Mercedes W210 (E300 TD) Gearbox Thump!

[rjsdavis]

Well guys - yet another small problem to tax me, with this lemon of a car that I appear to have bought....

She has recently started "thumping" on occasions. She only does it badly when she is cold, and it usually occurs in the first few miles of driving. Most typically is when you slow down to say 10 miles per hour to drift over a road hump, and when you go for the throttle again - she thumps, and it feels as though another car has tapped you up the rear!

The other times that she does it is if you have to brake sharply from a reasonable speed (around 40mph +), and then re-throttle quickly to gather speed again - this results in the biggest thump - and this feels like someone has properly whacked the car in the rear.

You can tell when it's going to happen.... If you brake from speed (like coming upto a roundabout), you can feel when the car has changed down to a lower gear, anticipating you pull away again and re-gather speed. If you re-throttle before it has come down to 2nd gear - woe betide you and you get a large thump... If you pause for a second, and let it come out of the high gear - no problem at all. There is NEVER a problem changing up a gear though.....

It has been suggested that the gearbox oil level is too low, and this is the cause of the thumping - does this sound right?

Thanks again for those kind enough to reply.

Richard

 

[mioba]

Well guys - yet another small problem to tax me, with this lemon of a car that I appear to have bought....

She has recently started "thumping" on occasions. She only does it badly when she is cold, and it usually occurs in the first few miles of driving. Most typically is when you slow down to say 10 miles per hour to drift over a road hump, and when you go for the throttle again - she thumps, and it feels as though another car has tapped you up the rear!

The other times that she does it is if you have to brake sharply from a reasonable speed (around 40mph +), and then re-throttle quickly to gather speed again - this results in the biggest thump - and this feels like someone has properly whacked the car in the rear.

You can tell when it's going to happen.... If you brake from speed (like coming upto a roundabout), you can feel when the car has changed down to a lower gear, anticipating you pull away again and re-gather speed. If you re-throttle before it has come down to 2nd gear - woe betide you and you get a large thump... If you pause for a second, and let it come out of the high gear - no problem at all. There is NEVER a problem changing up a gear though.....

It has been suggested that the gearbox oil level is too low, and this is the cause of the thumping - does this sound right?

Thanks again for those kind enough to reply.

Richard

mountings possibly

 

[Parrot of Doom]

Check the propshaft and diff. Take it to an indie, get in on the ramps, and have them go over it.

It may well be a minor problem that the previous owner was scared of fixing. Mine had quite a few, it was quite cheap to fix them all (apart from the welded glow plug, grrr...)

 

[pcman_jh]

My 1999 E300 thump...

...was the bush on the driver's side read hub assembly. The bush that joins the bottom of the wheel hub to the wishbone assembly. It was totally shot!

The only real way of seeing it with your own eyes was to jack up the car and using a crow bar to apply lateral movement to the assembly.

The bush cost around £20 and while it was a DIY repair, it did take a few hours to get the hub free from the car to start hammering the old bush out and the new one in, but no more thumping!

PS - Mine just passed an MOT weeks before. Suspect the guy who sold me the car knew the guy doing the MOT as it should never have passed...

Hope this helps.

 

[rjsdavis]

Check the propshaft and diff. Take it to an indie, get in on the ramps, and have them go over it.

It may well be a minor problem that the previous owner was scared of fixing. Mine had quite a few, it was quite cheap to fix them all (apart from the welded glow plug, grrr...)

Dear Parrot

Thanks again for this reply - very helpful

I've got my mobile mechanic coming over next Monday to look at this and the duovalve (heater) problem..... When thinking about this specifically, is there anything other than;

1 - gearbox mountings
2 - insufficient oil in the gearbox
3 - a shot "doughnut"

that could be the causes of my gearbox thump?

Whilst I know he is a good and trustworthy mechanic - I like to be able to give him as much info as possible, so he can minimise the diagosis time and crack straight on with the repair.

Once again - your help is very much appreciated.

Richard

 

[Parrot of Doom]

If there was insufficent ATF in the gearbox, it wouldn't want to change gear, and would slip all the time.

A thump would suggest to me that some part of the transmission thats designed to take up some of the stress on the transmission when you press the accerator is faulty. Could be anything really, even something as daft as loose wheel bolts or faulty engine mounts? Does the car shake when you turn the engine off?

