Newbie w/Trans. Problem - PeachParts Mercedes-Benz Forum

corohio1977 · #1 05-04-2009, 06:14 PM

Hello all...I'm Corey & new to the forum.

I have an 89 560SEL with 126.2k on the clock. Yesterday, as I was driving back to East Lansing from Cincinnati, I developed a transmission problem: The car starts out 1st gear will hold onto 2nd gear, occasionally go to 3rd but RARELY 4th. I tried manually shifting from a stop but when doing so, it would sometimes shift to 4th but kick down to 3rd. I tried to 'gun' the motor to force a downshift then upshift but that did nothing (but it was fun to see just how powerful it still is after 20 yrs.) and to make matters worse; it got to the point where it would only shift into 2nd gear. I pulled over to let it sit on the highway for a bit then attempted to 'limp' home. Oddly, it shifted to 3rd on its own but once off the highway, back to 2nd only.

I recently had the transmission serviced @ local independent specialist here in Lansing who comes highly recommended. He went over the car and advised that in addition to the aforementioned transmission service, the only other item needed is an "idle speed control" which he says regulates the idle (current resting idle is around 1200 rpm instead of 600-750).

I checked the AT fluid this morning, it shows currently on the 1st mark (I'm told it should be @ the 2nd) which he thinks there may be a line/hose that may have deteriorated over the 70mph plus drive to Cincy - to his credit, this is the first time that the car has done any MAJOR travel in 20yrs, it truly was a grocery/church, <150mi trip car.

If anyone has any clues, helpful hints, etc., it's GREATLY appreciated. Until then, it's back to driving the MINI.

Thanks!!

mbdoc · #2 05-06-2009, 08:45 AM

Sounds like a clutch pack issue. 560's should start in 2nd gear.

Do top off the trans 1st.

Vacuum lines that leak will NOT cause that type of problem.

corohio1977 · #3 05-06-2009, 11:41 AM

I recently found out they start in second - so I stand corrected on my initial post.

However, I did attempt to drive it for the first time since this happened and it's still doing the same thing. It'll run in 2nd up to about 4500-5k rpm (40-45mph) and it only shifted into 3rd ONCE.

Did another check of the trans. fluid - before and after the drive. Before it was showing right above the 1st notch (car sat running for about 10min) then After, it was showing right above 2nd notch.

I was advised on another forum (benzworld.org) to check vacuum lines - but have NO idea of where to even start w/that.

mbdoc · #4 05-06-2009, 12:20 PM

Try disconnecting the kick-down solenoid on the rear of the trans, passenger side & see if the problem goes away.

corohio1977 · #5 05-06-2009, 02:47 PM

What exactly am I looking for under the car? Not to sound like a complete moron - but I'm not mechanically inclined.....

mbdoc · #6 05-06-2009, 03:30 PM

Just the only single wire electrical plug on the rear of the transmission, Passeneger side.

corohio1977 · #7 05-06-2009, 04:40 PM

Also, where is the Bowden cable? I've been reading through some of the other posts that sound similiar to what I'm experiencing.......

I can't begin to thank you for the help!!!

tinypanzer · #8 05-06-2009, 05:10 PM

Perhaps it's the kickdown switch under the gas pedal?

corohio1977 · #9 05-06-2009, 08:12 PM

Kickdown switch? Is that something I can disconnect? I'm still trying to find the damn Bowden..... LOL.