5spd automatic transmission problems.

Post by **newMercowner69** » Mon 17 Aug, 2015 1:17 pm

Yesterday afternoon i started expereincing transmission problems,
At 60kmh the rev counter/tachometer instead of sitting on between 2000-2500 rpm it started over-reving,
& NOT changing/shifting gear when it finally DID shift it was with a "jerk/jolt" both at low speed(60kmh) even at 2-kmh.The car's just done over a genuine 144k &transmission fluid's been changed as fluid is clean&clear,
Anyone else expereince/have these problems?,'
Would the data plug be the cause/source of the problem?.

Post by **ansteadeh** » Mon 17 Aug, 2015 10:29 pm

Check that you don't have coolant in the trains fluid. What is the brand of the radiator?

Post by **newMercowner69** » Tue 18 Aug, 2015 12:14 pm

HOW would coolant get into the transmission fluid?,
The radiators genuine o.e.m. Mercedes Benz.

Post by **ansteadeh** » Tue 18 Aug, 2015 12:31 pm

If the fluid is Ok and presumably at level then you may not have the dreaded Valeo Radiator problem. At about your era of motorcar Valeo was supplying these to the factory and in some circumstances the transmission cooler (integral to the radiator) cracked or corroded allowing trans fluid and coolant to mix

Post by **tsharkey** » Tue 18 Aug, 2015 7:12 pm

newMercowner69 wrote:Yesterday afternoon i started expereincing transmission problems,
At 60kmh the rev counter/tachometer instead of sitting on between 2000-2500 rpm it started over-reving,
& NOT changing/shifting gear when it finally DID shift it was with a "jerk/jolt" both at low speed(60kmh) even at 2-kmh.The car's just done over a genuine 144k &transmission fluid's been changed as fluid is clean&clear,
Anyone else expereince/have these problems?,'
Would the data plug be the cause/source of the problem?.

Which model is you car ?
What do the diagnostic codes for the transmission say ?

The later 722.6xx transmissions (i think from 1997 to 2004 in most models) have all sorts of wear & tear issues at this age - All fixable.

Post by **Ivanerrol** » Tue 18 Aug, 2015 10:15 pm

It's essential to get the codes read and diagnosed correctly.
A faulty air filter meter can cause problems that seem to be transmission related.

Post by **newMercowner69** » Mon 24 Aug, 2015 10:58 am

Ta fellas for all of the advice as i'm NOT a MERC mechanic i both DON'T know&NOT sure WHAT the codes say,
I've had the data plug &lock pin fitted& it's fixed the problem (so far) it's been nearly a week since i've had the repair work carried out so i assume&think that if it wasn't fixed/solved the problem would still re-appear?.

Post by **frendomech1** » Wed 02 Sep, 2015 9:09 pm

low transmission oil level will cause shifting problems, The electrical plug in the transmission is very common to leak and leak alot of oil in these transmissions see how, if it is still going good i assume its ok, other common problems for shifting is radiators failing annd leaking coolant into the transmission oil cooler and speed sensors in the transmission electrics plate faulting

Post by **Moopere** » Thu 15 Oct, 2015 2:34 pm

newMercowner69 wrote:Ta fellas for all of the advice as i'm NOT a MERC mechanic i both DON'T know&NOT sure WHAT the codes say,
I've had the data plug &lock pin fitted& it's fixed the problem (so far) it's been nearly a week since i've had the repair work carried out so i assume&think that if it wasn't fixed/solved the problem would still re-appear?.

Ahh, I just posted about a really similar problem on my 2008 CLC - didn't see your post before I did.

viewtopic.php?f=26&t=21693

This sounds a bit like my issue - its sounds like its getting stuck in a particular gear. I was running down the freeway at 100KM/h in 2nd the other day, it just wouldn't shift and I had to pull over, turn off the car, then on again and all was (apparently?) fine.

What is the "data plug & lock pin" that you speak of? I'm going to go up and see MB Star (an indie) in Osborne Park next week about this issue, and your commented part sounds a lot like the little inserted pin/plug thing that some merc owners fit to bits of the harness to stop oil travelling up the wiring. If so I'm interested as this is usually a cheap but effective fix for oil/harness related problems (and I've had two f these fitted inside the engine bay). At worst can't do any harm as all my other options seem to start at about $500 bucks and go skywards from there :)

Post by **Ivanerrol** » Thu 15 Oct, 2015 6:35 pm

Moopere wrote:
Ahh, I just posted about a really similar problem on my 2008 CLC - didn't see your post before I did.

viewtopic.php?f=26&t=21693

This sounds a bit like my issue - its sounds like its getting stuck in a particular gear. I was running down the freeway at 100KM/h in 2nd the other day, it just wouldn't shift and I had to pull over, turn off the car, then on again and all was (apparently?) fine.