 

[rjsdavis]

If there was insufficent ATF in the gearbox, it wouldn't want to change gear, and would slip all the time.

A thump would suggest to me that some part of the transmission thats designed to take up some of the stress on the transmission when you press the accerator is faulty. Could be anything really, even something as daft as loose wheel bolts or faulty engine mounts? Does the car shake when you turn the engine off?

Thanks again for the reply.

The engine mounts were just replaced two months ago and are brand new.... she had the typical shakes in park and in reverse, which were cured at a stroke with the new mounts. The guy I bought them from in the USA was surprised that I wasn't replacing the gearbox mounts at the same time?!?!

Furthermore, this thump is only after braking and / or decelerating for speed bumps. It never happens at any other time......

It mainly happens when you pull up reasonably sharply at a junction, or behind someone that has stopped unexpectedly.... The size of the thump appears to directly correlate to the sharpness of the braking... in fact I had reason to emergency stop just yesterday for the first time in ages, and the car felt like the gearbox was going to fall off!

If you draw up nice and gently and under control - then there is no noise or thump at all!!!

When you slow down to drift over a speed bump at say 15 miles per hour - if you throttle down too quickly, she will again give you a little thump, but if you are light and slow on the throttle she won't - she's very temperamental indeed.......

Richard

 

[Uncle Benz]

...was the bush on the driver's side read hub assembly. The bush that joins the bottom of the wheel hub to the wishbone assembly. It was totally shot!

The only real way of seeing it with your own eyes was to jack up the car and using a crow bar to apply lateral movement to the assembly.

The bush cost around £20 and while it was a DIY repair, it did take a few hours to get the hub free from the car to start hammering the old bush out and the new one in, but no more thumping!

PS - Mine just passed an MOT weeks before. Suspect the guy who sold me the car knew the guy doing the MOT as it should never have passed...

Hope this helps.

In defence of the MOT man - the standard MOT pit jack will not reach the sill mounted jacking points on most Mercedes. This leaves the MOT man with 2 options:

1. Jack the rear of the car up on the rear diff. You often see them do this, but it places excessive load on the rubber diff mountings which are not designed to support the load of the car in that way. A sympathetic MOT man will not do this as he knows it is wrong.

2. Jack the car up on the lower suspension arms. This is a kinder method to the car, but places the suspension in compression, which hides any play in the very joint that you mention.

It is a difficult one to call, but another classic case of the MOT being difficult to administer thoroughly on all cars. The general MOT inspector does not have the marque experience (or lack thereof) of a main dealer; he does not even have the experience of a specialist independent. He has to assess the safety of all cars, and a degree of generalisation is inevitable.For example, they will never see the potentially lethal corrosion that can occur in the front subframe of W210 E class, since they are forbidden to remove plastic undertrays.

 

[rjsdavis]

Thanks again for the reply.

The engine mounts were just replaced two months ago and are brand new.... she had the typical shakes in park and in reverse, which were cured at a stroke with the new mounts. The guy I bought them from in the USA was surprised that I wasn't replacing the gearbox mounts at the same time?!?!

Furthermore, this thump is only after braking and / or decelerating for speed bumps. It never happens at any other time......

It mainly happens when you pull up reasonably sharply at a junction, or behind someone that has stopped unexpectedly.... The size of the thump appears to directly correlate to the sharpness of the braking... in fact I had reason to emergency stop just yesterday for the first time in ages, and the car felt like the gearbox was going to fall off!

If you draw up nice and gently and under control - then there is no noise or thump at all!!!

When you slow down to drift over a speed bump at say 15 miles per hour - if you throttle down too quickly, she will again give you a little thump, but if you are light and slow on the throttle she won't - she's very temperamental indeed.......

Richard

Problem appears to be diagnosed - moby mechanic is telling me that the gearbox mount is split and knackered - which makes sense, as it was one of the things I was expecting it to be...... it also ties up with the fact that the harsher the braking - the harsher the thump!!!

Anyway - at least we've got to the bottom of that little mystery! Only really got to sort my internal heating to get ontop of actually driving a car that works properly!!!!

