When you have the new engine and the old transmission out of the car connected together you can do a test-run before putting it back in the car.


connect the speedo cable to the tranny and the speedometer and run the engine to see if all the gears engage.


the most important thing to keep in mind when installing an automatic transmission to an engine is to ensure that the torque converter is fully seated in the front pump if it's not then you will damage the tc/front pump.
There is a tc/bellhousing distance listed in the manual for that.

vstech
 

vstech, I sent a message via the email option and then recently sent you a pm. Please advise.

Update:
First I hope vstech is ok. I have not heard from him.

I found an entire running drivetrain here locally. The donor car was a 300D with 143k original miles claimed. It was built 11/81 so an early turbo motor? It was totaled but driveable for testing. Zero visible blow-by(whatever that's worth) and compression of 27 bar/391 psi(x2), 29 bar/420 psi(x2) and 30 bar/435 psi. Other small signs suggesting accurate miles was the Behr radiator with the raised MB Star molded into the top, every sticker present including two on the fan shroud, and a perfect 10 interior. I'm trying to justify the $2900 for the motor and $900 for the trans but they are complete running plug and play + radiator + oil cooler. No cores so I keep my whole drivetrain.

I put value on the motor being complete and running as opposed to a stripped $1000 long block + $500 trans + $350 freight + 8.25% tax = $2000 with a "60 day hope it's good enough bc you might do everything twice guarantee." There was also alot of value in making progress. I know for a fact that when a main vehicle is dead for too long everything can get away from you. A month later you can't hold out any longer and you get a temporary replacement vehicle and now it's not urgent and a year later the car is still sitting. I figure I paid $1800 -$500 core = $1300 above the average rates but I was about to spend more than that on a beater car.

The interior of the donor car was off limits.

Progress Report
 

Sounds very good to me, please keep us posted and maybe some pictures of the job .

Sorry about pics. My motor had already been out of the car for a while and when I last posted at 4:00am the transplant was starting at daylight. Radiator out did allow the entire drivetrain to go in and out in one piece using a tilting engine hoist. Other than that you didn't miss anything very interesting.

The donor motor "works harder" and runs 15'F warmer. My only set reference is cruising speed. New motor is 70mph at 3500rpm. Old motor was 70mph at 3100rpm. Could some of that be the transmission? Temp difference could be an older vs newer sensor, different thermostats, different fans. I did use a smaller diameter 300SD water pump pulley and belts so it should have an advantage there. This motor does have the metal 6 blade fan. Old motor has plastic 9 blade fan. I need to research what can be mixed and matched. Now I'm constantly looking at the oil pressure gauge(with NOS MB oil lines) like an idiot.

My locked engine absolutely will not separate from the transmission so it's back surgery through the oil pan from what I understand.

Did the donor car have the same differential ratio?

Interesting
 

You'd maybe be surprised at what I find interesting .

Maybe a coolant flush in the near future ? .

Harbor Freight has pretty good $20 I.R. thermometers that will tell you the actual temps here and there on the engine .

I didn't feel safe driving the donor car at a sustained high speed so I don't have a reference. I can still check the diff. I only have info comparing each drivetrain in my vehicle/my same diff.

For temp differences I'll ohm the two senders for something obvious. After much research I will swap in the late 9 blade plastic fan still attached to a recently NOS late Behr fan clutch and plan to leave it in unless it somehow has an opposite effect.

Except for replacing the plug on the side of the overflow tank with a coolant level sensor and adding a low oil pressure alarm, all other existing parts will have to cover things for a few years in order to spread out this last maintenance bill.

The hose w/ double crimps on the ferrule looks like what I recall on my 1984 & 85 300D's. The one which blew off the tube might be after-market. I wonder how it pulled past the bulged end of the tube fitting. Pressure is only ~60 psig, about the same as a garden hose, so shouldn't take much to hold the hose secure. It isn't like the h.p. power steering hose (~1000 psig).

One of my cooler hoses was cut by the p.s. hose. The AC belt had broken and somehow flipped the p.s. belt over so it toothed end worked on the hose, plus sagged motor mounts. I replaced just the hose, using AC hose & ferrules, with a MasterCool crimper. Has worked fine for many years. You could use Oeticker stepless ear clamps if you don't have a ferrule crimper. Use long nail-puller pliers to crimp them (or the special tool ~$100).