Just removed the trans from the engine. As I had the engine/trans assy halfway removed from the car, and had it tilted, oil came out from the top of the trans, and I believe the source was the slotted hole (see picture below). I had just purchased this car and someone (jiffy lube) had waaaaay over-serviced the oil, to the point that it smoked extremely badly and lost a lot of power. Once I drained it to the appropriate level it behaved beautifully and didn't smoke. Yaay.


Second question: how do I get the bell housing off? Just get a big pry bar and pop it off? I don't see any bolts..

The convertor housing, aka, "bell" housing is integral with the transmission case. If the question is about the intermediate plate on the back of the engine (where you are pointing in the pic), leave it on the engine. It serves as a centering device for the transmission, as well as a point of attachment for the trans. It will be required to attach the engine to the next transmission. If it is removed, it will have to be re-centered to the engine. You do not see the bolts because they are hidden by the flywheel

The intermediate plate on my OM617 was off when I got the engine. I'm getting close to finishing up my it's my rebuild, do I need a special tool to center it back up? From what I could see, the bolt holes were not slotted or anything. Seemed like it just bolts up to the block.

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Milan Brown 1979 240D, rebuilt OM617.952 turbo diesel, rebuilt 722.315 transmission - engine spun a rod bearing, sold to pick your part

1979 300SD, ~90k original miles, all stock

I’m replacing it with a manual transmission

I think you need an alignment shaft from what I remember. From my limited knowledge sometimes you can buy the tool or you can just gut an old transmission.

What part of "next" is causing difficulty?

An examination of the back face of the intermediate plate (IP) will reveal a circular recess of about 12 5/8" diameter. There are gaps in the circle in a few places, but it is circular. By mounting a dial indicator to the crankshaft so that the tip of the indicator touches the OD of the circular recess, and rotating the crankshaft, the run-out of the recess relative to the crankshaft can be measured. With the IP bolts slightly loose, it can be tapped into concentricity with the crankshaft, and the bolts then tightened.
Once the IP is centered it will center any transmission that is bolted to it.

Thank you Frank. Glad to have this information.

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Milan Brown 1979 240D, rebuilt OM617.952 turbo diesel, rebuilt 722.315 transmission - engine spun a rod bearing, sold to pick your part

1979 300SD, ~90k original miles, all stock

Oil was in the groove due to an oil leak ( valve cover ). Oil entered to the right / above the slot. You can see a black area where the transmission does not completely cover the slot but farther down / to the left the transmission more or less covers the slot.


Remove the torque converter and flex plate, there should be a few bolts holding the intermediate plate on. While I don't know this engine specifically, I have never run across a modern ( 60's + ) production engine where the intermediate plate / bell housing needs indicated. Good design / manufacturing practice dictates dowel pins or sleeves.

Also, it is always better to unbolt the torque converter and leave it in the transmission rather than deal with fluid spills , physical gyrations to get the engine away and out of the trans. Leaving the converter in only requires about 2 inches of movement Vs 8+ with the converter bolted to the engine.

. . .And, if you try to install an engine with the converter bolted to it, it will take much effort to get it close and likely break the converter hub / pump gear first time the engine is cranked.

Technically Frank is correct regarding the use of a dial indicator. On a new, clean engine this is the proper way to initially install the intermediate plate.

On an engine which has been in operation for a few thousand miles, unless you do a super clean-up job on the block and plate this is not practical. Normal flexing, scads of gunk and a gadzillion starts will deform the metal enough to negate the precision.

I go with string stretched across four bolts to create an "X" and "eye-ball" it. Not the most scientific but it has served me well.

You have plenty of "slop/tolerance" with an auto-box but since you are converting to a manual then I'd suggest taking Frank's advice.

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“Whatever story you're telling, it will be more interesting if, at the end you add, "and then everything burst into flames.”
― Brian P. Cleary, You Oughta Know By Now

So these engines don't have dowels between the block and plate? How about between the plate and transmission? No dowels = centering manually is a must.

Also if no dowels, it is sounding like the plate was bolted to the block before drilling the bell housing holes / pin locations.


Actually alignment with an auto is more critical than a manual. The converter front is piloted to the crank with the pump bushing on the other side. There is near zero axial clearance at the crank pilot and only a few thousands of an inch on the pump bushing side. While the flex plate takes care of some angularity misalignment, it does nothing for concentricity issues.

With a manual trans clutch, there is a fair amount of free play on the splines and the clutch disc's center is somewhat free floating taking up axial and concentricity issues.

I'd enjoy a discussion regarding GD&T with you and also the misconceived notion of having a "floating" clutch disc at 5K RPM's but it doesn't address the the original poster's problem/question. Let's help him with his request.

__________________
“Whatever story you're telling, it will be more interesting if, at the end you add, "and then everything burst into flames.”
― Brian P. Cleary, You Oughta Know By Now

Indeed, indeed!

Well as long as someone is learning something, it’s all in good fun.

The entire disc does not float, just the splined center hub. The next time you have hands on a spring center clutch disc, push the center around. There will be some axial movement that takes up minor miss alignment. A solid center disc lacks this free play and this contributes to spline wear.

Regardless, an auto trans is much less tolerant of concentricity miss alignment and will end up with a damaged pump bushing. This is because you only have a very limited amount if clearance at the bushing and lack of axial flex in the system.


I won't let bad info stand. What would help our guy is a posting of the actual factory procedure to align the plate.