2005 ML 270 - drivetrain backlash

[mdj8]

Similar to an earlier poster I have an annoying problem with my 25,000 mile 2005 ML 270 (w163) which seems to have a drive train fault. Once warmed up the car "snatches" when gently accelerating and decelerating in slow moving traffic. This is accompanied by a clunk underneath the car when gently speeding up and another when realeasing the accelerator and slowing down. It feels as though something heavy is sliding backwards and forwards. Sometimes the effect is very pronounced, particularly at higher speeds when slowing down for and then accelerating onto a roundabout for example. The same noise/feeling although more muted can also be heard when stationary and shifting between drive and reverse - it is more harsh when going from reverse to drive. I previously owned a 2003 ML350 and never experienced anything remotely like this. The car is under warranty but after 3 visits (can't be replicated, need a technician etc) my MB dealer insists it happens on some W163's and mine is one of the better ones - read I should put up with it. I feel they just dont want to get their hands dirty. Has anyone else had this experience and reported it to MB UK? If so I would be grateful for any pointers as to how the issue was fixed or resolved. Many thanks.

 

[television]

Hello and welcome to the forum, the fault you describe is in keeping with monetary loss of drive in the gearbox, and no it should not do it.

We do have a good man on the forum Psmart who owns one and had several.

Lets hope that he sees your post

 

[psmart]

Thanks Malcolm, but Im only an enthusiast; Ive gone quite red!!!

mdj8, two issues I see here, 1 is that the accelerator cable is 'sticky' which may be more apparent on the 270 than the petrol models. Oigle highlighted this and his fix is a permanent cure, but Panason1c found a mod which works quite well, where you remove the spring on the accelerator potentiometer on the bulk head/firewall. This reduces the snatchiness.

The clunk could be down to the famous engine/gearbox mountings. Mine was clunky this last year until I got down and changed the mountings and now the car is almost perfect (its done 71k). Trouble is, dealers dont seem too enthralled to change engine mountings, there have been a number of posts on this issue recently.

Hopefully its the above two issues combined, otherwise drivetrain problems spring to mind! There are quite a few v.good people on-board who may come up with further possibilities.

 

[mdj8]

Thanks Malcolm and psmart. Indeed a sticky accelerator cable did compound the problem but that was changed on the first visit - the cable is now reasonably smooth. Also on the first visit an electrical plug into the gearbox was found to be leaking, initially fairly severely but as I asked more about it and potential problems I got the "not significant enough to do any damage". Anyway I was told the lack of ATF fluid could also be a contributor and that it may get better once topped up. Quite frankly there was no difference. My feeling is that it could be loose gearbox mounts, propshaft mounts or even UJ's if they have those. My real problem is how to get the dealer to acknowledge it is not normal - the service mgr says two techs have told him its within spec. When I told him my previous ML 350- did not have this issue he said he had an answer for that - some do and some dont - how do I confirm that all shouldn't. Many thanks, Matthew. P.S. liked the "monetary loss of drive" - presume that an MB term which is unfixable.

 

[television]

Momentary loss of drive = torque converter or Bad gearbox ECU or intermittent control module on the gearshift or EIS system intermittent

The only real way is to drive the car with a real time analyzer to discount many parts

I would try another dealer, make sure that they are not part of the same outfit

 

[mdj8]

Thanks Malcolm. Further to psmarts post I searched on engine mountings and believe that may be the direction to head toward. Until reviewing those posts I thought the tingling vibration I felt at certain rev ranges through the steering wheel and accelerator pedal were just because the car has a diesel engine (I prefer petrol - quiet, smooth etc). Anyway the vibration is more noticeable at speed and I actually thought something may be touching the steering rack that shouldn't. - This may all tie in. I'll talk to the dealer as the car is there now and see whether they can test for that.

 

[psmart]

I used to own a Jeep Grand Cherokee and from new, as gears engaged, the drive train would 'clunk'. I owned a Sierra 4x4 sometime before which also did this, so it seemed like 4x4 take-up/tolerances of the drive train. The ML didnt have this and apart from the snatchiness at low speed which the cable fix cured, has been clunk free until the last year. The replacement of the mountings has reduced this by say 80%, but it has a small 'clunk' still.

On the Jeep I remember that engaging the AirCon exacerbated the clunk.

