W124 Auto box whine? Or Diff?

[Phil_H]

Got an annoying whine from the drivetrain on my 250D ('87). Sounds like the Gearbox and goes if you coast in neutral (Only done for diagnoses purposes). The gearbox oil is level and clean.

Any ideas?

cheers
Phil

 

[Aussie Nick]

Sounds like a bit of wear in either Phill. Suggest you try to locate wether it is the diff or the gearbox. If it is not an auto without limited slip diff try some NULON additive.It will improve things all round.

 

[television]

This is the pinion bearing,, say at 30-40MPH when pulling it whines,take your foot off and it stops, that is the pinion bearing in the diff

 

[wireman]

Does it whine in the lower gears? if it does is the pitch of the whine the same or different in lower gears (at the same road speed)?
If its the diff you should be able to play a tune on it by lifting and applying throttle pressure, not always the case but a good indicator.

 

[Aussie Nick]

Its going to be one of these damn problems to locate as its almost impossible to try to trace the sound whilst driving safely. Only sure way I can think of is to jack it up on the hoist with someone in the cab controlling the motor and engaging the gears and someone listening from below moving from the diff to the gear box. However I do not think this is at all safe and would not try it under any circumstances.
You might instead take a couple of people as observers on a test run and have one sitting in the front and the other in the rear to ascertain where the whine seems to be loudest whilst you keep your eyes and attention on the road.

 

[television]

The sound of a pinion bearing is unmistakable

 

[Phil_H]

Well today has been an interesting day...lol (See...broken engine thread)

But think the whine is the diif, as I had the rear seats up in the boot today and the noise was much more noticeable, and as the diff is located more or less under there I'm quyite convinced it is! So do you think is a case of low oil? Or will a rebuild be required?

 

[Parrot of Doom]

Easy enough to check the oil level, to top up just remove the fill plug and put yer oil in.

To change, remove the fill plug and then the drain plug, and again put yer oil in.

Only costs a tenner or so to do this. You need a bit of leverage to get the plugs out though, I used a ring spanner on the allen key to shift it.

 

[Aussie Nick]

Phil Before you do anything expensive try the Nulon additive. I dont know whether you can get it where you are. But would cost about $15.00 here for a tube. It might just save you a whole heap of trouble.

 

[Phil_H]

Thanks...


I'm gonna do the diff oil, and I'll see if I can find some of that Nulon.