Conversion Problem. Need help.

Walter Buller · Jul 19, 2012

We are putting a 1993 5.9 12v Cummins with an NV 4500 tranny into a Chevy 3500 that originally had a 6.5 in it with an automatic. We had to use a 1994 clutch pack and flywheel because the bell housing is off of a 1994 Cummins. The problem we are having is the inside of the bell housing binding on the pressure plate before the bell housing is flush against the motor. We have tried 1993 clutches, but the same thing happens. The bell housing is now able to touch the motor at the bottom, but stands away from it just a little at the top. We speculated that there may be some kind of an adapter plate that goes there but the Chrysler people didn't say so. Do any of you guys have any idea of what the problem might be?

showcrop · Jul 20, 2012

It sounds like there must be a difference in the shape of either the crank flange or the flywheel, so that the pressure plate is positioned slightly further away from the block. It shouldn't be difficult to get the flywheel surfaced to allow for more room. I converted a clutch to a double disc which required getting a different flywheel and getting it machined to have room for the additional clutch disc and "floater" disc. It was just a matter of measurements. Assuming it is a standard transmission you will need to do the same type of measuring to have your clutch fingers at the proper height for the release bearing to engage properly.

scotc · Jul 20, 2012

The issue is the flywheel housing. The 94-up unit is deeper than the 93-earlier unit to allow more room between the flywheel and transmission for the lock-up torque converter in the automatics. You need the flywheel housing and starter off a 94-up unit, as the starter is different as well and the earlier starter won't engage the flywheel properly when used with the later flywheel housing.
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Conversion Problem. Need help.

Walter Buller

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showcrop

Well-known Member

scotc

Well-known Member

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