Offroad-Express

89 safari with factory diff lock. Heard a rumble in right rear axle, spun wheel and bearing felt a little rumbly . Replaced bearing. Noise still there. Only there at 50-55 km's . No noise at any other speed. Put truck on stands and had it going. Noise/vibration appears to be being tramsmitted through axles to wheels . Diff could be source of noise. Dropped diff oil, nothing spectacular, no steal bits at all.
Any ideas before i pull the bitch apart over xmas I can get a hold of another 4.1 diff assembly easy enough. Your thoughts are most welcome as it has got me completely stumped at this stage before I pull it apart. Diff was only apart six months ago and all was good then. Got centrakl trip in mid January, don't want it shitting itself coming down Whitcombe rd.
Al

I reckon it's a uni joint in the driveshaft!

albundy wrote:I reckon it's a uni joint in the driveshaft!

They're virtually brand new, i'd suspect pinion bearings

You only replaced one didn't you Tim. Pinion bearing was looked at 6 months ago and all was good then.
Al

albundy wrote:You only replaced one didn't you Tim. Pinion bearing was looked at 6 months ago and all was good then.
Al

Both were done al

F***

just sent you a pm al, no worries if you need one.

Thought it may have been a loose pinion flange nut, but tight as and no movement in shaft what so ever. Drove the pig into work today as I need to take for a warrant, noise was only just audible..... now I am really starting to get confused. best bet I think is to pull diff out, and eyeball it just for peace of mind.
Al

If it is that quiet Al you may find an eyeballing won't be enough. Diff head bearings can be a real carnt to sus out.
Remember the old rules dad gave you? If it's got wheels or tits, it will be nothing but trouble

Noise hasn't disappeared . Put the pig up on axle stands, had motor running with rear axle in gear. Ear to diff, definite rumble in diff. Pulled it out, seems there is a bit of play/slap in pinion onto crown wheel. Everything else looks like brand new. Even those locker gear repairs I had done still look brand new after two years. Off to shop Tueday morning.
Al

Diff came apart today, suspicion was over tight pinion bearing. Bearing shims looked as if they had been bitten into which would explain why when it was spun by hand to be biting into something. New shims and did the "old paste on the crown wheel test" and pinion was sitting too close on the drive side, castor was perfect, which explains why only felt problem in drive. We tried everything, so have bit the bullet, new bearings tomorrow even though they look and feel perfect, may be slightly out of shape which eye can't see.
Now to rebuild with the new crawler gear transfer case.
al

Diff all fixed, bearings replaced. Took a little time and pinion in, out, in, out, in , out etc to get it just right. Rick at 4wd is like that. Said he never wanted to see my diff again yeah, right