Diff Noise Cured

[Kerry]

For some time I have had a noise which sounded like the planet gears where about to fall out the diff, this only happened on the lightest of throttle.

The diff appeared silent on acceleration or over run.

After stripping the diff, replacing bearings and reshiming the planet gears, and refitting, the noise still remained.

With a helping hand from Derek, and running the car up while on axle stands, I used a sonoscope and listened to the diff only to find the noise was coming from the chassis tubing around the axle, not the diff itself. I desided to remove the prop shaft, and found a tiny amount of play in the rear UJ. The UJ was replaced, prop refitted, and finally the noise had gone. I was surprised how bad the noise and vibration was for such a small amount of play in the UJ, which I could not feel when the prop was in the car when I had previously removed the differential.

[tractor]

It's always the little things that cause the most grief

[Guest 2b cruising]

I've got the same kind of noise on overrun but waiting till I do engine change. New box going in so if it's not the box it will be diff.

New one of those ready too.

[Longboarder]

Does pay to put a squirt of grease in the prop UJ's every year. When did you last do yours? (Er, when did I last grease mine? Hmm.)

 

Nigel

[Guest 2b cruising]

Fully inspected and greased while investigating noise Nigel.

Thanks for your input though.

[Grim]

i have exactly the same issue. I have changed engine, gearbox, propshaft, differential, and cv joints, and the only thing that has changed is the intensity of the vibration and a slight change in the speed at which it occurs. I suspect it is due to propshaft angles being mismatched, causing a cyclic loading on the driveline. Play in different components such as UJs / diff / CVs does allow slack in the drivetrain at low load, so if you remove enough slack you may have removed the symptom, but maybe not the cause.

 

This is all a bit of conjecture as i have not yet fixed it, or been able to think of a straightforward method of measuring it. I was planning on changing the height of the engine mounts, as that's the only thing i think has changed in the approximate time period of the noise appearing.

Edited August 15, 2016 by Grim

[Guest 2b cruising]

Mine is,fine on acceleration and cruising.

Anything ove 65 mph whenever I take my foot off on overrun, it vibrates until it is down to around 50 mph.

No play in diff. No excessive backlash pinion to driveshaft. Diff oil the correct type according to the manual and no shiney bits in the old oil. This is what makes me suspect the fault is in the box.z

Edited August 15, 2016 by 2b cruising