Transmission noise

[nevilledoreen]

I have a 1993 r129, 300sl when the auto gearbox changes from first to second gear I can hear a whurring or bumpf for about 3 seconds.this noise also happens when I am in top gear and put my foot on and off the gas .
The noise only occurs when the engine is at medium revs if I push the car or drive it slowly it does not occur on the gear change or top gear.
I have had the gear box checked and the front rubber drive doughnut replaced.
The noise appears to coming from the rear of the car not the gearbox.
Has anyone had this problem before or could you give me any idea what it is?
Neville

 

[nevilledoreen]

Come on Fellas someone must have had a similar problem ANY IDEAS.
Neville

 

[E270 Owner]

Sounds like bearing over/under run on the diff.

Mercedes 500SL R129 rear differential fluid change - YouTube

 

[nevilledoreen]

E270 Thanks for your reply what makes you think it is the diff oil?
Have you had this problem ?
Regards
Neville

 

[merc85]

Ive had a noisey diff on a 1988 420se, and 2.6 190e, does sound similar to what you are describing

 

[Vlad]

The diff seals can leak on these, so check the oil level in the diff and top up if required.

 

[nevilledoreen]

Thanks for the reply Vlad I checked the oil level is OK and quality Good
Neville

 

[E270 Owner]

Differential Service

• Check condition of rear axle rubber boot & clamps
• Drain all old fluid from rear axle housing while it is still hot
• Inspect old fluid condition before disposal
• Refill with Mercedes-Benz approved fluid
• Recommended after every 12,000 mile interval

Problem is if its noisy it will need most likely overhauling if the service intervals were not met.












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