 

[rjsdavis]

New gearbox mount has been fitted - slightly better - but STILL GOT MY GEARBOX THUMP!!! Grrrrr..........

Any ideas???

 

[Parrot of Doom]

I don't think its a gearbox thump. Its a transmission thump (yes I know the gearbox is on the transmission). I still think its propshaft/diff related.

 

[rjsdavis]

I don't think its a gearbox thump. Its a transmission thump (yes I know the gearbox is on the transmission). I still think its propshaft/diff related.

Moby mechanic is back on Thursday to put on new anti-roll bar bushes (hoping that this will cure my squeaking suspension) - Jesus this car is a lemon!

I will let you know what we find.......

 

[Blobcat]

Moby mechanic is back on Thursday to put on new anti-roll bar bushes (hoping that this will cure my squeaking suspension) - Jesus this car is a lemon!

I will let you know what we find.......

I don't see how you can call the car a lemon. All the issues you have listed look like normal wear and tear in a 6 yr old 127,000 mile car.

 

[Bolide]

Is the thump when the gearbox shifts gear?

AFAIK the early E300 W210s are the same in this respect as the late W124s

There's a pneumatic system that links the engine & box to smooth out changes. If the pipe from the inlet manifold comes adrift it'll bang shifts instead of flaring them slightly. If that's the case go looking for bad pneumatic pipes or connections


Nick Froome
www.w124.co.uk

 

[rjsdavis]

I don't see how you can call the car a lemon. All the issues you have listed look like normal wear and tear in a 6 yr old 127,000 mile car.

Not a lemon eh?

* Complete new exhaust (inc Cat)
* New wiper linkage
* New balljoints
* New link arms
* New anti-roll bar bushes
* New heater control panel
* New duovalve
* New compressor
* Re-gas and poss leak of condensor
* Squeaking suspension - yet to be diagnosed (probably top arms)
* Gearbox thump - yet to fully diagnosed
* Power steering rack leak
* Cylinder slap from Cyl No 3
* Air bubble in fuel system
* Recent leak from fuel injector pump (fixed)
* Drivers seat won't stay fully upright where I leave it (drops back slowly over time)
* Bulbs consistently blow (Particularly brake / and rear side lamps
* Electric windows regularly freeze (OPEN) whilst driving and requires a restart to clear the fault
* Cruise control works intermittently (stops working for a couple of days and then comes back all on its own)
* New windscreen
* Still not heating the car as it should and air-con not working
* Rusting around the rear boot catch

And that's all I can think of off the top of my head at the moment.....

Want to buy it? Make me a good offer....... ;-)

 

[rjsdavis]

Is the thump when the gearbox shifts gear?

AFAIK the early E300 W210s are the same in this respect as the late W124s

There's a pneumatic system that links the engine & box to smooth out changes. If the pipe from the inlet manifold comes adrift it'll bang shifts instead of flaring them slightly. If that's the case go looking for bad pneumatic pipes or connections


Nick Froome
www.w124.co.uk

Nick

THanks alot for the reply. However, this is not where it happens......

It never bangs shifts going forwards and accelerating. It only happens during braking, and coming to a complete or near complete stop. If I brake hard to pull up - the thump will get louder. The harder the braking - the bigger and louder the thump. I would note recently that the effect is far less pronounced when the car is warm - and the most severe thumps only occur when the car is cold and under braking....

If I slow to drift over a speed hump - if I am too quick to get back on the throttle after having cleared the road hump - I get another thump - these are the only times that it happens.

Moby mechanic has recently (2 weeks ago) changed the gearbox mount - but this made NO difference at all. We're going to try adding a litre of ATF to the gearbox to see if this improves it, as another possible is insufficient ATF.

He has checked the propshaft and doughnut, and reckons that these look fine and don't need to be changed or touched. So still trying to work out this most annoying of problems. For the moment, as long as I drive as if I was chauffering someone (ie really smoothly) - then she's fine, and it barely happens at all - crank it up slightly, and I soon regret it.

 

[television]

If you have checked the vacuam as Nick (Bolide) suggest, then it is worth checking the final drive and components.

By jacking the car one side (hand bake off, in p ok) by turng the wheel backwards and forwards you can see how much play you have final drive, by do this quite hard you could here the clonk and find the offending component.

