I'm in the middle of building up the new OM603.960 3.0 engine, using many of the 3.5 engine parts.

First question- is there anyone who has done this and used the 3.5 litre flywheel? I am using the 3.0 litre flywheel, so no worries there but the 3.5 flywheel is radically different, and much lighter. Just wondering what experience anyone may have had running the 3.5 flywheel.

Second- The windage tray from the 3.5.

I am using the oil pump and pan from the 3.5, and so am installing the windage tray. I know that tray screws can work lose and get sucked up by the oil pump. Will Loctite be sufficient to prevent this? My original 3.5 had this happen, and I don't want that happening again!

Thanks

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Chief

1991 350SD

When I did this a few weeks ago I used the oil pan off of the 350 but did not move the windage tray. I kinda wish I had used the original pan off of the 300 just for the added capacity. I did not see any difference in the operation of the engine without the windage tray. Also, I'm not sure if the crank bearing caps from the 300 have the holes for the windage tray fasteners. Blue locktite should be fine on anything you bolt together in there. Make sure you torque to spec.

I think it would be an interesting experiment to try running the lighter flywheel. With that said unless if you have access to an engine dyno it would make it alot easier to try it.

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Jim

Hi Jim, I remember reading your thread on that swap.

I don't think (not 100% sure) that there is a capacity difference btw the oil pans. I though that too, and like the idea of having the side sump access, but I am using the timing cover from the 3.5 and the dipstick is right for that oil pan. Didn't think about the mounting screw holes- I'll have to look and see what I have when back at the shop today.

I'd like to run the lighter flywheel, but I don't have the opportunity to experiement.

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Chief

1991 350SD

If I ever hit the lottery one of the items I'd like to have in the shop is an engine dyno.

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Jim

Okay, maybe I'm being a bit OCD about the flywheel, but this is one of those things I want to get right!

As stated before, I am using the .960 flywheel on the .960 engine. Seems simple enough, right?

The .960 is the solid flywheel, with the flex plate interposed between flywheel and torque converter. This engine came from a non-MB installation and had some kind of hub also bolted to the crank. The .970 wheel is simply a "hoop" or ring, with the flex plate riveted to the rim. On removal, I found that the flywheel bolts also pass thru a hub plate first, then the flex plate and into the crank hub.

First question:

SHould I also use this hub plate on the .960 flywheel? That would have the bolts passing thru 3 layers, rather than 2. If I trial fit the hub plate, it does not engage the locating pin on the crank, as that distance is taken up by the thickness of the flywheel and flexplate. I am inclined to think not, but since the .960 engine had that hub attached, I don't know what was there originally.

Second question:

Where is the sensor trigger on the flywheel(s)? The pickup is in the same place on both pans, but I can't find the trigger on either flywheel.

I'm ready to put the short block back in the car, but not until I get this figures out!

Thanks!

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Chief

1991 350SD

An offline discussion with Jim (Engatwork) resolved my concerns here. For the benefit of anyone else that would like to know, here are the answers.

The 3.0, .960 engine does not need the hub plate.

The pickup apparently reads the ring gear teeth, so nothing is missing from my flywheels.

Engine is ready to go back in the car.

Thanks Jim!!!

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Chief

1991 350SD