What is the "data plug & lock pin" that you speak of? I'm going to go up and see MB Star (an indie) in Osborne Park next week about this issue, and your commented part sounds a lot like the little inserted pin/plug thing that some merc owners fit to bits of the harness to stop oil travelling up the wiring. If so I'm interested as this is usually a cheap but effective fix for oil/harness related problems (and I've had two f these fitted inside the engine bay). At worst can't do any harm as all my other options seem to start at about $500 bucks and go skywards from there :)

2008 CLC four cylinders were a W203 platform with W204 styling components. Four cylinders carried on with the 5 speed 722.6.
The Valeo radiator issue was fixed up well before 2008.

Sounds like your car has gone into limp home mode - stuck in second gear. You will need the codes read as there are a multiple amount of issues that cause limp home mode - even a faulty AFM can cause this.

Post by **Moopere** » Fri 16 Oct, 2015 12:35 am

Ivanerrol wrote: 2008 CLC four cylinders were a W203 platform with W204 styling components. Four cylinders carried on with the 5 speed 722.6.
The Valeo radiator issue was fixed up well before 2008.

I sorta hoped but wasn't sure about this - thanks for the heads-up.

Ivanerrol wrote: Sounds like your car has gone into limp home mode - stuck in second gear. You will need the codes read as there are a multiple amount of issues that cause limp home mode - even a faulty AFM can cause this.

Yes ... limp home mode, thats what I thought too. Wandered off to the dealer shortly afterwards and they couldn't get anything useful from the codes. went back a second time a month or so later with the same result - nothing interesting coming in code wise. If the car isn't faulting when its driven into the mechanic it seems to be a bit hard to really make a judgement on whats going on apparently.

In any event, I'll get a second opinion from an indie I think. The speedtronic failing thing is becoming more and more frequent so perhaps there will be something useful in the computer log relating to that which might trigger a thought as to what, if anything, is related gearbox wise.

Post by **newMercowner69** » Fri 16 Oct, 2015 3:11 pm

Turns out all that's causing the problem was low transmission fluid which the mechanic at M1 MOTORS Nunawading when replacing the data plug SHOULD'VE been aware of &know seeing as there Mercedes Benz "experts"!,
Nearly could've cost me $2k for a NEW transmission!

Post by **Ivanerrol** » Fri 16 Oct, 2015 6:44 pm

You won't get a new 722.6 for $ 2K try six to seven times that.

There are no dipsticks on the post 2001 transmissions. There is a special
Procedure required to change a 722.6 fluid and filter. This involves temperature
Measuring wands and special measuring rods.

There are no oil dipsticks either

Post by **Jez280CE** » Wed 30 Mar, 2016 9:38 pm

Hi there.

I have a 2003 C200 Kompressor (CL203) with 165k on the clock and the 722.6 is starting to show lumpy/jerky shift signs. Before I start draining fluids, pulling pans, conductor plates and connectors out I want to check if there is any ATF in the transmission ECU. Only trouble is I'm not sure where it is!

Is it accessed via the front foot well from inside the car - behind the carpet and via an access plate? Driver or passenger side?

I checked in the fuse box, drivers side, back of the engine bay, but it doesn't appear to be located there. Any assistance much appreciated.

(Side note: I joined this forum many years ago when I had a 280CE, bought from John Green. Great car, I was a fool to sell it. Got my C200 only recently, really enjoying it, and I'm glad to be back in a merc and learning as much as I can from the forum!)

Post by **Jez280CE** » Thu 31 Mar, 2016 6:49 pm

Answered my own question - passenger side. Pull carpet back from right under footwell, remove polystyrene cover, undo 3 bolts (one up, two near floor) and pull the metal plate towards you.

ECU (or EGS as it is also known) is held by 2 x T20 screws, easy to remove.

While there was some evidence of ATF 'whicking' up the wires to the ECU none had actually made it which is great news. Removing the two plugs into the ECU revealed it to be dry as inside, no need to clean it out.

So, all roads (hopefully) point to just a change of filter, new ATF and new plug adapter. Should be pretty cheap and easy. If the problem persists I'll change the conductor plate. Better buy a dipstick...

Post by **Moopere** » Sat 24 Sep, 2016 11:06 am

Jez280CE wrote:So, all roads (hopefully) point to just a change of filter, new ATF and new plug adapter. Should be pretty cheap and easy. If the problem persists I'll change the conductor plate. Better buy a dipstick...

How did you get on?

I'm still struggling with my 2008 CLC and lumpy changes as well as occasionally getting stuck in 2nd gear ... though this has happened less than usual over the last 6 months or so (cold weather??).

