STEVE: In ref. to a post reply. - PeachParts Mercedes-Benz Forum

420benz · #1 09-02-2003, 08:30 PM

Steve, the question was about harsh trans. shifting from 3rd into 4th.Your reply was to adjust the T bar in the modulator.My problem was solved by making the same adjustment,but it did not solve the harsh thump from N to drive.The trans. shifts at the correct speeds but i can not solve this problem.Is there another adjustment [internally or externallu] for this problem?BTW the flex disks are in good condition and the RPM's are at 6000.

kerry · #2 09-02-2003, 08:51 PM

There'd probably be a little less thump if you had those rpm's down to 2000-3000!

420benz · #3 09-02-2003, 09:10 PM

KERRY: Read many posts stating that the RPM'S for this car should be around 5to6000.If this is not correct how can i lower it?

tvpierce · #4 09-02-2003, 09:34 PM

Are you saying your transmission won't shift from 3rd to 4th until you reach 6000 rpm? I don't know your car specifically, but my guess would be that if you accelerate slowly to 40 mph, then ease off the gas, your transmission should be in 4th gear. If not, it needs adjustment.

Jeff Pierce

Gilly · #5 09-02-2003, 09:50 PM

I think maybe you're trying to say that the engine is idling at 500 to 600 rpm when in gear?

Gilly

420benz · #6 09-02-2003, 09:53 PM

NO: What i am saying is that shifting through the gears is o.k The problem is from N TO D. THAT is when it thumps.

Gilly · #7 09-02-2003, 10:18 PM

OK, just need to clarify what you mean when you said this:

Quote:

BTW the flex disks are in good condition and the RPM's are at 6000.

WHEN are the rpm's at 6000?

What I thought you meant is that the rpm's are at 600 (not 6000) when the thumping occurs. Alot more than thumping is going to occur if you shift from N to D at 6000 rpm!

Gilly

420benz · #8 09-02-2003, 11:20 PM

Sorry, needle is just above the 5 at idel.I think this is the correct idel speed.

Gilly · #9 09-03-2003, 12:00 AM

Quote:

I think maybe you're trying to say that the engine is idling at 500 to 600 rpm when in gear?

(I just love doing that, sorry!)

Gilly

420benz · #10 09-03-2003, 08:14 AM

Gilly: If you don't understand the question,then please let somone else try to answer it. [At normal idel,the thump takes place when shifting from N TO D.]

Gilly · #11 09-03-2003, 08:41 AM

Ya, excuuuuse me for trying to make sense out of your post, YOU'RE the one who listed your rpm's at 5000-6000, not ME. Then just a big run-around when I tried to correct you in a nice way.

If the flex disc and coupler are in good shape, you can also look for other signs of drivetrain lash, such as the center joint and mid-ship bearing, and excess lash in the differential, this all has to be checked with the car in the air (ie on a hoist or the rear wheels jacked up off the ground).

Gilly

ps we have the weird timing thing going on again, this should be behind SteveB's last post. The time on this post is correct, I posted it at 741am. Steve, I assume your time zone is set correctly (Eastern time)?

420benz · #12 09-03-2003, 09:05 AM

SORRY GUYS BUT I THIUGHT I CORRECTED MY MISSTAKE 6 THREADS ABOVE. At 5 to 600 rpms this thump is very harsh.With the car in N on a flat surface i can turn the rear drive shaft approx.1/4" and the front drive shaft approx.3/4" I do not know where this thump is comming from. I SEE THIS REPLY IS IN THE WRONG PLACE.

tvpierce · #13 09-03-2003, 09:25 AM

When my Transmission Control Pressure Cable was out of adjustment, it caused -- among other things -- a "thunk" when shifting into "Drive", and harsh shifts from 3rd to 4th. Are you sure yours is adjusted properly?

A board member e-mailed me a file from the repair CD outlining the procedure for adjusting the cable (on a 201). I would be happy to foreward it along to you. Just let me know.

Jeff Pierce

420benz · #14 09-03-2003, 09:33 AM

I would like to receive this info.p_kohberger@yahoo.com But i thought that cable [BODEN] was only to adjust the speed that the trans. shifts from 3rd. into 4th.

Gilly · #15 09-03-2003, 09:35 AM

If the front half of the driveshaft has a different amount of lash than the rear half, then obviously there is some problem in the center joint of the driveshaft. Can you get a helper to hold the front or rear half still (don't let it rotate) while you try to twist the other half? The driveshaft should rotate as 1 unit, not half rotating a certain amount and the other half doing it's own thing.

Gilly