Rear Axle U-bolt Torque

[oneandzero]

anybody else notice the glitch this forum has of the reply window doesn't always close when you hit post. So you hit post again and again and again.

[SouthernSilveradoGuy85]

anybody else notice the glitch this forum has of the reply window doesn't always close when you hit post. So you hit post again and again and again.

 

Refer to your sig lol.

 

I just click it the one time and then refresh if it does that. Never had a problem with it not posting when I did that.

[TxTruckMan]

This glitch happens when somebody adds a post to the page before you click POST.

[newdude]

Again... 59ft lbs in a criss-cross pattern. Then 130 degrees in the same pattern.

 

For anyone visiting this thread, this is the correct spec for 2014+up 1500 trucks.

[FL335i]

Thank you 15HDriver. I will re-torque and TTY 130* mine this weekend. I have to ask.... are they all this loose from the factory? How are they not torqued in assembly? Are the bolts stretching?

[Ron.s]

To go by the book you should replace U Bolts and nuts. The idea behind proper torque is that it stretches the threads so that as you loosen them it's a little like they were cross threaded. Once stretched they should be replaced. The other alternative if you aren't going to replace is to double nut where the 2nd nut has fresh threads.

Obviously they weren't torqued properly from the factory or else the assembly has worn in a little and that resulted in a slightly looser fit. But if they weren't set at proper torque then the threads weren't stretched so.......

Most dealers would replace the U bolts and nuts so take it back and save the expense?

[FL335i]

^I've re-used U-bolts in the past on my trucks. Does GM specifically state to replace the U-bolts whenever removed?

[muddkatt]

^I've re-used U-bolts in the past on my trucks. Does GM specifically state to replace the U-bolts whenever removed?

 

Its not just GM that recommends changing the bolts, its basically an industry standard. Here is a link to a forum where the OP links to several u bolt manufactures and they all basically say to change them if they are removed.

http://www.eng-tips.com/viewthread.cfm?qid=256363

Now just to torque them down to specs, I don't see a need to change them.

[FL335i]

^ Agreed. So when I swap out my rear leafs from Z85's to NHT Max tow leafs I should (and will) buy new GM U-bolt and nuts to go with them. Re-use the nuts.

[SierraMyst]

Again... 59ft lbs in a criss-cross pattern. Then 130 degrees in the same pattern.

 

So when I retourqued mine a month back I did the 59 plus 130 degrees.

 

Since I did not have an exact way to measure 130 degrees, I torqued the bolts to 59, then did a 90 degrees pass, and then another 45 degree pass.

 

That put me at 135 degrees give or take, but it was easier to measure in increments of 45 degrees.

 

So today I took the torque wrench to 80 ft.lbs. and checked each bolt.

 

All of them clicked immediately.

 

So apparently the 59 ft.lbs. Plus 130 degrees is over 80 ft.lbs.

[FL335i]

^Very good info SierraMyst.

[Rebel619]

Hello, I am fairly new to the website and have been doing a lot of good reading on this site. Now I have a 2015 silverado 1500 ltz z71 4x4 and the bolts on my u-bolts are 21mm, I noticed everyone else claiming they had either 14mm or 16mm bolts for they're u-bolts. I am missing something here? Seems like thats too big of a difference from everyone else's u-bolts...

[Rebel619]

Hello, I am fairly new to the website and have been doing a lot of good reading on this site. Now I have a 2015 silverado 1500 ltz z71 4x4 and the bolts on my u-bolts are 21mm, I noticed everyone else claiming they had either 14mm or 16mm bolts for they're u-bolts. I am missing something here? Seems like thats too big of a difference from everyone else's u-bolts...

[hirdlej]

I'm on my 4th new rear differential in my truck (3rd full assembly). Each time the dealership has reused the U-bolts. My U-bolts have been installed and torqued 3 times. When I asked the dealership they said they were told by GM to reuse the bolts. The u-joint straps and bolts are TTY though and have been replaced each time.

[allenwhite88]

Can I use a regular ratchet? I don't have an air wrench.. if so, Tighten them 1 turn?