Post by **AMG** » Sat 24 Sep, 2016 1:38 pm

solenoid packs, conductor plates, plug connectors etc.. all common problems and quite well documented. Most important thing is to physically inspect the basic and obvious contributors first - fluid, filter connector plug & wiring etc, make sure to read the codes and reset, before throwing money hand over fist at them. Conductor plates are becoming more prevalent as are solenoids, but it's expected, given the age and mileage of these vehicles. heat cycling in traffic does them no favours either.

Post by **Jez280CE** » Thu 29 Sep, 2016 7:15 pm

Moopere wrote:
Jez280CE wrote:So, all roads (hopefully) point to just a change of filter, new ATF and new plug adapter. Should be pretty cheap and easy. If the problem persists I'll change the conductor plate. Better buy a dipstick...
How did you get on?

I'm still struggling with my 2008 CLC and lumpy changes as well as occasionally getting stuck in 2nd gear ... though this has happened less than usual over the last 6 months or so (cold weather??).

You know Moopere, I've done absolutely nothing about it as I got a new company car not long after posting. A whopping great Isuzu D-Max which is quite a different driving experience to the quirky-merc... Hardly any km's driven in the C200 since so I have put it off.

AMG is right though - there is lots of info on problems and (relatively simple) fixes for the 722.6, especially on youtube. Search '722.6' and 'Kent Bergsma' and you'll find a detailed series on the subject (sorry moderator if I'm overstepping the bounds by posting that).

Still on my to-do list! I did get a quote for new connector plug, conductor plate, fluid change etc from a merc guy on Gold Coast for about a grand. Doing all of that yourself would be around half that. Still no guarantee it'll fix the problem however...

Post by **Moopere** » Thu 20 Oct, 2016 5:44 pm

Jez280CE wrote:AMG is right though - there is lots of info on problems and (relatively simple) fixes for the 722.6, especially on youtube. Search '722.6' and 'Kent Bergsma' and you'll find a detailed series on the subject

Thanks for the heads-up. Very interesting to watch.

Post by **Moopere** » Fri 21 Oct, 2016 1:19 pm

Jez280CE wrote:]I did get a quote for new connector plug, conductor plate, fluid change etc from a merc guy on Gold Coast for about a grand. Doing all of that yourself would be around half that. Still no guarantee it'll fix the problem however...

After watching all that guys videos on youtube I am very tempted to go with his broad recommendations ... as a matter of course just change the conductor plate, the connector plug and the fluid/filter (as I've done well over 90K on the current fluid, though I did get it changed at 60K per factory spec).

Thanks for giving an indication of price ... about a grand. Plus or minus a bit I'm sure and over here in WA more likely to be + hehe. Still, as my post history indicates, this problem isn't just going to go away on its own and the car is otherwise in fine condition and drives pretty much like it did when new.

Interesting to me was that I found out, from the video's, that there is some type of speed sensor attached to the conductor plate, its different from the main car speed sensor I think .. if I interpreted what I saw correctly. At the same time as I started having trans trouble I also had cruise control trouble pop up ... something speedtronic related - or so the dashboard warning suggested.

One wonders if I'll cure a multitude of ills at once by going down this road.

As everyone says though - no guarantee. Still, I have to do something.

Post by **chopper0813** » Sun 16 Jul, 2017 5:05 pm

About three months after I purchased my W202 C200 (722.6), I elected to have the transmission oil changed, subscribing to the current trends in "sealed for life" transmissions, which seems meant to "seal out" the vehicle owner. (145,000km)
I purchased a transmission oil change kit consisting of a gasket, filter and adapter plug and had the transmission oil changed as part of my regular engine oil change service.
I have been extremely satisfied with my independent mechanical workshop, but the oil change eventually lead to a string of problems.
After the service, I checked the transmission oil level at 80Deg. C., the oil level exceeded dipstick maximum by about 750ml and was a muddy brown colour. The excess oil was syringed out.
I can make the assumption now, that apparent unfamiliarity with 722.6 transmissions, lead to the torque converter not being drained and the transmission not being flushed before refilling. Wrongly, I did not have the oil changed again in an auto transmission shop.

Two months ago, the changes between 2-3 became lumpy, closely followed by changes between 3-4. After several days of lumpy changes it entered No 1 limp mode (Mechanical-hydraulic emergency running mode) which can be reset by turning the ignition switch off. A few days of this, then electric emergency running mode appeared, leading to selecting drive with a significant thump (second gear only and reverse available). Not resetable.
My newly found auto transmission shop read the codes and advised the purchase of: Sonnax Master Overlap Control Valve Sleeve Kit 68942 05K, a Sonnax Regulating Pressure Control Valve Spring 68942 01 and a conductor plate, gasket, filter and connector kit. I also supplied their recommended oil, Penrite ATFS, in sufficient quantity for a significant flush. Six hours after delivering the vehicle to the workshop, it was returned in excellent shape, a little rough for the first 20km, but now extremely smooth.
My knowledge of 722.6 transmissions and their lubrication is now much better that it was.