2000 clk 320 722.6 3-4 shift flare - PeachParts Mercedes-Benz Forum

frankyg · #1 09-16-2010, 08:55 PM

Hi,

I have a 2000 CLK 320 with the 722.6. yesterday the transmission shifted fine in all gears except 4th, which it went into neutral. However when it was driven for about 15 minutes it would shift into 4th with a little shift flare.

Today I cleared the codes and did a reset with the pedal, took it out and it shifted every time even when cold but has a 3-4 shift flare.

My 3 tranny codes are :
P136 SPORADIC FAULT IN CONTROLLER AREA METWORK COMM WITH EIS
P146 SPORADIC IMPERMISSIBLE TRANS RATIO
P147 SPORADIC GEAR IMPLAUSIBLE OR SLIPPING

Any ideas?

thanks

mbdoc · #2 09-17-2010, 08:23 AM

Has the fluid level been checked? has the fluid been changed as well as the filter?

ASSuming yes, you have a worn out clutch pack.

Gilly · #3 09-17-2010, 05:10 PM

How many miles on the car?

frankyg · #4 09-17-2010, 09:37 PM

i just bought it. It has 111k on it.

As far as the clutches, It shifts from 5th to 4th great (no delay), just has a 3-4 flare.

Also very fast and positive from park to drive and drive to reverse.

I was wondering about the K3 thing.

I would like to be able to pinpoint it better before I change the fluid and filter, so I can repair the valve body or ? while I am Im in there.

I figured the 3/4 shift solenoid would give a code if it was bad, but maybe not.

I see no leaks from underneath and there is no fluid at the tcm.

I have an OTC genisys with the euro package and ordered a carsoft 7.4. with multiplexor.

thanks for the replies guys.

Gilly · #5 09-18-2010, 04:44 AM

You'll be able to tell a lot once you get the pan off, by the amount of shavings or graphite sludge that are in the pan.

david s poole · #6 09-18-2010, 10:28 AM

you understand that this is a 722.6 and as such is electronic.those early model .6 trannies had some issues and were subsequently updated.when you take the pan down be sure to cut open the filter and check for metal debris.even small parts are significant as there was a bearing that tended to come apart.they are not like the 722.3 trannies that you see a lot of discussion about on this board.

frankyg · #7 09-18-2010, 01:29 PM

kk i will get the pan off and post back

gregs210 · #8 09-18-2010, 04:35 PM

Can't believe no one's mentioned the 800 lb elephant in the room.

There is an electrical conductor plate above the valve body that has an external connection to the TCM through a harness and a spacer/adapter/connector located at the right front of the AT.

The connector is known to leak fluid and sometimes it will travel up the harness and flood the TCM, with lots of unhappy results.

So I'd suggest ordering the connector (very cheap) and plan on replacing that after you've drained the fluid (once you drain the fluid there's less leakage) and if the harness end is wet when you remove it from the connector, then go open the TCM and see if there is fluid in there. If so, remove it and clean it, then flush the harness with some electrical spray (with it disconnected below it will rinse out) and let dry before reassembly. Usually the TCM survives.

Additional notes: use MB spec fluid 236.10 or higher, unless you know what you're doing just get it at the dealer (regular auto parts stores will not have it). Buy 4L, you'll lose a bit over 3 when you drop the pan. You also need a dipstick tool, sold on ebay for about $25 with shipping. An inexpensive infrared thermometer will help you know when the fluid is at 80c for final level set.

Only bad thing is that you can't clear trans codes with a regular code reader. You'll end up paying a shop to clear them ($50-150 depending on the shop and market). You might consider changing the connector yourself (and cleaning the TCM, etc.) and taking it in to have the fluid changed, that may save a bit considering you won't have to buy anything.

Outstanding FAQ with details, pictures, links at Benzworld in the W210 forum DIY stickies.

Good luck.

Gilly · #9 09-18-2010, 09:30 PM

Likelyhood that it's any of that when the complaint is a 3-4 flare is pretty doubtful. Would be nice if that's what it is, but I think he's going to looking at a lot of graphite (or worse) when he drops that pan. In which case all the electrical spray in the world ain't gonna do him a damn bit of good.

frankyg · #10 09-29-2010, 02:09 PM

Finally got to pulling the pan.

First the transmission has been replaced or rebuilt, it is very clean externally.(just bought it at a dealer auction fro my wife, I"m a used car dealer)

The fluid looked a little burned and dark, but there is very little clutch sludge or metal particles. actually looked very good, except for the oil.

The electrical socket has the upgraded version, but a bit of fluid was in the socket.

Took out the valve body, and inspected the 4 3-4 valves.(no broken springs and no wear on the overlap regulating valve.)

pushed up on the input and outputs, no play in the front input but about 1/16" play on the rear output pushing on the drum.

not sure where to go from here.

Gilly · #11 09-29-2010, 04:40 PM

Well, would have been good to do what MB Doc mentioned, did you check the level?
The fluid will get quite dark without affecting shift QUALITY, but the level is critical.
If you aren't seeing any abundance of chips, shaving, metal flecks, or graphite sludge, you could try the fluid and filter.
A little worried about the status of the transmission, because if it wqas replaced or rebuilt, why wouldn't the fluid be clean?
It does get blackish due to the graphite friction plates. But not in a year or two for example. I would even go so far as to say that the blackness is no reason to change the fluid, that's what MB says too, I can find a link to something I posted here years ago regarding fluid.
It is special MB fluid though, don't cut corners, get the right stuff. That could be a problem as well, incorrect fluid.
The fluid checking procedure is a bit tricky too, some DIYers have ways to check it that they are comfortable with. To do it the MB way you need a shop computer, and you definitely will need a dipstick (special tool but not too pricey).
Gilly

Gilly · #12 09-29-2010, 04:51 PM

Did the shift valves have the plastic caps over them (one cap on each side) and is there a magnetic plate in the bottom of the pan?
Gilly

frankyg · #13 09-29-2010, 06:01 PM

I have the dipstick, carsoft and an infared gun.

The shift valves (not solenoids) did not have any plastic caps. The solenoids had plastic covers. I removed all solenoids and checked ohms. all are good. But the 3-4 solenoid is used for more than the 3-4 shift and with no codes I dont suspect it.

level was a little over a 1 pint high originally, and did puck oil when it got hot and driven an hour or so. stopped puking oil after correcting oil level. However it flared in the 3-4 shift with the oil level high or correct.

The clutch material may have been cleaned out before I got it, they could have replaced just the filter, then it got dark from mixing with the fluid in the converter. Although there was no clutch material or debris on top of the valve body.

Something is fishy with the wear in the output though.

Since the K3 clutch gets applied in 3-4 shift, I suspect the K3 pack. (and since the K3 stays on in 4th and fifth gear, there would be no flare from 5-4. )

I found another 722.618 tranny with 34k miles (out of a 2004),I think I will put that one in it. It comes with a TCM as well for $900

2004 618 should work in place of a 2000 618 right?

Gilly · #14 09-29-2010, 10:33 PM

One would think so but I would run the cars TCM not the one that comes with the trans.

Gilly

frankyg · #15 09-29-2010, 11:26 PM

thanks for taking the time to help everyone, especially Gilly.

What year did they start using bearings instead of bushings on the input/output shafts?

Im hoping the 2004 has some updates.