1977 mercedes 280e transmission removal

[mikes]

Is there a thread that details the step by step automatic transmission removal from M110 engine? I have done a few searches with no luck? Thx inadvance

[cth350]

pretty straight forward for just about every benz automatic....

Just remember to keep things were transmission fluid comes/goes from getting any dirt, lint, etc into the trans.

- Disconnect both leads on the battery. You'll be disconnecting the starter, so this is essential to keep the car from catching fire. (so yeah, do it first).
- Remove the exhaust. Annoying, but essential because it's in the way.
- Disconnect the drive shaft. Leave the rubber donut on the part staying with car usually (the drive shaft in this case). Disregard that advice if you're installing a new one.
- Drain the torque converter. As you hand crank the motor, you'll find an in-hex socket that takes a 6mm allen key. Just point it down and remove it. Catch the 1+ pint of fluid that comes out. Turn the crank with the socket correct for the bolt on your crank (should be 27mm).
- Undo the three pairs of bolts that hold the torque converter to the driven plate. There is an access panel at the bottom of the engine that comes off.
- disconnect the fill tube. There is a small bolt towards the top that holds that end down. The other end is big hollow bolt with a pair of reusable crush washers. Catch the 1+ quart of fluid that should come out.
- Either drop the pan and drain all the fluid or plug the hole from the banjo bolt with a piece of lint-free rag (the stuff you use to wash a car) to minimize further fluid loss. Another way to do it is get about 1/2" of heater hose that fits on the banjo bolt and let it seal the bolt holes when you screw it back in the pan.
- disconnect the metal cooler lines. Plug the holes & lines to keep dirt out. Only a small amount of fluid will emerge.
- Disconnect the wires & shifter. For your transmission, there should be one wire on the opposite side from the shifter. The neutral safety switch wiring on yours is a single plug with four wires. The metal rod to the shifter is held in with a clip into a plastic bushing. Remove the clip, pop out the rod. That 1$ bushing disintegrates after a few decades (clearly a cheap part). You probably want to replace it on reassembly.
- Undo the bolts that hold the transmission to the block. You'll find that you can see them all if you're under the car by the drive shaft. You'll need a really long extension rod and universal joint.
-- The upper bolt on the starter is the pesky one; do it first. It should be a 10mm allen key.
-- Keep an easy one for last. Before you remove it, put a jack under the pan.

Here comes the fun part. That transmission is about 100 pounds. You need to let it down slowly. You want the torque converter to stay with the transmission.

To remove the torque converter, hold the transmission so the torque converter points up. Then remove it. Do the same when you put it back (and with a fresh seal). The torque converter is heavy enough and the snout sharp enough to destroy the seal if you don't do it that way. On reassembly, ensure that the torque converter is fully engaged on the teeth of the input shaft. Also, ensure that the teeth on the input shaft are intact. They can get sheered out if not assembled correctly.

HTH -CTH
PS. So why are you pulling the trans?

[mikes]

Are you sure there is an access panel on the m110 engine to access those torque converter bolts? I had a look but I didn't see any access panel there.


I am pulling the m110 engine and transmission because I think I have a leaking rear main seal on my 1985 280ge which is causing the clutch to slip. I am hoping to swap m110engines because its a rear PITA to replace the rope type rear main seal. The oil leak my also be coming from the transmission input shaft--.I won't know which seal is acting up till I get it apart.. Is there an easy way to determine which seal is leaking. I'm anticipating oil being thrown around by the centrifugal force. Will UV die detector work?

[Frank Reiner]

mikes:

Yes, there is an access cover for the convertor bolts. It is a sheet steel piece on the front of the intermediate plate.

Before putting a lot of effort into changing engines, put effort into determining the source of the oil on the clutch. The shape of the flywheel is somewhat dish-like, with the clutch inside the dish. As a consequence, engine oil has a rather difficult path to travel to reach the clutch, its origin being at the outside center of that dish. By contrast, oil from the gearbox is carried through the release bearing guide tube, and enters the clutch at the inside center.

The suggestion would be to first remove the gearbox and carefully inspect the inside of the guide tube for the gearbox lube (ATF). Should you be convinced that the tube is dry, and that the seal is not leaking, then remove the access cover from the front of the intermediate plate, and examine the front face of the flywheel for engine oil. Because of the shape of the flywheel, copious amounts of engine oil have to leak and be carried into the clutch housing, where it can eventually drip from the inside of the housing, and find its way through the dust vent holes in the flywheel rim to the friction surfaces. The amount of engine oil required will leave a puddle wherever the vehicle is parked, and the underside will be liberally coated. But only a very small amount of gearbox oil is sufficient to cause a slipping clutch.

[mikes]

I found the access cover. It is a screw type fitting. A #22 socket fits into it. I will look for the tranny leaking possibility when I have the tranny separated.
Is it difficult to replace the input shaft seal on a 5spd transmission?