Automatic gearbox service - R129 SL320

[r129MAN]

Advise- my 1998 SL320 has now done 80,000miles, should I consider a service on the auto box such as oil & filter replacement, or is it a so called sealed for life unit. I have owned the car for 5 years and I must admit that the gearbox seems sluggish ie when I first bought the car the there was a punch when you floored it to kickdown, but now although it does change down it does not seem so positive. It might be my imagination and being used to the car. Any thoughts and advice greatly appreciated.

 

[television]

Yes you have the 722.6 box and these were supposed to be sealed for life but this has now changed and the fluid and filter best done every 40k miles now. the cost from an indie is around £140 for this job

 

[Frontstep]

Its not too hard to change the fluid yourself but much easier to let one of the Indie chaps at it.
From Memory MB wanted £250 ?

 

[bigasotonuk]

Hi,
As previously mentioned these gearboxes were "meant" to be sealed for life, but they respond very well to a filter and fluid change, they generally don,t have a Torque Convertor drain plug so drainning all the fluid can be problematic requiring other techniques to ensure a complete oil change. It is also not uncommon for the sump pan bolts to sheer.
There is also an oil seal for the wiring loom coming out of the gearbox that is worth replacing at the same time this part has been superseded and improved many many times, if this seal goes it can allow fluid to wick along along the length of the wiring to the transmission ECU in the car, mine went and when I was wiring some speakers the fluid had pooled on the floor pan on the passenger side, the thick sound proofing under the carpet was soaked in it.
I would expect to pay between £150-175, using genuine MB fluid, filter, sump pan gasket etc. if you were to include the new seal approx £20-30 extra.
The nearest Independant to you I can reccommend is Peter at Pentangle, just off of the M27 J1 at Cadnam.
http://www.pentanglemb.co.uk

 

[television]

Thanks Andy for reminding me of the drain plug, there is a good chance that this car has one as they were not finally deleted till 30-09-99

 

[r129MAN]

Thanks to my query about auto g/box

Thanks to all for your advice especially bigasotonuk, have been using Peter Webb`s services at Pentangle since he stated up ( to all who live near Southampton highly recommended). I will give him a call and get a quote for an oil & filter change.