Nv4500 cracked case

In the last few years, I've had 1 customer with a cracked case and it was due to not seating the U-joint clips. Now, in the last week I've had 2 customers return with cracked cases. Both, have had a rebuilt nb4500 installed by me. I'm starting to question myself......... One is a first gen that ended up having driveline vibration, should have never let it leave. Customer said it had been like that, I suggested taking it to a driveline shop to get it fixed. My fault, so now it's being fixed right.
2nd truck I haven't got in the shop, yet. Customer says they found a crack toward the top (guessing it's the same place as usual) Just your typical 2nd gen 4wd. We had the NV rebuilt a month or so ago, and had the t-case gone thru. It drove perfect. No vibration, no leaks, etc.
Anybody have some input?


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Never seen this, personally.
What's the chances either dropped a rear driveshaft previously?

Mark.

drivers side close to top on the top bell housing bolt

The first gen definitely had a bent driveline. We just got it repaired. That truck prob hasn't driven 150 easy miles since the rebuild, and the case cracked that quick.

This second gen, I'll get checked out today and see what's up.

I had a buddy crack 2 or 3 getrags and then 2 nv4500s trying to be a drag racer with his 1st gen. I bet he also had some mount issues letting stuff move further than it should.

We have one laying in the building I plan to have welded, rebuild and install in brother's puller. It had a broken input. Front bearing has been extremely hot. My guess on this one is front bearing locked up, broke input and cracked housing.

I also now own the truck that the trans came out of. It does have quite a bit of movement and has been beat on.

Maybe they were already there? once I cleaned and light grit air sanded the whole outer case I found probably 5 separate cracks. my case has been through a lot and will be retired the next time it comes out.

Me personally and some people I know have had and still have issues with the rubber mount under the transfer case coming loose or wallering the mount holes and you can move it quite a bit.

A new case is like $300, might as well imo.

Bad Trans mount and good motor mount leads to the driver side bell housing upper bolt area to Crack.