Mercedes E300 Diesel Gearbox probs

[PaulWales]

Hi Folks, i am entirelty new here and trying to find my way around this site I recently bought a 1994 E300 diesel car with 191K on the clock, it's ok. HOwever i have a query.....The gearbox seems slow to respond at times, From 1st to 2nd there can be a 'bump' and it's uncomfortable when i drive the car. Going through to 3rd and 4th is sound though it seems to change quick now and again. Secondly when i turn the engine off it runs for a second? Is this timing or familiar troubles? Thanks for your help in advance!! Paul

 

[television]

Hello Paul and welcome to the forum. You have a nice car there, re the box,do check that the vacuum pipes are not leaking as this can give hard changes , also do have tha fluid and the filter changed, everyone reports back with smoother changes

 

[Bolide]

Engine not shutting off points to a vacuum leak. Vacuum also controls gearshifts...

Hard 1-2 shifts when cold are quite common with this engine & box and flared 2-3 or 3-4 shifts are also common. All shifts being very hard is a vacuum pipe off under the inlet manifold

The system has to start with the correct amount of vacuum and this vacuum is then modulated to change the way the box works. So an incorrect base setting or an air leak will play havoc. Also look for blocked pipes

Nick Froome
www.w124.co.uk

 

[PaulWales]

Thats absolutely brilliant thanks for the technical advice. I thought the gearbox was broken but the guy's at mercedes said they should last longer but 'bring it in'. They might be good but i am sure i can find a specialist here on Tyneside. I will check the car over and get back to you. Cheers. Paul

 

[Bolide]

At that mileage thumps & bumps when changing gear are exacerbated by

* worn engine mounts
* worn gearbox mounts
* knackered propshaft doughnuts
* worn diff bushes
* worn rear suspension arms

If you have any of these in addition to a gearbox control problem the effect will be magnified

Nick Froome
www.w124.co.uk

 

[kth286]

Paul

Do you know that unlike petrol engines there is no natural vacuum produced by a diesel engine.

It has to be generated by a vacuum pump, so that is the first place to check out - is the pump generating full vacuum.

 

[harpoonlouis]

Me too

First post ever but it is a tale of woe!

I had the same symptoms on my newly aquired 300E Estate bought to tow the horse box.

Unfortunately yesterday the little thump in the gear box turned into a rather larger thump and a sheared rear drive shaft! Get those pipes checked as that continual thumping may have been the cause of my half shaft becoming two quarter shafts!

Anyone know of a reputable breakers who may have a shaft assembly? £512 plus VAT from MB Ouch!

 

[Bolide]

Almost every breaker will have these. Start with Mercman in Southampton

Nick Froome
www.w124.co.uk

 

[television]

First post ever but it is a tale of woe!

I had the same symptoms on my newly aquired 300E Estate bought to tow the horse box.

Unfortunately yesterday the little thump in the gear box turned into a rather larger thump and a sheared rear drive shaft! Get those pipes checked as that continual thumping may have been the cause of my half shaft becoming two quarter shafts!

Anyone know of a reputable breakers who may have a shaft assembly? £512 plus VAT from MB Ouch!

Hello and welcome this is the diagram of the vac system on the box
http://www.detali.ru/cat/oem_mb2.as...++717.412&CT=GA&cat=08R&SID=27&SGR=195&SGN=09

 

[harpoonlouis]

Thanks for the diagrams, will get those checked out.

I have a part search in with Mercman, let's hope the morning post ( email) brings some good. news!

John

 

[PaulWales]

The information is great. Sadly i know that Haynes don't do a w124 manual for '93 (my year) onwards. I know it is the newer diesel model but i am sure there is little difference in contrast to my parents old 300 d from 1987! I must have a look to sort out the problem of the gear change it's very uncomfortable like you're being shunted particularly if i need to get out of a junction quickly. It changes smoother pulling away and going down hill. I am quite DIY handy and can do basic repairs but i need to have a look for these hoses you are talking about and change the gearbox oil and filter. I have a w124 manual from haynes i wonder if that would help me out? thanks paul

 

[Bolide]

The later diesel engines cars (606 multivalve engine) are very different wrt the engine & box. The manual won't be relevant

As a rule of thumb, if the box shifts hard 1-2 when cold, forget about it. If it shifts hard 1-2 all the time, and other shifts are OK, you may be able to help it with adjustment of the vacuum pressures and/or replacement of the modulator. If all shifts are really hard you have a vacuum pipe off the inlet manifold

Nick Froome
www.w124.co.uk

 

[beemerjay]

though it seems to change quick now and again.

Check for stricky rear callipers, I've just sorted this on an e 300D W210 series clucnked like made whn cahnging when cold and gradually the callipers freed up and so did th egearchange, the clus ? Do you have to rev her to get her to move or just release the brake???

Secondly when i turn the engine off it runs for a second? Is this timing or familiar troubles? Thanks for your help in advance!! Paul

Hmnm as mentioned before Vacuum Probs or the little shut off diapraghm has perished a bit?