Diff noises

[disco_nex]

Gsay Ladies and Gents,

I am just looking for some previous experience on a problem. On accelerating from a stop with a light-medium to heavy boot of the accelerating pedal, the rear diff seems to be making a noise. It kinda sounds like a thump-thump-thump noise. With this, you can feel it as well. The oil level is good, and I don't see any other issues that may be causing the issue. There is no water ingress.

The diff gears were replaced 50 000 km, and the clutch packs about 30 000 km. The oil has not been changed since the clutch pack replacement. Would this be the first port of call, or could it be something more sinister?

Thanks

[rastus2571]

Originally Posted by disco_nex

Gsay Ladies and Gents,

I am just looking for some previous experience on a problem. On accelerating from a stop with a light-medium to heavy boot of the accelerating pedal, the rear diff seems to be making a noise. It kinda sounds like a thump-thump-thump noise. With this, you can feel it as well. The oil level is good, and I don't see any other issues that may be causing the issue. There is no water ingress.

The diff gears were replaced 50 000 km, and the clutch packs about 30 000 km. The oil has not been changed since the clutch pack replacement. Would this be the first port of call, or could it be something more sinister?

Thanks

Have you checked your rear gearbox mount for sagging as the tranny case could be sitting on the bash plate? Common problem. Sounds like someone under the car with a hammer.

[HemiJeep]

Get somewhere nice and quiet and listen to your thump thump thump, maybe along side a concrete wall or in a tunnel if you have one handy?
Check for the timing of your noise - does it match tyre rotation or lots quicker (uni's travel at 31/2 times the speed of the wheel, but they might only be noisy in one plane) Wobble your uni joints / tailshaft maybe?
Check leaf and shackle bushes they could be shot and causing a 'tramp' action or even shocky tops might be rowdy - common in bar pin type shocks.
Google bar pin eliminator for info. May be a cheap fix, about 20 bucks a set.
These may be quiet on low rev take-offs, but otherwise rowdy. Rough roads would be loud too though....

Good luck.

[HemiJeep]

Tranny case bash plate ! Of course. Forget diff try that first. (Face - palm)
It's only a couple of bolts - whip it off and go for a drive. Simple.

[disco_nex]

Thanks for the replies. I forgot to mention. The noise only lasts for 1-2 seconds at most when accelerating from start. It certainly is not the bash plate (I had enough problems with that many years ago when a certain 4WD company fitted my lift kit). I will check the ideas HemiJeep gave me on the way to work tomorrow.

Thanks for the advice!