping the diff and careful inspection you can actually feel the bearings are 'notchy' and rough by rotating the crown pinion by hand.

I have fitted a good 2nd hand diff for now but intend to make some tools to replace the bearing arrangement on the crown pinion at a later date so I have a spare.

The driveshaft carrier bearings are SKF 32008X which are readily available. The crown pinion ones are hidden at the moment by a very tricky to remove 12 point locking nut on the splined shaft which is also recessed in the diff housing. Will require a fabricated long socket and something to lock the splined shaft to undo.