vibration on gear change 2->1

[hawkeye]

hi Folks,

I've put this on here before but it's getting more interesting now.

Problem:
Auto C220 CDI (2004 reg).
On moving from 2->1 without braking it sometimes feels as if the clutch is sticking and when this happens there's judder all the way from the engine to exhaust. As far as I'm concerned this is happening more now than it used to (only had the car 10 months). Doesn't happen all the time - can sometimes happen when braking very gently too. Mainly happens when going up a slight hill slowly i.e. in a traffic jam and gears move between 2 and 1 "slowly". If I'm "really lucky" I can literally get it for a good second or more.

When I put it in comfort mode it can also happen from 3->2 but because this is at more speed is less noticeable and quicker to change down.

OK, so after much ado many eyes and many ears. All Transmission fluid has been completely changed (and flushed) plus full computer reset. No change - although seems slightly better with new oil. Oil been changed twice now - over period of six months so can't just be that ! (Oil is a symptom surely not a cause !)

Anyhow - MB now reckon that they've seen this twice before with S class (mine's a C) on one occasion it was only fixed by new gearbox - but they never understood why - even after complete strip down. On the second occasion they recommended a new gear box but punter said he'd live with the problem given the price

So, took it back to gearbox specialist (bloke who changed the fluids). He drove with me and reckoned that it was because the engine management system is using the engine to slow the car down and because the engine is quite small (2148 L) that the engine is almost stalling and thus the judder. he reckons its "as per the spec" and that I have to live with it.

Although I can see his logic - I can't believe that this should happen.

Anyone any thoughts ?!

many thanks for any help,
John.

 

[colechelle]

as i found out last weekend when servicing my 55 plate c200, there was a update on the engine control module, flashed up the ecu and gear change is like new, ok im luckly i have a star machine to hand but might give you somewhere to look, any good indis round your way????

 

[toxic]

Hi give this a go

Auto Box Reset
1. Get in your car, it doesn't matter if you close the door or not.

2. Turn the key to the on (not start) position, the position just before the starter turns over.

3. Press the gas pedal to the floor with the key in the "on" position.

4. Hold the pedal to the floor for five seconds, then turn the key back to the "off" position (don't remove the key), then release the gas pedal.

5. Wait 2 mins for a full alignment.

6. Drive the car as you always do.


nothing to say its a dead cert but what the hell it may work .

 

[piestore]

220 gerabox

HI

Toxic info very dodgy sounds like method to program throttle body on old 202 c class, As to your fault. There is a widley known fault with the gearbox oil coolers on these vehicles, they leak coolant into the gearbox oil. the symptoms are normally a vibration felt between 1200 and 1800 rpm while under slight load, very light throttle while going up slight incline usually between 20 - 40 mph try reproducing this

 

[brandwooddixon]

Get the oil tested for glycol contamination. That will determine if you have a coolant leak on the oil cooler.

Note that if you're willing to put up with a nonstandard car, you can just have the oil cooler pipes to the radiator blocked off and an external oil cooler fitted to the garbox pipes. This will save you having to pay for a new radiator.

 

[colechelle]

agree with both post above, but as piestore said toxic info dont work, both olly and me have proved this both using a star machine, that is the only way of changing/updating control units. as for the rad fault like the 209,211 the 203 has never had that fault, ok, i have never seen one since the 203 come out and have never heard of it, i will still advise getting the gearbox updated, updated mine 2 weeks ago at work and its still changing better than ever, same car C200!!!

 

[toxic]

HI

Toxic info very dodgy sounds like method to program throttle body on old 202 c class, As to your fault. There is a widley known fault with the gearbox oil coolers on these vehicles, they leak coolant into the gearbox oil. the symptoms are normally a vibration felt between 1200 and 1800 rpm while under slight load, very light throttle while going up slight incline usually between 20 - 40 mph try reproducing this

Hi did this on my car W210, many others have as well with good feedback, OK it's not up there with the fuel magnet because that cost and don't work, this is free and maybe won't work, don't knock till you've tried it, dodgy sounds a bit harsh i would never knowingly give dodgy information, and some people have said it does/did make a difference, that could be a placebo effect, always go for the cheapest and easiest fault rectification method first, unless you have buckets full of cash to through at these cars, a lot of things can cause vibration on a gear change, transmission mounts, low ATF fluid, Metal filling in the fluid, a warped wheel that can only be felt at low speed, say when changing from first to second, don't always take the word of the STAR machine it missed many a fault code or misinterprated a problem FEEL the FORCE as well when diagnosing faults


regards M>ark