Could it be that your car has not had 1 careful owner who might have thrashed it, therefore causing excessive wear on the drive chain - hence as power is engaged a clunk is felt? Just a thought.

The leaking electrical connector - Panason1c pointed this out, but Im suprised at 2 years old you have the problem. Mine was in its 5th year before it was noticed, albeit a slight gearbox fault was noticed the year before and rectified by addition of ATF. Nb. Panason1c mentioned it had been re-designed so on a 2005 would have thought you would have the new connector in-place from new.

The gearbox mount when I replaced it was hardly damaged/compressed, but the engine mounts were in a bad state - not broken 100% but none the less bad. There are two props from the mid-center of the car to the front and rear axle housings. If you get under the car, remove the mid protection cover (you have 3, one at the front of the engine, 1 directly under it and 1 covering the gearbox) you can see the props in the Transfer case and can judge accordingly if there worn/damaged. You can also see the gearbox mount which is basically mounted onto a cross-member (2 bolts in either side of car) and 1 bolt holding the mounting onto the cross-member and 2 into the gearbox. If youve got the patience and time, look yourself so you have a good idea whats going on.

 

[mdj8]

Thanks psmart. Back in 91, I owned a Shogun v6 - didn't do this, 1997 a Nissan terrano 2 - didn't do this, 2001 a Hyundai Terracan - didn't do this, 2003 ML 350- didn't do this 2005 Range Rover - did do this but fixed. Due to some sort of torsion bar bushes at the back which were worn. For this car I am the second owner but I dont think the first's driving would be the cause - it feels to me like a component has gone wrong. Even if it has been thrashed it's an auto so the engine/drivetrain would be protected and the car is built to go offroad and tow heavy things so I doubt anyone could wear it out sufficiently in 25000 miles of road driving. Reluctant to start crawling under the car just yet as I paid over 20K for it purely because of the manufacturers warranty until June 2008. Instead I have just been on the phone to cust services at Daimler Chrysler UK H/O. They will now follow up with the dealer and we will see what happens from here - The dealers statement that "the clunk is normal for an ML 270 and its worse in some than in others" is what I shall be leveraging to get them to fix the car. Either all ML 270's should have such a characteristic or not - modern manufacturing methods and quality control would not allow otherwise. Thanks and Rgds

 

[panason1c]

bdj8,
My ML (which has covered over 100k miles) clunks only 'mildly' when i take up/release the drive......

There are a total of six drive shafts, two differentials and a transfer box on a ML so some backlash has to be expected....however.....your description of a distinct 'clunk' sounds to me that a thorough inspection of your driveshaft uj's, differential backlash tolerences, engine/gearbox mountings, etc is required.

Regarding the 'snatch' issue.....mine was the same as yours and also with a brand new ML in my local dealers showroom......my solution was to remove one of the accelerater return springs .....the one fitted to the potentiometer under the bonnet (against the bulkhead).....dont worry, there are still two return springs remaining, one on the pedal itself and the other is built into the potentiometer........3 years later and still a nice smooth pedal action (albeit slightly lighter)

Good luck.

 

[mdj8]

Thanks Panason1c, however the prob is definitely not the throttle cable. I have already had that fixed and as of now the accelerator is relatively smooth. Per above the clunk can be heard when stationary with the footbrake depressed and then shifting between drive and reverse - no accelerator involved. Pushing the engine mounts as likely suspects in the meantime will let the board know what transpires. Rgds

 

[psmart]

A test on the engine mounts is cranking the engine when cold. If it fires into life with a thud, then the engine mounts arent doing there job, when the engine fires, should be sweet and effortless.

The Grand Cherokee had the clunk with 0 miles on it, hence not considering it a fault! Just goes to show.... albeit, it was a manual not an auto and even slipping the clutch you still got the problem!

Why didnt you hold onto the 350 and get a Merc Service Plus contract?

 

[mdj8]

Thanks psmart. Reason for not keeping the ML 350 was that I was living in Hong Kong at the time where an ML is regarded more as a people carrier than offroader. Over here with a diesel at least I feel I'm doing something for the environment, whilst also having a need for four wheel drive as I live in the country. I actually considered a Cayenne S but couldn't come to terms with sub 15mpg or parking one in Tesco's car park in these anti 4x4 times. - Oh and the Cayennes I tested did not clunk at all - silky smooth 6 speed and a rather nice exhaust note from the V8.

