What are symptoms of bad tranny "clutch packs"?
Anyways, the problem is that under light load, without changing gear, i get non harmonic vibration from the drivetrain. It sounds more like from the rear to driveshaft to tranny, but sometimes vice versa. Tranny shift through all the gears fine (at right points).
Negative glycol test and i get no codes. Changed valve body and Tranny control module. 125Kmiles. 03 e500
Last edited by MercFiveHundred; Sep 25, 2009 at 09:10 PM.
If you really think it is the trans (which apparently you do as you've only worked on that) then change the trans mount next before going on to the other.
Mercedes transmission mounts are pretty easy to diagnose. There seems to be a sweet spot around 3000 rpm's where the transmission mount jumps around and lets you know it's bad. With the car in park, rev the engine up to 3000 rpm's and hold it there. If there is a lot of noise and or vibration from the middle of the transmission tunnel area, your trans mount has likely given up.
The reason for another glycol test would be to definitely rule it out. I have run around and around in circles chasing a vibration/droning from what sounded like the rear axle/differential area that turned out to be a glycol contamination issue. I have also seen tests that passed the first time but later on failed as the contamination progressed. Was the test performed by a dealership? If not I would recommend seeing a dealership because it is a pretty sensitive test.
Hope this was helpful.
I had vibration in mine and had the engine and transmission mounts replaced under warranty. Smooth as a new car now. 88,000 miles.
The glycol test was done at the dealership. They are the ones who told me to change the valve body. Another dealership said since glycol was negative and since we changed the valve body, then it's the clutch packs (first time). A different indy (merc mechanic) said STAR shows the adaptations are within range and try the TCM. Spent over $2k (parts & oil only - all labor done myself) and no fix.
Thanks VERY much guys. Cant get more frustrating than something being broken and no one knowing what's wrong. AND it's NOT getting worse! LOL
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I did the tranny mount test and it did vibrate a little bit - but not at 3000 RPM. It DID however slightly vibrate as it would have vibrated if i was driving it (from 1500-2700 RPM). I will buy a tranny mount and put it on over the weekend and see if it fixes it. As for glycol, although it was done by the dealership, i'll get a second sample and get it blackstone labs to check again. I do have the Valeo radiator (and 3 weeks ago got a one time "check coolant level" that never came back). It's a May 2002 production date
. Dealerships were pretty convinced that it was NOT glycol because of the high mileage - should have went a long time ago. And do you think if i did have glycol that i would be able to drive it for 15K miles longer? And if it is contaminated, would a dealership help me with getting the tranny replaced - since this is a well known design flaw?Thanks again.
Last edited by MercFiveHundred; Sep 27, 2009 at 01:27 PM.
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If he did this while the car was stopped. He's not checking the "lock up" function of the torque converter. The converter doesn't "lock up" while the car isn't moving. When it "locks up" it's basically direct drive(like letting out the clutch on a manual transmission). I don't think it locks up until 3rd gear. You have to drive the car with a scanner and watch the solenoid command. If the converter wasn't locking up at all, I'm sure it would trigger a cel, due to the engine rpm vs. vehicle speed.
You did say it's a vibration, this is just something to consider if it you can't isolate the problem.
As far as the dealership helping you with the repair due to glycol contaminaion, if it's a decent dealership they should be willing to give you some sort of discount. Not due to the fact that it's a common issue, but more so because you went to them and spent some money for diagnosis.
Good luck and let us know what happens with the trans mount.
So i took some tranny oil out from the pan and ill send it over to blackstone labs.
the end is near...
I also realized something. When i drive "slower" - like in no traffic, just cruising straight at speed limit, it doesn't do it as bad - even when i push it up a hill a bit. I've also noticed that when i disconnect the battery, the same happens, until i drive the work the next morning in traffic. Could this be an issue with cooling?
Thanks for all the help guys.





