2014+ Lowering / Drop Kits

CL8N · August 10, 2014

I remember reading someone recommended replacing the u-bolt. Don't know if it was this thread or why they recommended it.

stevev · August 10, 2014

I remember reading someone recommended replacing the u-bolt. Don't know if it was this thread or why they recommended it.

thanks, from what I gather, you may run out of threads to reattach the nuts on the U-bolt after the block is removed. So I guess you just buy the u-bolts from a 4x2 model that doesn't have the rear block? But I thought I saw someone on here that the person reused their 4x4 u-bolts.

CL8N · August 10, 2014

I thought it had to do with the travel of the newly exposed threads, maybe they can be cut. I can't recall though. Just speculating.

CL8N · August 10, 2014

It's interesting you would say that. I know there's a lot of opinions on this and other forums. Many saying to use new and just as many saying they didn't and nothing bad happened so I did a search looking for what I would consider a reliable source and came up with this:

HOWEVER, read the following transcript:

SO, since removing the block moves the nut 1" further up the threads you are using virgin threads and should be able to apply the proper torque and have that torque retained. Of course, if you decide to go back to using the block then you need new bolts because you will be back into the area of the threads that were deformed by the original installation. No new bolts needed for this operation, only if I go back to using the blocks.

The re-torque after two weeks perplexes me. Are there guys running around dealer lots re torquing u-bolts? How is it the factory can install them and they are good for years but I need to re-torque?

Perhaps this is due to the explanation above where old parts wear different than new, which seems a bit far fetched to me AND I doubt the movement on the bolt would be more than a few hundreds so you aren't going to get into any significant "new" threads as mentioned above. Since the Truck is all of 2 weeks old I don't think the old parts vs. new is an issue but I will check just to see if there's any truth to the legend.

Has anyone who's played around with u-bolts ever seen them loosen up after a few hundred miles or is this more urban legend than sound engineering?

Here's the original post talking about the U-bolt

Chubs · August 22, 2014

Hey everyone, new at the forum..Just got a 2014 Sierra a week ago and installed my Rough Country 2/4 Lowering kit on the weekend, took about 4 hours with 2 ppl. Love the look but there was some vibration. I got 6* pinion shim installed today and all vibrations are gone..

whodatfan · August 22, 2014

Hey everyone, new at the forum..Just got a 2014 Sierra a week ago and installed my Rough Country 2/4 Lowering kit on the weekend, took about 4 hours with 2 ppl. Love the look but there was some vibration. I got 6* pinion shim installed today and all vibrations are gone..

How did you know how many degrees you needed to shim? Also, what is the part # for the shim kit? I have 2" shackles with block removed for a 3" rear drop on a 2014 GMC double cab. Edited August 22, 2014 by whodatfan

Chubs · August 23, 2014

Well since I'm kind of new at this, I did some research on how to measure the angles, and that's what I did..then I read about what other people have done for this kit, and I decided that a 6* would be a good place to start. I measured the angles again once I put the shim in to make sure I got it where I need to be, and right now I'm within 1/2*. I got the shim kit from Summit racing, just search for a 6 degree pinion shim.

whodatfan · August 29, 2014

I already have 2" drop shackles installed, so how do I determine what the factory pinion angle was? Also, how to figure out how much 3" of drop will change the pinion angle? Does the truck need to have the 3" drop in place first to then measure the difference?

Chubs · August 30, 2014

It doesn't matter what the factory pinion angle was, it's what you need to be at after the modification. You have to match it to your transmission angle.

I don't know how to figure that out, but if you drop it further just take a measurement and you will find out then.

whodatfan · August 30, 2014

With a little Photoshop magic, here's my truck sitting about how I'd like it. Maybe it is 6/8? Don't know. Why do y'all think?

Luster · August 30, 2014

With a little Photoshop magic, here's my truck sitting about how I'd like it. Maybe it is 6/8? Don't know. Why do y'all think?

Yeah, that looks like a 6/8. It's 2WD right? I don't think you'll have any problems in the rear with a flip kit and drop shackles... the front will be a challenge. Make sure you go under-size on tires and a pretty high positive offset for no rub. Possibly narrower/smaller tires in front than rear.

Edited August 30, 2014 by Luster

Tkramer5 · August 30, 2014

Fellas I need some help. I've looked all over this site and can't find an answer. Just put maxtrac shackles on my 14 sierra AT. Took about an hour. Dropped hitch and gently persuaded bed seams like everybody does. Installed new shackles. Dropped it off the lift and tightened like Maxtrac says to do. Here's the issue. RR is 1" higher than the LR. So rear end is actually crooked. I had maybe .150 of the "Chevy lean" before I started. I've checked and double checked everything. Loosened and re torqued everything. Check shackles to make sure they were the same also. Clearly I did somethin wrong. Need some help figurin out what!! Sorry if I'm missing a post about this somewhere else. Thanks for the help guys.