190E help!! Where is my backlash coming from?

[drainaudio]

Hi all,
Still trying to solve the slight bit of intermittent diff backlash I'm having.
George Fraser have gone through the driveline and say it's all good, they also say the diff is good. I however can't believe a backlash that has an audible metallic clunk to it is how MB designed this car.
I don't have any vibration in the driveline or diff/gearbox noise other that what I would consider normal compared to other cars.
The 190E will be changing smooth as pie up and down through the gears whether being driven soft or hard and then sudddely "clunk" diff backlash!! :Oops: What I have discovered 2day and maybe this sheds some light on the problem is the follwing: Level surface change from Park to D or R smooth no problem as you would expect. If the nose is pointing downhill and I change from Park to D, no problem but form Park to R there is an audible mettalic clunk and the car jumps a little. Same thing happens in the opposite situation Park to D if the nose is pointing uphill.
Would this not suggest some sort of play somewhere in the driveline?
Any help would be appreciated this is starting to drive me crazy!!
Thanks, Geoff.

 

[stwat]

They are the exact same symptoms i have!!!!! Very anoying they are too.

Stu

 

[mike65]

I doubt this is the solution but it might be worth checking anyway. At the back of the throttle body is a vacume, with a pipe on autos which connects to the autobox regulator. If its not plumbed in correctly or has a leak then changes will be clunky.

Mike.

 

[paulcallender]

Two pronged approach:

1) Check gearbox oil level and idle speed, which would affect the 'shunt' as the drive is taken up. All autos shunt a little, this is normal.

2) Check other components on the underside, eg exhaust system, suspension. Grip it hard and give it a really good wiggle.

Its possible that everything is within spec, its just that since its all worn to near its limit, then there is more shunt than a new car. In which case, you could fix it, but you'd have to change everything.....

 

[Bolide]

W201 driveline shunt

I believe the W201 is similar to the W124 in this respect. On older / higher mileage cars this will always be a problem and I think it's a combination of autobox wear, worn rear suspension bushes & arms, worn prop doughnuts, worn diff, worn diff mounts, slack engine mounts and slack gearbox mounts

If you replace all of these you should be OK!

If it passes the critical eye of George Fraser then I'd say it's probably as good as it's going to get without building a "new" car as above

Is it possible your expectation of the car is unreasonable?


Nick Froome
www.w124.co.uk

 

[drainaudio]

Hi..
I'm not sure I'd describe my expectation of the car as unreasonable..
It only has 96k on the clock, has been well maintained all it's life and it's a Mercedes after all. I've had cars by GM and Ford that had much higher milages and never sufferered from a driveline that would just randomly have this clunky behaviour. One minute the car is smooth as pie then randomly it will shift with a clunk - I would have thought if it was a case of wear and tear that these symptoms would be evident all the time. Is it possible that items such as the propshaft donuts could appear ok but actually be worn and need replacing? The gearbox and diff are very quiet when operating, so oil levels and general wear of these components seems ok. When I get this clunk either whilst driving or shifting into gear there is a distinct metallic sound to the clunk and it feels as though slack is being taken up somewhere.
Any ideas would be great, thanks, Geoff.

 

[paulcallender]

The propshaft rubber joints would have to become quite worn, before giving a noticeable 'clunk' in the drivetrain. This would be visible. Since its been checked over by George Fraser, then maybe the next thing would be to have them drive it too, and comment on the faults you perceive. They would be able to tell if there is a problem here, having experience of many Mercs. Remember, these are RWD compared to FWD offerings from later model Ford/Vauxhall.

 

[drainaudio]

Hi..
I think I will have to go down the route of driving the car with one of George Frasers mechanics to isolate this problem. We did this previously and instantly it was a case of "yes I see what you mean" and problem solved. I think GF are a great company and very on the ball when it comes to service and having a genuine regard for their customers. The only problem with this is it means they are always extremely busy and I have had occasion where they forgot to do something simply because they were so rushed off their feet. In regards to making comparisons with the Merc and other vehicles, please give me a little credit here.. I'm acutely aware of the different between rear wheel drive and front wheel drive vehicles and it would be foolish to compare the driving characteristics of the two. So for the record, American GM and Ford cars, all rear wheel drive, no intermittent diff backlash - mostly built like rubbish and a feel bordering somewhere between cheap and generic :sad:. Hence the purchase of a "mint' 190E, for a daily driver it's the only car I really like at the moment, not wanting a newish Merc or Audi as it has to live parked on the street in London a lot of the time. Minor problems aside it is a great car and will be perfect once these issues are sorted - has really given me the Merc bug - I'm now on the lookout for a "mint" SL500 or SL320 that I hope to acquire before next summer.
Cheers, Geoff.

 

[paulcallender]

In regards to making comparisons with the Merc and other vehicles, please give me a little credit here.. I'm acutely aware of the different between rear wheel drive and front wheel drive vehicles and it would be foolish to compare the driving characteristics of the two.

No offence intended. Its just that sometimes this forum goes through "silly season" with inexperienced car owners, kids, etc. so I had no idea of your mechanical know-how.