Malcolm

 

[rjsdavis]

If you have checked the vacuam as Nick (Bolide) suggest, then it is worth checking the final drive and components.

By jacking the car one side (hand bake off, in p ok) by turng the wheel backwards and forwards you can see how much play you have final drive, by do this quite hard you could here the clonk and find the offending component.

Malcolm

Malcolm

Thanks everso for your help.....

I appreciate the contribution. I will of course pass on your comments to my moby mechanic - but it doesn't make a lot of sense to me! I presume you mean turning one of the car wheels backwards and forwards - ifso, which one? Presumably a rear "drive" wheel?

However, if the car is in Park - shouldn't there not be any movement at all? I would really appreciate a little bit more info on what you driving towards finding with this test......

 

[television]

Malcolm

Thanks everso for your help.....

I appreciate the contribution. I will of course pass on your comments to my moby mechanic - but it doesn't make a lot of sense to me! I presume you mean turning one of the car wheels backwards and forwards - ifso, which one? Presumably a rear "drive" wheel?

However, if the car is in Park - shouldn't there not be any movement at all? I would really appreciate a little bit more info on what you driving towards finding with this test......

Yes the rear wheels, in park,with one one the ground, the other wheel will turn, when the rotation reverses any clonks can be heard and backlash in the system can be seen. The propshaft may rise up and down in the center. The main components here are,propshaft UJ'sand surpports, pinion bearing and half shafts, its the standard way to check. I just do not think that the fault is gearbox related.

Malcolm

 

[Parrot of Doom]

Not a lemon eh?

* Complete new exhaust (inc Cat) - normal
* New wiper linkage - normal (failure to lubricate)
* New balljoints - normal
* New link arms - normal
* New anti-roll bar bushes - normal
* New heater control panel - could have been repaired tbh
* New duovalve - unlucky
* New compressor - possible lack of use?
* Re-gas and poss leak of condensor - possible lack of use?
* Squeaking suspension - yet to be diagnosed (probably top arms)
* Gearbox thump - yet to fully diagnosed
* Power steering rack leak - unlucky
* Cylinder slap from Cyl No 3
* Air bubble in fuel system - normal
* Recent leak from fuel injector pump (fixed) - normal
* Drivers seat won't stay fully upright where I leave it (drops back slowly over time) - probably minor adjustment
* Bulbs consistently blow (Particularly brake / and rear side lamps) - easily rectified
* Electric windows regularly freeze (OPEN) whilst driving and requires a restart to clear the fault
* Cruise control works intermittently (stops working for a couple of days and then comes back all on its own) - probably a dry joint
* New windscreen - normal (mine needs one due to high motorway use)
* Still not heating the car as it should and air-con not working
* Rusting around the rear boot catch - normal

And that's all I can think of off the top of my head at the moment.....

Want to buy it? Make me a good offer....... ;-)

I'd say most of the faults are niggles - I know because I've had similar. You've been unlucky with the aircon but I wouldn't mind betting that the previous owner never used it - this kills lots of AC systems, not just Mercs. This is what I've done in a year of ownership:

oil change & filters
top up PAS fluid
balance rear wheels
buy tools for boot
front ball joints
drop links
leaking coolant pipe
5 new glow plugs
replace diesel spill pipe
replace both fuel filters
2 new front tyres
new shocker for belt tensioner
replace atf, filter and gasket
replace faulty driver's dimming mirror
new belt tensioner and pulley, new belt
new front pads and sensors
new wheel bearing
repair front foglamp
repair headlamp levelling mechanism
repair gearbox W/S switch
2 new rear tyres
lubricated wiper mechanism
new spring for belt tensioner
new spring for throttle position sensor
new key
new rubber feet for ABS box
new charcoal cabin filter
new front exhaust including cat
new bulbs for heater panel
2 new front discs
full laser geometry alignment
clean intake manifold and egr valve
fix fuel leak on shutoff valve
replace fuel pipes as necessary

and coming up:

2 new engine mounts
refill diff and check breather





So believe me mate, you're not doing bad


PS - Do not add any ATF until you know the current level by dipping it. Too much ATF = major problems. If the level is slow, the box will be slipping, not banging.