Thread: diff noise

Originally Posted by harry

has anyone any experience with noisy diffs and how to cure it?
i have a series 1 disco with an arb locker in the rear,
recently i had her on jacks and ran the car in gear to sort a vibration,
although i think i know where the vibration is,[front pinion bearing - another time]
i noticed the read diff makes a lot of noise.
so i pulled it out and reset the backlash to book figures 004"-007" tho, mine's at 006", which i thought would be ok for a diff of her age, bearings are good, teeth are good, and never noticed a diff noise on the road,
anyway put it all back together ran it jacked up and still makes noise, driving only on load, back off and ok.
doesn't seem loud when driving, but now i know its there, i am not happy.
any clues?

Did you check what the tooth contact pattern was like after you adjusted the backlash? Could be the reason for the noise.

As for the front pinion bearings, I would get onto that straight away, as it will cause your crown wheel and pinion to wear out of alignment, and cause it to become noisy.

the noise wont be helped by the pinion bearing being out of spec but more than likely its tooth noise from it not sitting properly.

Originally Posted by cmurray

Did you check what the tooth contact pattern was like after you adjusted the backlash? Could be the reason for the noise.

As for the front pinion bearings, I would get onto that straight away, as it will cause your crown wheel and pinion to wear out of alignment, and cause it to become noisy.

How hard is that bearing to replace as mine is on its way out


Adam

Originally Posted by agrojnr

How hard is that bearing to replace as mine is on its way out

It's a diff out job, as the pinion bearings are a pair of tapered roller bearings. Get a workshop manual, and follow it, as you need to setup preload on the pinion and carrier bearings, also check the tooth contact pattern, as you may need to change the pinion height to get it correct, and just to make life difficult, I don't think that is covered in the workshop manual. There is a bit involved to get it right. I've rebuilt the front diff on my 80", as it doesn't do that many miles (clocked up 2000 in the last 4 years!) but I get my 90's done professionally, as if it is not done correctly, it is easier to break the crown wheel and pinion, and they will also wear incorrectly and become noisy.

a diff rebuild isnt rocket science but its not something you can "yeah that feels bout right to me" fix and expect it to last.

a good DTI + base is essential as is bearing blue and an accurate spring gauge to gauge the preloads.

Originally Posted by harry

has anyone any experience with noisy diffs and how to cure it?
i have a series 1 disco with an arb locker in the rear,
recently i had her on jacks and ran the car in gear to sort a vibration,
although i think i know where the vibration is,[front pinion bearing - another time]
i noticed the read diff makes a lot of noise.
so i pulled it out and reset the backlash to book figures 004"-007" tho, mine's at 006", which i thought would be ok for a diff of her age, bearings are good, teeth are good, and never noticed a diff noise on the road,
anyway put it all back together ran it jacked up and still makes noise, driving only on load, back off and ok.
doesn't seem loud when driving, but now i know its there, i am not happy.
any clues?

Pull the diff centre out and take it to a Diff Specailist and get him to set it up for you, if you haven't the experience or the tools, this is the ONLY way to go if you want your diff to last and be quiet, Regards Frank.

ok thanks for those comments, both diffs will be out tomorrow or sat, picking up new bearings from ricks tomorrow for the front, and gotta find the bearing blue in the shed somewhere.

You need a machined dolly to go between the carrier bearings and machined "known" spacers so you can slip the feeler gauges in to get pinion height

Just keep in mind with old diffs, they're best set up how they were as when they've worn a patch, if you correct it they may sing at you forever more, just because a diff is noisy doesn't mean that it will fail