Automatic gearbox replacement 230SL

[Micker747]

I have bought another gearbox for my 230sl instead of fixing the old one. I think this is cheaper in the end.
I have checked thatbthe part number is the same.

does any of you have experience with this operation? any tips tricks and peculiarities appreciated! Thanks

Normally I work on Porsche and BMW so this is a bit unknown territory for me...

Mike

[merrill]

Mike
I R&R the transmission on my 230 several years ago.  I had the motor out, so it was easy.
if you do not have the motor out, a lift will be a great help,  do not forget about the access panel on the passenger side of the drive shaft tunnel.
it is under the carpet in the passenger compartment.

take good notes of wire an linkage connections.
also, only fill the transmission fluid a little at a time, if you fill too much it will over flow and end up on the garage floor.  its also a good time to replace the rubber drive shaft coupler between the transmission and drive shaft.

[ja17]

Helllo Mike,

Always dis-connect the torque converter before removal. It must come out with the transmission. The transmission front seal is an easy item to change while your at it, other  preventative repairs can also be taken. Replace the rubber transmission modulator diaphragm,gasket and small o-ring, also  the large o-ring around the front pump. These items are more complicated to change than the front seal. Only go there if you feel able.

If your converter has a riveted hub, pressure check it for leakage.

Lastly, make sure that the torque converter is fully engaged with the front pump before installation. Bolting the transmission up without having the converter completely engaged will ruin the front pump of the transmission.

Change the transmission filter and check to make sure that the lock nut on the reverse band adjustment is tight (exterior of the trans. right side).

If the old transmission was bad, flush the transmission fluid lines and the cooler built in the radiator otherwise you will circulate debris into the new transmission. The rubber transmission hoses are inexpensive, replace them if they are old and dry rotted. If you use your old converter flush it also.

[Micker747]

Thanks Matt and Joe,

I really appreciate your help.

So to sum up I will buy a fresh filter and the front seal, and probably keep it at that.
I will check and perhaps exersize the solenoid linkage and make sure it's free moving. I think the gearbox has been sitting for a while, so maybe I transfer the solenoid.
Is it easy to tell if the converter is properly engaged? Does it have a drain plug in it like newer Mercedes' does?
Finally, how much oil does it take? I assume it should be cycled thru the gears and level should be checked in Neutral, right?

Thanks in advance

Mike

[merrill]

Mike
hi,
yes the TQ has a drain plug.
sorry off hand I do not know how much fluid everything takes off hand.  check your uses manual or the tech forum.
to check the level I typically run the car thru the gears, including Reverse,  put in N for a few minutes and check.

there is a way to check the selenoid in the car, i will try to find it.
I will also try to find the install docs for the TQ. 

[merrill]

Mike
check this site out for some good tips.
these guys are very helpful and have rebuilt 2 trans for mw.

http://www.mercedesdismantlers.com/16BoltInstallationInstructions.html

[ja17]

The converter slides back into the transmission further than you expect. Keep rotating it and pressing it back until it moves back.   I like to grease the stub before sliding into the front pump. The cylindrical sleeve bearing in the front pump is soft metal and should be treated gently.

During installation of the transmission  torque converter should be able to be rotated before the converter attachment bots are installed. If the converter seems to bind-up as the transmission is bolted tight, then the converter is probably not all the way back and engaged.

I check to see that the converter is free and rotates as I am tightening  up the engine/trans bolts. Once the transmission is bolted up tight, the converter should be able to be rotated to align and attach it to the engine flex plate.

If the converter is not aligned and engaged in the transmission front pump, it will destron the cogs on the front pump as you tighten up the engine/trans bolts.   

[Micker747]

Thanks for all the help guys.

The "new" gearbox is in and working, however I have a few questions:

1. The new box did not have the two little solenoids or what is is on both sides, they were just plugged in the covers. (On L/R side front) I mounted the ones from the old box.

2. The gearbox number was the same, but the filters were different.

3. Downshifts are smoots, also 3-4 gear is ok, but 2-3 is very fast and a bit rough, even if I let go a bit of the gas, it makes no difference. I have tried turning the rod in / out a bit, about half-whole turn in each direction, but it doesn't do the trick. In the Installation guide from Sun Valley a vacuum line is mentioned to the gearbox, I have not seen such a line I believe!

I hope you can help me with these last snags.

Cheers
Mike