'81 240D no fwd, no rev auto transmission! - Page 2 - PeachParts Mercedes-Benz Forum

glowplugged · #16 05-19-2009, 11:41 AM

Is replacing the front pump within reach for a shadetree mechanic? If so, i am not afraid to jump in. Where online can I find info on that job?

Stan

rs899 · #17 05-19-2009, 11:55 AM

If you are skilled enough to get the transmission out and on a bench, you should be able to replace the pump. The only transmission manual I know of for that transmission is by ATSG, but I have heard it is now out of print. I don't know of any online support for that transmission apart from exploded parts diagrams.

Rick

glowplugged · #18 05-19-2009, 01:33 PM

An exploded parts diagram should do. Somehow I can find the torque values and settings requiring micrometers, if necessary. Trying to find a used auto trans up here has so far turned up nothing.

Stan

rs899 · #19 05-19-2009, 03:20 PM

The website at jie.com has a diagram, for starters. There may be some other better ones out there in cyberspace. He may also have some used parts or you can look on ebay. Did you do the seat-of-the-pants working pressure test?

glowplugged · #20 05-19-2009, 03:27 PM

Not until the rain stops! No testing!!!

Cheers

Stan

79Mercy · #21 05-19-2009, 04:20 PM

722.1xx trannys have a b2 piston.

lietuviai · #22 05-19-2009, 04:29 PM

I have an ATSG manual. It is very generic, the steps a bit confusing and the illustrations are terrible.
I found this: http://www.onlinefreeebooks.net/go.php?url=http://www.europeantransmissions.com/Bulletin/DTC.merc/722.1_.2TIPs.pdf
May be of some help?

glowplugged · #23 05-19-2009, 06:16 PM

This is more information than I have. Looks good to me!

Thanks!

Stan

holtonmusicman · #24 05-20-2009, 12:59 AM

First things first before you pull the tranny...

How old are the half shafts? I had a half shaft come apart on me and still looked "together" from the outside.

I also purchase a "cheaper" half shaft that litterally unbolted and came apart. She was driving fine, I got off the hiway, pulled up to a red light, went to give her the gas on green and NOTHING.

Check ALL of the driveline first before you pull your tranny. It's possible she just gave out with no warning, but not likely.

Check to make sure all of the u-joints are in tact and the half shafts are in good shape.

rs899 · #25 05-20-2009, 08:41 AM

Quote:

722.1xx trannys have a b2 piston

Yes, they do indeed, but it is the 722.3xx that exhibits the "classic" piston failure and has had at least 3 redesigns to the piston. That is what the Dieselgiant writeup is all about.

In the "classic" failure mode the 722.3xx tranny will still have reverse but no forward motion.

glowplugged · #26 05-20-2009, 10:25 AM

Recapping the failure and symptoms:

There was no warning. No noises. When I went to leave the parking lot (I had backed into the spot), I put it in drive. There was a small noise, and no motion. I tried all the other positions, no motion. After trailering the car home, same thing, even after the engine was thoroughly warmed up. All linkages, vacuum lines, and the drive line and joints appear to be intact. When I tried yesterday morning to get her moving again, she was at full operating temperature, but the ATF level did not change, nor did it warm in the least.
I will pull the driveline because I can change the carrier bearing while I am at it.

I really appreciate all the help!

As soon as I can pinpoint the problem, I will be looking for the parts so I can get back on the road ASAP (this is my sole means of transportation)!

Stan

79Mercy · #27 05-20-2009, 10:26 AM

I would just find a good used transmission in your area and it put it in.

rs899 · #28 05-20-2009, 10:38 AM

If you need to pull the driveline to change the carrier bearing, have at it, but you would see motion if your tranny was working. The likelihood of catastrophic driveline failure without any prior noise or indication is low. The simple working pressure test I suggested will point you in the right direction on the tranny.

The 722.1xx TC has very slender "fingers" that like to shear off in the front pump. I bought my W116 300SD with that condition and there are other reports of this happening (after 30 years- go figure!) on this forum.

glowplugged · #29 05-20-2009, 11:02 AM

The only other clue the car is giving me is a slight change in RPMs when I put it in reverse.
No other selector position causes any change in RPMs.

I am leaning toward the front pump as the leading suspect.

I have been putting out my feelers for a used tranny around here, and have come up empty.

Stan

glowplugged · #30 05-20-2009, 11:56 AM

So, how much does that automatic weigh? It is looking like I will have to ship one quite a distance.

Stan