Changing 300E Engine, Pull with Trans?
 

I need to replace a 300E engine. I have it on the lift with a chain fall above it. Will it be easier to leave the transmission in place or remove it with the engine?

I am about to get started on it, but between family commitments and Harvey disaster relief, it will be a while before I finish.

If you have done this one before, you can probably save me some time experimentig with different approaches.

My problem with pulling both is dealing with both out of the car. Working the bell housing bolts in the car is easier for me than trying to mate engine and transmission out of the car. I don't have a jig to hold the transmission steady out of the car. I can't count on another pair of hands.

Sixto
98 E320s sedan and wagon

I haven't pulled an engine on that car, but many others. Unless you have the equipment to raise and lower the engine and transmission as an assembly on the heavy angle required to get it in and out, I'd leave the transmission installed.
If the car will not have to be moved just block the transmission up in place. If the car will be moved then create a sling and suspend the transmission from strong points on the firewall.
Leaving the transmission in place saves working with the driveshaft, cooler lines, vacuum connection and electrical.
If the front pump seal leaks on the transmission that is the time to change it.
Good luck and keep us posted!!!

I’ve always pulled with trans. It’s nearly impossible to reach all those bell housing bolts with it in. Car needs to be jacked up slightly. Extra set of hands is very helpful but not a requirement if you have a load balancer

In my old shop I had a walking beam. In my new shop the chain fall is in an adjustable, but fixed location above the engine compartment, SO, if I leave the trans in the car I will have to build a sling or other support so I can move the car back to put the replacement engine on the chainfall. I do indeed have a load balancer.

When changing engines in the past I have always preferred to leave the transmission in the car. Sometimes it is necessary to pull it with the engine. I am curious if anyone familiar with the breed indicates that the engine won't fit through the engine compartment with trans still in place. I plan on pulling the radiator.

I’ve pulled 2 x the m103 out of a w124. I think with the radiator out you can possibly slide it forward enough to disengage it from the trans, but it definitely will be close

.... if you can actually get those top bell housing bolts off first.

I have done it the past. It's best to pull both together. It's not worth dealing with the hassles of disengaging the torque converter and then pulling the engine.

Once outside, you will have complete access to replace all the seals on the outside of the trans before putting it back in. Most seals/o-rings are are easy to change out.

I have also replaced just the tranny with the engine in the car and getting them aligned was harder than when I had both of them outside. I purchased a transmission jack and that did the trick.

I have a transmission Jack, but I really don't want to mess with pulling the transmission and THEN pulling the engine, but I will do what I have to do.

I spent a little time on it this afternoon, but it was hot in the shop. I leave in the morning. Won't be back until a week from Monday, so I will get back into it then. Meanwhile thanks for sharing experience and comments. Please keep them coming.

IMHO
It's much easier using an engine leveler and pulling both out. Remove radiator.

One time I didn't have a leveler, was operating in a shop with limited ceiling space. Raised the rear up slightly and when angling the engine out, removed the front wheels, supported the front end on a floor jack and lowered the front as close to the ground as possible - just had enough room.

Lying on your back getting the transmission off while everything is still in the car is no fun.
If you have a hoist obviously disconnecting the transmission left in the car is easier.

remove rad and condenser, buy a engine leveler then pull both at same time

I have pulled it, better to do it with the transmission, removing those top bolts is not fun. And MB do a fantastic job with wiring too, even with the newer complex cars, its usually just one or two giant plugs. On the 103 its pretty simple itself.

once the radiator and fan is out, lots of room to tilt the powerpack, Just need to raise the car. On a W210 I have pulled out a M112 without the trans as you can literally see and touch the transmission bell bolts from the engine room. To be honest, it would have been better with trans as there is a ton and a half engine room in a W210 with a v6

If you pull the center part of the "firewall" in front of the blower motor you can access the top transmission bolts
It is a big help when working on the 190. I pulled a w124 engine with the transmission and it sucked
I really do not suggest doing it that way.

Even though there are different approaches favored by different people, this is developing into a good thread.

When I get back home I am going to see how hard it is to pull the forward firewall before making up my mind.

I have the car on my two post lift with a chainfall over the engine compartment. I do indeed have a load balancer.