Jerk in transmission, -problem solved!
 

I had a couple of years ago an amateur change my transmission oil.
Big mistake...

After that, I experienced a sudden jerk (like you´re hit from behind) at low
speed when engine and transmission were cold. After warm-up it dissappeared.

Couldn´t live with that so I let a transmissionspecialist look into it.

He took the gearbox off and changed following parts:

-converter
-both "freewheels"
-1:st, 3:rd and 4:th gears (3:rd gear looked burnt, the edges on the others
wasn´t edgesharp)
-conductorplate
-oil & filter
-all gaskets
-a greasevalve.

Got it back but the jerk was still there, but less violent.

Then he suggested to change the solenoid in the gearbox as well.

After that the gearbox performs brilliant without any jerks!!!
It goes like a dream now, really.

I suspect that loose dirt hit the solenoid at the first oilchange.

Voila, problem solved!

(It didn´t come cheap though...)

Whats "not cheap"?

Congrats on solving the problem. Which solenoid was it? The one for the torque convertor? part #?

what was the name of the amateur shop that busted your transmission?
didn't you complaint to them?
they had to fix your transmission under shop insurance.

:naughty:Title should have read... Jerk changed my Trans oil.

The "amateur" is a Mecedes enthusiast who owns 20-30 older Mercedes.

He´s doing Mecedes jobs after work with no warranty.

Maybe he can change engineoil and easy jobs but he should stay away
from modern cars like ours. He hasn´t even STAR.

I suspect he used the wrong transmission oil or didn´t fill it up the first time
with damage as a result. And he only cleaned the filter instead of change it.
Maybe debree came loose and got stuck where it shouldn´t, at the solenoid?

His garage is a mess, I say never again!!


The transmissionspecialist called the solenoid for "PWN solenoid", and I got
the impression that it´s located in the valveunit in the transmission.
When I asked him what it does he answered "it controls about everything,
including the lock up of the torqueconverter".

Anyway, I´m very happy the problem now is solved! :)

I think you had a jerk causes from "2" control modulating & pressure solenoids,

and the wrong signals from the RPM sensor that located in the conductor plate only,,

not have to be complete rebuild....:rolleyes:

Glad you solve it MaaaaN...:y,,

ZAYED,,

How easy was it to replace the solenoid? Was the transmission back out of the car again?

No, but the pan was down.

Thanks for this, I think this is the answer I've been looking for - I have the same issue, when cold I get the big jerk but after warm-up no problem. I searched my service CD for PWN, got PWM instead but PWM is the solenoid that controls pressure for torque converter lockup. Stands to reason that if it's worn or dirty that when cold it might be sticky. I'm going to have my very reliable indy mechanic change mine out. I found a part #240 270 16 00 on RMEuropean (for only $57), but I'm having trouble verifying that it's the right solenoid, do you know what the P/N was on the one you replaced?

I've noticed more torque converter jerk recently while the car is cold. I'll subscribe to this thread in anticipation of more confirmed solutions! :y

I think you´re spot on!

By the way, the transmissionspecialist called it "PWM solenoid"
and nothing else!! Sorry, will help and not misslead anyone! Fat fingers.. :smash:

So is this the only culprit? About how many hours labor to change the PWM solenoid out? Thanks!

It shouldn´t take long: pan down and maybe the valvehouse out to change it.
1 hour maybe for a good mechanic. :)

That's great news! Thanks a lot man!

Pretty sure I've found the part, it's 140 277 04 35, with shipping from mbpartsworld $67.95.

Item #35 in this pic:


Attachment 279597

Feels good to help!

Know many with this problem and no one had come up with a solution.

I found it but it cost me half a leg, but on the other side I have almost
a new gearbox now!

Looks like the right one! :)

Amazing how a random run thru the forum can potentially solve a long-standing problem; I've had the 'jerk' since I bought the car with 70K miles on it (up to 155K now), and it was bad enough when I first got it that I took it to a different (crooked) indy Mercedes mechanic who told me I needed a trans rebuild to the tune of $3700. The jerk sort of went away but not entirely, and crept back in over time. I've read a ton about it on this forum but most of it pertained to the bad radiators in the '02-03's, nothing has really clicked for my '04 like this solution. I'm sure amgen that if I'd known what you just turned me on to that I would've saved over $3K :hammer:

Thanks again.

Yes, this is the solenoid that controls the tq. converter lock-up,

side note; if you want a good upgrade for shift delay or jerking, time to replace the "2" Brown top solenoids to the Blue top solenoids, then reset the TCU, you will definitely surprise.....;)

ZAYED,,

Funny that this transmissionspecialist changed all these parts in my transmission. Ok, 3:rd gear looked terrible but I hadn´t had any problems with it at all. He told me that within a year I could have a problem. But he didn´t change this solenoid... -Smart mister?
But on the other hand he revealed "the bad guy" when he took the car in for the second time, "we should change the solenoid too"! Free of charge after 3,8 k dollares.
He had several digital testriggs at his disposal, but when he fitted the new solenoid he said "we have different readings". Since the tests were done with
78 C degrees heated oil, the problem probably didn´t occur the first time and everything seemed fine.

I´m just happy to be able to pinpoint the real problem in this speculative issue.

If he had changed the lot the first time, I couldn´t share this with you guys.


My joy is the sharing. But of course my smooth gearbox too! :)
The TCU-tune makes the car sportier too, trust me! :music:

I have that jerk but when the tranny it Hot, if i reemplace this solenoide i can fix that, and run more smooth?

to clear misunderstandings out.
isn´t the solenoids for gears different from the PWM solenoid AMGEN replaced?
I might have misunderstood but was it the solenoid for the Lockup you replaced?
If so, lockup solenoid differs from the others i guess?

Well, transmissions isn´t my area so I had to call the specialist.

There are several solenoids in the gearbox (8?).

The one we´re discussing here is the Pulse Wide Modulator Solenoid.
It controls the lock-up of the torqueconvertor.
It´s situated in the valvebody that has to come off in order to change it.
The lock-up slips 1-2% when locked-up, which is completely normal.

The diagnosis in many threads is problem with harsh lock-up when the oil
is cold. So it´s makes sense that it´s the solenoid that controls this process
is the problem.
It isn´t expensive but a bit hard to replace obviously.

If you don´t have any problems, I think it´s a waste of time changing it in prevention.

Mine is working fine,, but i have a small small gearbox issue when cold.
just when start rolling there´s a tiny 'hookup' in lets say 5mph
Like the lookup activates in this low speed.
I almost figures this should be this way due to save fuel.
Otherwise all is good.
Been reading about blue top solenoids several hours yesterday.
I´m starting to belive i got them already.
As people are describing the function: real hard gearshiftes when flooring it - got those!
hard downshifts when throttle is released and gearbox is shifting downwards - got those!
It´s like dumping the clutch on an manual car with 'too low' gear.
And mine was faster to 60mph than it should already as std.
Last, the one that i bought the car from, his dad was working as 'boss' at a mercedes center in Germany.
As the car is retrofitted with some other small things they might have done this too ;)

Is it possible to see color if just taking down the pan to change the filter?

Rgds.


Edit, once i timed the gearshifting in my car as i thought they were quite fast actually.
About 0.7s from when flapping the button on steering wheel.
I read someone else done the same, and it took about 1.05-1.1s