I have a problem with the Trans in my 1983 280SL, sometimes when I first start to drive it seems like the car is stuck in low gear. After I stop and go two or three times it starts shifting normal again. Some times I will put it in "L" and drive about two blocks and then put it back into "D" and it will start working. The only time I have noticed this problem is when I go to drive the car after it has been parked for some time.

I had the filter and fluid changed last week the old fluid look perrty good. The records indicate that it had been changed 6-17-02 also many of the orings were replaced ( T/F kit, Mod/cap, F/pump seal/Oring, kick/dn oring, mod/oring, gov/oring, dip/st/oring, speedo/oring, reg/oring, cap, teflon/rings). The repair order said it was brought in for steam from underneath the car. It costed the the previos owner about $700.00.

Sounds like a valve body problem.

I have fixed a few by loosening the bolts and precisely retorquing them. A good additive designed to remove varnish can sometimes free a valve that sticks when cold.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

brownae, please describe the speedo suddenly working after it finally starts to shift.

The speedo merter stays at zero MPH even though the car is moving, but when the car get to about 15 or 20 MPH the meter starts working. I not sure if the two problems are related or I have two different problems.

That's a different story. If the speedo also doesn't work when the car doesn't shift, the output flange nut is loose.

With it loose the governor and speedo gear spin freely on the output shaft (they are not keyed they are held tight by the torquing of the output flange nut) and without governor spinning there will be no shifting.

Pull the driveshaft down and tighten the nut.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

Thank you Steve. My hats off to you.
All the technical manuals in the world can't produce (without hours of searching, maybe) what you just came up with in just a moment.
You have saved brownae a lot of money and headache. Hey brownae, we are in the presense of greatness here!
Pay up Brownae. You owe steve big time.

You are right bmunse, Stevebfl has saved the day "checks in the mail". I will let everone know how it turns out. Where can I find the engin number?

The engine number is on the block at the left fron corner of the engine. Just under the intake on a machined section. It starts off with 110

Thank you bmunse your help has been great.

First I checked the modulator, it tested good. Then I pulled the black cap off of the modulator, made a slight adjustment and then replaced the cap. Making the ajustment fixed the cars trans problem. Thanks to everone for their help, the information that you provided helped me to zero in on the problem.

Has anyone tried using laquer thinner to cause seals to swell up and stop leaking? I heard this was a trick from a Aamco tranny guy to make the seals last a while before replacing them.

I have not heard of using lacquer thinner before. I would think that since it is such an agressive solvent, that it could really cause some problems.
Brake fluid was the trick that I have heard of and used before. I believe that it may work in some cases. There are a bunch of snake oil type trany rebuilds in a can on the shelves out there.
If you have a transmission that is older and has soem potentially hardened seals, then if you pour something in that could soften a seal and make it seal better than some short term help would be achieved. Nothing works as well as replacing the seal.

Hey brownae,
Did you tighten the flange nut? Your not mentioning it makes me ask the question. Becuae of stevbfl's answer, it HAS to be loose.

No, the modulator was the first thing I checked. My plan was to try one thing at a time an perform a road test after each event. When I road tested the car After testing and adjusting the modulator the car performed so well, it was very clear that no more checking was needed. I have been driving the car for about three and a half days with out no signs of the trans not shifting. The speedo seems to be working fine to.

Steves response made complete sense. I fear that you are experiencing a short respite from the problem. A speedometer not working and then jumping up to 20 is not normal. When you add that it also hadn't shifted then you can see how that nut must be loose. Four bolts to remove the driveshaft from the flange(You may have to remove from the diff too, but Steve didn't say so) then stick asocket on an impact wrench and tighten things up. Good insurance and 1/2 hour tops invested.