manual transmission jerking mystery

[trade1952]

I have a problem in my 1995 w202 C180 Manual Transmission model. The problem is when I engage the 1st or reverse gear, mostly on reverce gear, and trying to start smoothly,( letting go of the clutch slowly, and obviously giving the car enough gas so it's not stalling or anything), like as unpark carefully with slight accelerator (I'm about 50% off the clutch), the car starts jerking with clanks and only if I release completely the pedal quikly everything going normal.
All the other gears shift fine, No jerk even I start with 2nd gear.
Clutch kit, flyweel and trasmission fluid has been replaced three months ago. Also we have found out that the previous one ( the old one) was in a good condition and the idiot problem remain exact the same.
Gearbox rear mount and propeller shaft couplings are ok.
No any fluid leak inside or outside transmission and the funny mystery is that if i don't drive the car for a day the problem dissapear and everything is smooth and perfect, but then after I drive for a bit (~30 min), especially in traffic it will be present again. The problem went bad to worst during the driving day by day.
Any comments of this problem?
Thanks in advanced
Mike

 

[ernieh]

Transmission Judder

First of all, a very warm welcome to the Forum; hope you find it as useful as many of us have!

As to your problem, you mention that the gearbox rear mounting has been checked. As the problem is worse in first and reverse, I would also be looking carefully at the engine mountings. I might be wrong, but if these are oil-filled as I think they are, this might account for the change after 30mins driving. In particular, look for separation of the bonding between rubber and metal, cracking of the rubber and also oil leaks around the mountings.

Somebody else with more specific knoweledge might be along shortly to add to the above.

Hope this helps,


Ernie

 

[trade1952]

Ernie, Thank you for your welcome messsage and your reply.
Engine and gearbox mountings has replaced a year ago. I 'll check them again ..
Anyway the clanks comes from gearbox and I feel like a continue instant clutch slip and jam while whole car start jerking. This happen only with half clutch pedal with 1st and reverce at slight acceleration, but not always.
It's drives me crazy.

Mike

 

[ernieh]

Transmission noises

Hi Mike,

Since you seem to have covered most of the obvious possibilities, a couple of other things to check when you are in there.....

1. The centre propshaft bearing - I think there is one on that model - check the bearing for free play and also examine the rubber/metal bonding, if necessary, using a screwdriver gently to see if there is any separation of the two.

2. Check that the gearbox casing isn't cracked in the region of the mounting. I haven't seen that as a fault that comes up in these forums, but it might not be obvious if examined when the car is at rest. I would try to check this using a trolley jack to just take the weight of the gearbox off the mounting, and using a piece of wood to spread the load of the jack on the gearbox casing. Check also that the mounting is secure and that the screws are tight.

3. I know you said that the clutch was replaced, but the symptoms are also similar to clutch judder due to oil contamination of the friction plate. Check that there are no oil drips around the bell-housing.

It would be helpful if someone with specific knoweledge of this model could comment further.

Best regards,


Ernie

 

[trade1952]

Problem seems solved

We found out that the clutch disc engaged the half of the pressure plate surface. It happen because the center teeth of clutch disc was defective and it jammed momentary at the input (clutch) shaft.
Complete clutch kit replaced again and now everything is normal.
Thanks again Ernie for your replies
Mike

 

[television]

Good news Mike and pleased thats it all fine now, info on the manuals is hard to come by but we will remember this one.

Thanks for feedback

 

[ernieh]

Clutch Fault

Glad everything is now OK. To be honest, that is one fault I wouldn't have thought of. It might be usefult to know if the first replacement clutch was from MB or was it from an independent supplier. If so, was it one that we recognise?

Regards,


Ernie

 

[trade1952]

The first replacement clutch was from an independent supplier. As about the problem, I'm afraid that mechanic didn't tell me all the truth. I believe that they didn't grease the clutch saft at first replacement, but I can't proved it..
Anyway they replaced it with out charge (parts and labor).

Mike