300E Transmission - PeachParts Mercedes-Benz Forum

alsevi · #1 09-21-2006, 05:43 AM

I just bought a sick 1991 300E 2.6 that will not upshift from 2nd. I do not have alot of tranmission information, but enough to check system pressure normal, modulator pressure normal, good modulator diaphram and kick down deenergized. However, there is no govenor pressure. With the shift delay solenoid and tubing removed, and the govenor cover off, there is no fluid from the open govenor test port, nor does the govenor spin with a wheel jacked up and "driving" at 20 mph. The govenor rocks back and forth about 15 degress and seems to be "engaged". This don't sound good. Any ideas? Can the govenor be removed in place? Govenor drive/repair? Need a rebuilt tranny?

mbdoc · #2 09-21-2006, 08:01 AM

Very common problem on the 722.4 series trans.. the governor drive gears are plastic & they are subject to breakage. can be replaced with the trans in the car.

C32AMG · #3 09-21-2006, 10:32 PM

This well help you, But first confirm it’s the governor, with the rear wheels safely off the ground and the governor cover removed start the car and let the wheels turn, look at the governor if it does not turn the driven gear is bad.
http://www.peachparts.com/shopforum/showthread.php?t=144710&highlight=plastic+governor+gear

kjoske · #4 09-21-2006, 10:44 PM

W126 72235 transmission: when put in D transmission shifts perfect 1-2 shift but when it goes to 3rd it spins; when placed in 3 it shifts perfect one shift ten spins next shift; P-R-2 engagements are smooth and w/o problem. Recently installed a new modulator valve no improvement in symptoms but made transmission shift even smoother. Review of threads suggests that it could be adjustable b1 piston; or plastic b2 piston bad; bad governor; front pump. Which is most likely the problem and can it be fixed with transmission in car? I would appreciate any suggestions.
Karl

Johnhef · #5 09-21-2006, 11:52 PM

C32, great link. gave me new hope to save the trans in my friends 88 300E he just bought, I'll take a look at the governor gears tomorrow night- we were just going to stick my spare trans in it-which he can't really afford so I would have been donating it and my services...

this one I could have sworn would shift into third and fourth when we first drove it but wouldnt always shift- when he drove it home (about 50 miles) we almost made it all the way before it started acting up and refused to shift out of second gear. as far as i know, it only goes to second gear now still, no 3 or 4 anymore.

alsevi · #6 09-22-2006, 08:20 AM

Thanks. The question is, how do I unclip the govenor to remove it. I can feel what appears to be a clip end with some spring to it. How and where to grab, tools(?), what not to damage.

romansek · #7 09-22-2006, 10:26 AM

I can lend you my home made pliers which I made for my job.
Good luck.

Johnhef · #8 09-22-2006, 05:38 PM

no such luck yet on mine- govenor spins fine.

i seem to recall the "not shifting out of second" happens after its hot and has been driven awhile...

any ideas anyone? I've got it apart right now on my lift and want to try any suggestions before I put it back together and head home.

Johnhef · #9 09-22-2006, 06:50 PM

well, govenor is out, rear pump is off, and rear cover is off. everything looks fine, I'm just going to yank this ***** out and replace it.

C32AMG · #10 09-22-2006, 10:08 PM

It could be many things, stuck kick down solenoid, disconnect the wire under the gas pedal, KD switch. Hot can be stuck valve in the valve body, or brunt clutches.
If the pan is clean and no debris in the filter, cut it open, change out the valve body as a test.

C32AMG · #11 09-22-2006, 10:14 PM

Quote:

Originally Posted by kjoske

W126 72235 transmission: when put in D transmission shifts perfect 1-2 shift but when it goes to 3rd it spins; when placed in 3 it shifts perfect one shift ten spins next shift; P-R-2 engagements are smooth and w/o problem. Recently installed a new modulator valve no improvement in symptoms but made transmission shift even smoother. Review of threads suggests that it could be adjustable b1 piston; or plastic b2 piston bad; bad governor; front pump. Which is most likely the problem and can it be fixed with transmission in car? I would appreciate any suggestions.
Karl

You E mailed me.
I sent a reply did you receive it.

Johnhef · #12 09-23-2006, 09:52 AM

I disconnected KD the first night we drove it hoping it was just that to no avail. This car needs to get on the road asap, so I'm going back in today to put the spare trans in it. I guess I'll know more after I tear it down. I'll have two extra 300E transmissions now with similar problems.

kjoske · #13 09-25-2006, 10:03 PM

Quote:

Originally Posted by C32AMG

You E mailed me.
I sent a reply did you receive it.

Did not get reply. Can you send the reply again as a PM to my box?
Thank You