flywheel clutch confusion

[MunK]

Ok here is what I have... I tore apart two trucks this weekend...one is a 1992 D350 2x4/getrag and the other is a 1990 4x4 with a NV4500 swapped in using an Advance Adapters bell housing.

My issue...both have the same pressure plate "SACHS" (the same casting #) but the Nv4500 truck has a 12.5" clutch (LuK)
The Getrag truck looks to be OEM SACHS pressure plate and disk 13"...Now here it gets even more confusing.

The flywheel off the 1990 NV4500 truck is lighter (lots) than the 1992's....so in an effort to get this running eventually I need to know which flywheel should I use? Laying on the floor they seem to be within 1/32" of being identical on the ring gear and the surface area, maybe even closer.... help?

added note: The 1990 trucks clutch never seemed to have enough travel...disengagement was almost on the floor. Also the 1990's clutch has like 4000 miles on it, so it wasn't worn out.

I am tempted to use the new Sachs pressure plate off the 1990 truck and go buy a new Sachs Disk and install it with the 1992's heavier flywheel...but I am wondering why the MUCH lighter flywheel in the 1990....did Dodge use different ones?

[nooblet]

Ok, what exactly are you trying to accomplish? Are you using the NV4500 I take it? Are you swapping it into the '92? Or are you just replacing the clutch in the '90? Your mixing up all these parts, but you haven't really said what your end goal is.

Chris

[MunK]

Chris...

I am tossing the 1990's Nv4500/205 and the 1992's Cummins into a 1985 W350 Crew Cab Short box.

The clutch, pressure plate, flywheel, and the Nv 4500 from the 1990 all are brand new as of 4000 miles ago.

The 1992 D350 I stole the engine from has 107K on it and "should" be all OEM.


What I am trying to determine is if there is any reason I would "have" to use the lighter flywheel with the Nv4500/Advance Adapters bell housing. If not I would prefer the 1992's heavier flywheel.


NoRM

[nooblet]

If the bolt holes on your flywheel line up with your engine and your clutches are both the same size I don't see why you couldn't swap flywheels. I have very limited experience with NV4500s, but from what I've been told the clutches are pretty much the same.

When I ordered my clutch/flywheel/pressure plate the guys told me its the same setup they would have sent if i was running a NV4500. I asked them if it would swap over because I eventually plan on going with the new venture transmission at some point.

They just drilled two sets of holes in all their stuff so you could use them with either transmission.

Thats why I say if the bolts line up you shouldn't have any problems.

Let us know how it turns out.

Chris

[KTA]

The original flywheel has a step on the clutch surface side where thepressure plate mounts. If you are going to use the Sachs cover I would use the original flywheel, if you are going to a newer replacment clutch I would use the newer style flat flywheel. It maybe that you have to use it to clear the clutch fork on the advanced adapters kit, I am not sure what allowances they made when building those kits. If you mix and match you could wind up with some clearance problems.

[MunK]

Thanks guys... I am at this point going to just test fit the mess on the bench and see what the deal is.

KTA: This step you refer to....I assume it's on the face of the flywheel?

I was under the opinion from the PO that my 1992 had never had a clutch...that said the flywheel is flat LOL

The flywheel I removed from the NV 4500 truck is half the weight of the one from the Getrag truck...both are in great shape so...I will try the heavy one and see if it all fits.

[KTA]

There is a stepped kind of lip all the way at the edge of the flywheel around the OD.

[MunK]

Thanks KTA... I just looked, it's stepped as you described.

Looking at Advance Adapters web page and pdf files they claim you can reuse the clutch, throwout bearing, clutch fork, and slave from the getrag.

So we shall try unless sum one can suggest a reason to use a MUCH lighter flywheel.

I may actually get this project done yet

[KTA]

A lighter flywheel is good for more RPM without exploding.

[PToombs]

It will wind quicker too, less rotating mass.

[PToombs]

MunK, how'd you do with this? I may be swapping clutches around soon, and am curious about your results.