Why you don't re-use your u-bolts
 

Truck had been "shifting" and making a weird left movement lately when braking hard. So while I was under there welding a new cab mount I looked at the front axle and noticed 2 of the u-bolt nuts weren't even tight. I could see an air gap between nut and axle

Anyways, looks like the prior owner re-used the u-bolts. And the threads rolled or something.Hard to see, but the nut would run up until resistance. Then it would pop and slip down. Scares the hell out of me that I drove with it like that.

Replaced with these. Says are for a 99-04 truck, but they are same dimensions.So yeah. Be careful out there

Old u-bolts can be a problem. However, those on Dad's truck were in excellent condition. Here's a shot of them after powder-coating:

https://cimg2.ibsrv.net/gimg/www.for...b7af0e5cf7.jpg

It's a good practice to check the torque after several hundred miles, too.

My front U-bolts are a lot flatter on the top. Are those bolts meant for a 1999-2001 model year (i.e. is that what "info on box" says)?

U bolt threads are cut differently than normal bolts. The threads are pointed, more like the top of a triangle. This is designed so that once tightened it deforms the thread and does not allow them to come loose. You should always use new u-botls or you chance them coming loose.

Your U-bolts are in backwards.
look at the other photos.....

Yup. Those on Big Blue are flattops as well:
https://cimg0.ibsrv.net/gimg/www.for...86cffd7516.jpg

Can you find something on the web to back that up? I can't find it here and have never heard of that before.

http://www.clampsinc.com/pdf/guideli...olt-design.pdf

There are three main types, round, half round, and square. Important to use the right type. Nobody will mistake a round for a half round, but half round and square won't interchange.

Threads are cold rolled, nut cut. They do tend to deform when removed and are often so corroded or rusty it's not going to happen anyway. Lots of folks re-use them successfully but strictly speaking they are supposed to be a one time use. Maybe the U-bolt folks are just scamming us.

Never heard that before either; my chief concern with reusing u-bolts would be any kind of stretching they have endured, causing increased fatigue and eventual failure. I've seen it first hand on reused headbolts (not studs). Are these u-bolts subject to similar stresses where they could fatigue and eventually give out? Composition and manufacturing processes certainly play a role too.

Gary Lewis
Is that a factory differential breather, or something you added?
Looks like a good idea!

Something I added. It is a metal fuel filter I had painted black, with the hose run through existing holes in the frame.

The only problem here is that your truck is too clean :)

You mean the fact that everything you see is painted, powdercoated, or is stainless is a problem? :-hair