 

[Hibbo]

You could do the good ol' backlash test of jacking one wheel up at a time and turning it by hand (parking brake off and 'box in P). This will reveal any lash in the drivetrain.

PS. Maybe you've bought one that someone has abused by taking it (heaven forbid) OFF-ROAD!

 

[psmart]

You could do the good ol' backlash test of jacking one wheel up at a time and turning it by hand (parking brake off and 'box in P). This will reveal any lash in the drivetrain.

PS. Maybe you've bought one that someone has abused by taking it (heaven forbid) OFF-ROAD!

Now now Hibbo.... I had a go at you and all the other enviromentally unfriendly polluters in the Auto-Box thread.... leave off us 4x4ers or kick that inefficient auto-box out of your car and take a sledgehammer to that air-conditioner as a starter......... most of us 4x4ers are quite enviromentally aware

 

[Hibbo]

Now now Hibbo.... I had a go at you and all the other enviromentally unfriendly polluters in the Auto-Box thread.... leave off us 4x4ers or kick that inefficient auto-box out of your car and take a sledgehammer to that air-conditioner as a starter......... most of us 4x4ers are quite enviromentally aware

I can't quite see how taking a sledgehammer to an airconditioner could in any way be seen as environmentally friendly! Shall I take a hacksaw to the pipes on the back of my fridge too? :wink: :lol:

PS. How did you know I had aircon???:-o

 

[kebo57]

Hi mdj8
how long have you had this problem
how many miles with and with out the problem
what do you think brought this on
is it getting worse

Kevin

 

[mdj8]

Thanks Hibbo but the cars at the dealer at the moment having it's steering column replaced because it made a graunching noise when on full lock. I doubt it's been off road and I probably won't do so either as I don't want to get the carpet dirty. If I were to go off road I'd get something decent like a Suzuki sj or Daihatsu fourtrak.... Apart from that when you jack up one wheel you're bound to have slack, how much there is vs how much there should be could only be measured by experience/comparison with another and I don't have the necessary info. As far as I can make out my car should not make a thump when I go from reverse to drive and should no "catch up with itself" when I slow down and then speed up.

Kevin, the problem was there when I bought the car and surprise surprise became more apparent on my way home from Mercedes where it had just been serviced. As mentioned earlier I wasn't too concerned because of the warranty but that presumed I would receive an appropriate level of customer care. It's not getting worse, you just tend to notice it more as you become more annoyed with the Mercedes garage doing whatever they can to avoid resolving it and getting you to accept it. Rgds

 

[kebo57]

Kevin, the problem was there when I bought the car and surprise surprise became more apparent on my way home from Mercedes where it had just been serviced. As mentioned earlier I wasn't too concerned because of the warranty but that presumed I would receive an appropriate level of customer care. It's not getting worse, you just tend to notice it more as you become more annoyed with the Mercedes garage doing whatever they can to avoid resolving it and getting you to accept it. Rgds

mdj8 I have had drive train problems with my ML 270 they were relating to the front prop shaft all though I didn't no this till it manifested from a twittering noise to the front prop all most sheering off over some 1000 miles http://forums.mercedesclub.org.uk/showthread.php?t=23992
From what you say I don’t think that your problem lies with front prop as there is vibration associated to this, probably same for the back prop as well
You could try driving another one to compare, where are you, drive mine if you won’t
Kevin

 

[wscheffer]

Worn Universal Joints

I would have the universal joints checked as Panason1c said. The clunking sound from drive to reverse is a common indicator that there is play in the joint. Also some of the noise could be that the center sleeves in your prop shaft could use a good greasing. They should contain about 6 grams of grease.

Hope this helps! :mrgreen:

 

[kebo57]

I would have the universal joints checked as Panason1c said. The clunking sound from drive to reverse is a common indicator that there is play in the joint. Also some of the noise could be that the center sleeves in your prop shaft could use a good greasing. They should contain about 6 grams of grease.

Hope this helps! :mrgreen:

Not so with the front prop the hardy spicers on my front prop where still serviceable after all most destruction of the joint
There was now rotational backlash associated with my problem
Also how could I grease prop shaft joint
Kevin