1998-E280 -W210 Auto box fault

[NormanB]

This is on behalf of a friend honest!

He has a 1998 E280 Auto with 145K miles.

It has developed what he believes is an Autobox problem. He has taken it to an independent who checked the fluid level and told him it would be around £1600 for a new box - no tests, no road tests nothing!

The symptom is he can be driving at a steady speed say 30 or 50mph (whatever) and the engine revs will rise without input from him. He eases off the throttle and it all seems to steady down - for a while -the behaviour is fairly random (and in fact has not done it at all in the last week).

He asked my advice - and I know fa about these boxes so I told him not to get his chequebook out just yet and I would ask the experts!

BTW it has never had the transmission fluid changed. Is it worth having the 'codes' read - is that likely to reveal anything useful?

 

[Dieselman]

Check the fluid level. If that's ok a change wouldn't go amis but it sounds like a clutch might be slipping.
a slipping clutch could be a result of a sticking hydraulic valve so a fluid change would possibly fix that, otherwise it could be the valve body or torque converter.

Draining the fluid and analysing the debris could tell the story. If there are lots of metal particles and clutch material then it's bad news.

 

[NormanB]

Thanks that does not sound too hopeful then - I will pass on the advice.

 

[Parrot of Doom]

http://www.autogearbox.co.uk/

I've heard good things about them, they might do an exchange unit if it comes to the worst. Should be cheaper than £1600 anyway!

 

[PJH]

The Indy garage that I use told me last year that Mercedes have reviewed the service routine for 5 speed autos, so called SEALED FOR LIFE units.
They now recommend oil changes for these 'boxes, same as for the 4 speed units.

 

[DrNick]

Having seen a technician top my box up I can confirm that in no way are they sealed for life (electronic 5 speed 99 vintage)
There is a pipe in the engine bay near the back with a platic cap on. If you remove this you can pour oil down the pipe into the gearbox. If you have the dipstick you poke it in here to get a level reading. (Best to do this before pouring any oil in!)
They might be filled for life, but thats different from being sealed for life. The technician I spoke to would recommend a basic drain and fill every 24K, given that its impossible to drain all the oil out. Change a bit every so often was the philosophy. Its a bit at odds with other advice reported here, but makes a certain amount of sense.

 

[NormanB]

Is it really impossible to drain these modern auto boxes?

I though it was a 3 stage process, torque convertor, box and then remove the transmission sump cover thingy to get at the filter.

 

[Dieselman]

Is it really impossible to drain these modern auto boxes?

I though it was a 3 stage process, torque convertor, box and then remove the transmission sump cover thingy to get at the filter.

Assuming there is a drain plug on the torque converter. Some have one, some dont.

 

[big x]

Having seen a technician top my box up I can confirm that in no way are they sealed for life (electronic 5 speed 99 vintage)
There is a pipe in the engine bay near the back with a platic cap on. If you remove this you can pour oil down the pipe into the gearbox. If you have the dipstick you poke it in here to get a level reading. (Best to do this before pouring any oil in!)
They might be filled for life, but thats different from being sealed for life. The technician I spoke to would recommend a basic drain and fill every 24K, given that its impossible to drain all the oil out. Change a bit every so often was the philosophy. Its a bit at odds with other advice reported here, but makes a certain amount of sense.

In fact there is a machine that connects to the feed and return gearbox oil cooler pipes.Every last drop of oil is pumped out.MB have been using them since the torque converter drain plugs where discontinued in the late 90's.
The rest of us do indeed use the part drain principle.
adam