NV4500 clunk

[Itali83]

I had an nv4500 in my Cummins dodge. Had the same sound but it was from a worn rear end with too much backlash. I just dealt with it but I’d check the rear end too. Sound travels up a driveline like crazy sometimes.
Ben.

 

[Frankenchevy]

I had an nv4500 in my Cummins dodge. Had the same sound but it was from a worn rear end with too much backlash. I just dealt with it but I’d check the rear end too. Sound travels up a driveline like crazy sometimes.
Ben.

Both my 14ff and d60 were both rebuilt less than 50 miles ago and my driveshaft is brand new as well. Everything was done at the most reputable axle shop around.

You’re right though, in person it sounds exactly like automatic transmission driveline clunk. Like when you shift from park on a hill without the parking brake or the clunk you get from R to D.

 

[DoubleDingo]

I'm with Andy on this one. Run it like they said. They're sending a new one anyways.

 

[Frankenchevy]

I’m worried that if when clunking it’s ramming into the pilot, it’ll damage the thrust bearings on my crankshaft.

 

[bucket]

I’m worried that if when clunking it’s ramming into the pilot, it’ll damage the thrust bearings on my crankshaft.

I'm no expert, but I don't think that's at all possible?

Again, I'd just drive it and use it as much as possible. It will either stay the same, or the real problem will present itself and it will be obvious what needs dealt with.

 

[Frankenchevy]

I'm no expert, but I don't think that's at all possible?

Again, I'd just drive it and use it as much as possible. It will either stay the same, or the real problem will present itself and it will be obvious what needs dealt with.

I’ll try driving it again this weekend after I do the lift. I have some u bolts removed right now so I can pick up the right length ones tomorrow. Need shorter ones for the rear and longer ones for the front.

 

[DoubleDingo]

I highly doubt a rotational clunk within a closed case will cause any thrust issues on either end of the unit.

 

[Frankenchevy]

One thing that popped into my head that I’ll look at when I get home...

In this incredible CAD drawing, the gray bit is my bushing. As you can see in the photo below, the bushing is taller than the gold zinc metal piece. So even if I torque the bolts pretty tight, perhaps those ridges may be responsible for some extra movement.

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I might try pulling them out and cutting them off.

 

[DoubleDingo]

You may be onto something.

 

[Frankenchevy]

@SquareRoot , is there any way you can get a straight edge or a 2x4 across the bottom of your frame rails and measure up to the mounting points on your nv4500? I’m wondering if my mounts+my 4x4 steel block is too high...

 

[Frankenchevy]

I’m starting to think it may be the Detroit locker causing the clunking. My driveway has a slight incline so I can point the nose downhill, put the truck in 4wd, pull the rear driveshaft and back up it for a test. If that’s what it is, I may be shopping for an ARB...

I think the th400 was just better at making the clunk softer...I guess

 

[SquareRoot]

@SquareRoot , is there any way you can get a straight edge or a 2x4 across the bottom of your frame rails and measure up to the mounting points on your nv4500? I’m wondering if my mounts+my 4x4 steel block is too high...

I can but I think mine is different from yours. I got a K20 frame with K30 running gear.

 

[DoubleDingo]

I’m starting to think it may be the Detroit locker causing the clunking. My driveway has a slight incline so I can point the nose downhill, put the truck in 4wd, pull the rear driveshaft and back up it for a test. If that’s what it is, I may be shopping for an ARB...

I think the th400 was just better at making the clunk softer...I guess

The slop I mentioned

 

[Frankenchevy]

I can but I think mine is different from yours. I got a K20 frame with K30 running gear.

True. I figured the rise of the crossmember from the bottom flange of the frame wouldn’t change though. I could be wrong, but I thought a W crossmember would be the same on a k20 and k30.

 

[SquareRoot]

True. I figured the rise of the crossmember from the bottom flange of the frame wouldn’t change though. I could be wrong, but I thought a W crossmember would be the same on a k20 and k30.

I'll get the measurement in the morning.