1986 300SDL Transmission Removal - PeachParts Mercedes-Benz Forum

obmaj · #1 11-08-2008, 07:53 PM

I believe I have a front seal leak on my transmission. Leaks when topped off and stops leaking just when it starts to slip and not shift. Fill it back up and everything is fine, except the mess. I am planning on removing the transmission, replacing the seal, and reinstalling (can't afford to replace). Car has 205K miles, in great shape.

Just looking for help in removing. Have removed a few transmissions before, just never a MB. Ant help would be appreciated.

Thank you in advance for any suggestions.

Oracle12345 · #2 11-08-2008, 07:56 PM

You will have to remove the transmission with the engine. So make the necessary disconnects and drain appriotate fluids.

blindwolf · #3 11-08-2008, 10:05 PM

Why does the transmission need to pulled with the engine as an unit?

sixto · #4 11-08-2008, 10:35 PM

There's a bit of work involved -

1) Detatch downpipe from turbo, remove exhaust rubber hangers, drop exhaust

2) Remove driveshaft shield

3) Remove driveshaft, support each segment so you don't bend the CV joint more than it bends while attached to the car, transmission and differential

4) Finally get to the transmission. Mind the engine rpm sensor behind the oil filter housing. There are 6 bolts that take a 5mm or 6mm hex bit holding the torque converter to the flex plate. As you turn the engine CW only(!) the bolts will appear in pairs in the oval port at the bottom front of the bell housing. Might be worth marking the alignment of the torque converter and flex plate. When the torque converter is free, push it back into the transmission. There's provision for a locking key on the driver side of the bell housing so the torque converter doesn't fall out if you tilt the bell housing down. You can probably find a bolt or something to use instead of the key. Some bell housing bolts are easier to reach from above.

Aside from seals, there's also the B2 piston, K1 spring kit and a shift improving spring kit available. These things aren't difficult to replace with the transmission in place but maybe you don't like working on your back with ATF dripping on your face.

Sixto
87 300D

sixto · #5 11-08-2008, 10:39 PM

Oh yes, good time to check the driveshaft carrier bearing.

Sixto
87 300D

Oracle12345 · #6 11-08-2008, 11:05 PM

Quote:

Originally Posted by blindwolf

Why does the transmission need to pulled with the engine as an unit?

Just easier when it comes to reinstalling. Theres enough room in the engine compartment to do it.

Fortunately for w126 you have a lot more room in terms of reaching the tranny bolts but on other mercedes there isnt much room and removing engine and tranny as a unit is just plain smarter.

If you want spend less time i would pull the motor and tranny together.

mplafleur · #7 11-09-2008, 07:00 AM

I am about to install a rebuilt trans and engine into my SDL. I was thinking about putting the trans in first and then installing the engine. It's just that both as a unit are sooooooo long and heavy that I thought that it maay make more sense to do it in steps.

Comments?

Oracle12345 · #8 11-09-2008, 09:24 AM

Quote:

Originally Posted by mplafleur

I am about to install a rebuilt trans and engine into my SDL. I was thinking about putting the trans in first and then installing the engine. It's just that both as a unit are sooooooo long and heavy that I thought that it maay make more sense to do it in steps.

Comments?

Dont use an hydraulic engine hoist because you will never be able to put engine and tranny as a unit. I use a home made gaintry crane which makes putting the engine and tranny as unit so much easier.

My gaintry crane is made out of 2 steel columns with heavy steel plates as a base. On the top is a thick steel bar that can support the wait of the engine and tranny. Ive used it many times and no troubles at all. hasnt toppled over at all. you can also push the car back to aid in unistalling. Use a chain hoist too.

mplafleur · #9 11-11-2008, 04:37 AM

Now I just need to find a 1000 lb chain falls.

charmalu · #10 11-11-2008, 09:56 AM

If I had to replace the automatic transmission, I would also pull the engine and trans as a unit.

I replaced my engine last year and pulled both together. I used an engine hoist with a eng. tilter. had rear of car up on blocks, and the front on jack stands.

the only challenge I had was the hoist only went up so high, the engine would not quite clear the radiator support. so used my 2 hyd. jacks and raised the car to remove the jack stands. then lowered the car down and everything cleared and rolled the hoist back from the car.

those damn little casters on the eng. hoist do not want to roll on rough asphalt with the weight of the eng. on them. I had 2 long pieces of flat steel about 10 ft long I slid under the front of the car to roll the hoist on. smooth as butter then.

that automatic is one heavy sucker, and I don`t have a trans jack, and also would have had to jack the car up higher to get clearance to be able to roll the trans out.

replacing a 4 spd manual, piece of cake leaving the eng. in. can do it one handed.

a gantry crain with a chain hoist is the ideal way to do it. Harbor freight has one for $600.00.

a nice warm shop with a lift would be ideal too

.

thats my 2¢ worth.

Charlie

mplafleur · #11 11-12-2008, 07:28 AM

Quote:

Originally Posted by charmalu

replacing a 4 spd manual, piece of cake leaving the eng. in. can do it one handed.Charlie

Good. Come over and finish the one on my 240D. I've now got the engine in, but couldn't slip it on to the tranny. So I took the tranny out. Except there's still a cable attached. The speedo I guess.

How does it come off? I'm in China right now and can't look at it, but it's what I have to do when I get back home.