Ruined day!!!

[DaytonaBill]

Well, I got everything I could think of, from drill bits, torch, 18 pcs of 12/12/1.5 inch wood pads for two bottle jacks, two 18" jack stands, poly bushings, ball joint press, sawzall blades and coveralls...

I had planned to change out the front end bushings for my '92 4x4 f350 crew cab...

So, this morning, I decide to go over in my mind the motions I would be going through during the job and when it came time to torque down the u-bolts (in my mind's eye), I realized that I didn't have the slightest clue as to what the torque values would be...

So, since 9 this morning (it's 1:08 now ), I been scouring the internet and this forum... I did find that the u-bolts are 9/16", but what grade are they and what are the torque values for them? Dry or wet?

I guess I'll try again next weekend...

Thanks everybody...

 

[chris142]

nobody torque that stuff. run it down till its tight.

 

[79jasper]

150 ft/lb.


Sent from my iPhone using Tapatalk

 

[LCAM-01XA]

nobody torque that stuff. run it down till its tight.

Speak for yourself. Some of us actually do give a darn about materials tensile strength and yield and all that. Also there's a good chance your "tight" and my "tight" and someone else's "tight" are gonna be quite different. It's a front axle, don't fawk around with it.

DaytonaBill, read this, the entire page, including why you should not reuse U-bolts but drop new ones in instead.
http://www.stengelbros.net/U-Bolts_c_23.html

 

[ToughOldFord]

Unless rusted or damaged I always reuse u bolts, they are not torque to yield and yesterdays HD bolts and nuts are much stronger then the crap made today. I have never had a reused axle bolt fail and my rigs play and work hard.

Edit: And you'd expect to find from a widget company reasons why you shouldn't reuse your old widget, you must buy new and from them.

 

[LCAM-01XA]

It has nothing to do with torque to yield, it's cause of how the threads are made on the bolts. If the factory u-bolts threads are cut with a die then I suppose you can reuse them like any other non-TTY bolt. The Dayton bolts (what Stengel Bros and many others sell) have their threads rolled, and according to them (Dayton) the threads get slightly deformed as the nuts get torqued on.

Do whatever you chose to. My personal policy is NOT to reuse a fastener if it required heat application for initial removal. And I'm yet to run into a U-bolt that didn't need some heat for the nuts to let loose, even on desert trucks. Well on the desert trucks I could spend an hour per side trying to work the nuts loose with penetrating oil and all that, but I got no patience for that. How much is your sanity worth? Mine is worth to me more than the $60 I pay for brand new Grade-8 5/8" bolts (giving rear axle as example here simply cause its bolts are more expensive). My current bolts are like a year old and still look like brand new, yet they're getting thrown out in a few months when truck gets 4" lift. Not cause I can't reuse them, but cause when it comes to a vital suspension component I'm a bit more inclined to take the word of the people who made it over that of some random person on the internet (no offense). You are free to exercise different practice, whatever floats your boat. New U-bolts float mine quite well

 

[ToughOldFord]

Wait a second here, you're throwing in an extra factor that wasn't discussed before. If you have to burn off the nut there may be something said for the bolt losing some of its temper and should be replaced. I don't know personally, I'm not a steelworker and I've never had to use heat on a axle bolt before. Just WD40 or PB and a 1/2 drive wrench.

I would hope that some of us that try to help others while open to learning new things themselves would get a little more credit than just being "some guy on the internet". You can tell over time by a person's messages if they have actual knowledge and hands on experience with machinery use and repair.

 

[LCAM-01XA]

Oh but just using the ratchet and penetrating oil isn't all that great either tho, as it twists the bolt shank every time you pull on the handle. So the u-bolts already got some light twisty action while they were being torqued down (not much cause of oiling and fresh threads), now you're twisting them the other way, and then you'll be twisting them once again upon reinstall, likely without even chasing the threads first (cause really how many of us have fine-thread 9/16" and 5/8" taps and dies?). This on a bolt that's been fatiguing for 20-some years now. Don't sound like too good of a plan to me.

And when it comes to stuff like that, every one of us here is "some random guy on the internet", myself included. Why, well cause if I follow your advice and it ends up blowing up in my face for whatever reason, I really can't sue you for the damages since it was ultimately my decision to do the work that way and it was my fault for not considering other sources of information before making said decision. On the other hand if I install a brand new part and do it properly according to the manufacturer's procedure, if it fails and my truck gets wrecked as a result, I could go after the manufacturer cause of their defective part. Oversimplified scenario of course, but you get the idea. So yeah, unless I purchased a product you made and I'm asking you for tech support on it, yes you are "some random guy on the internet" regardless of what ridiculously high experience you may have in the area discussed. And so am I to someone else. And so are they to yet some other person... Make sense?

But this is getting way offtopic already - bottom line is for a peace of mind I recommend using new U-bolts every time springs are messed with, whether DaytonaBill or someone else in his situation follows said advice is entirely up to them.

 

[Agnem]

I replaced my pivot bushings on the Moose Truck without messing with the springs. I just used jacks and the weight of the truck to push the pivot ends down far enough that I could press them out. Then installed, jacked up and aligned without an issue.

 

[DaytonaBill]

Well, this certainly has been an educational (to me) thread. I never knew there was such an animal as a rolled thread bolt or stud...

I want to thank everyone who responded to my query, Thank you very much!

While I do understand the mechanics of what a rolled thread presents, there is a part of me that wants to disregard the fact that the combination of rolled thread and deep nut guarantees that the nut will never back out... Due to the distorted threads...

Basically this is the way I understand it... The rolled threads, in conjunction with the deep nuts, generally makes it a one time use... Because the threads are designed to distort as a means of locking down the nuts... Am I seeing this correctly?

I think I am...

So, I'm going to reevaluate my plan and pattern it using Agnem's method...

I'm going to jack the truck up, lower the driver's side and R&R the back eyelet and then do the front eyelet and shackle at the same time... And repeat for the other side...

Without touching the U-bolts...

Thanks everybody, I was able to prepare a better plan using your input. I will succeed because I'm standing on your shoulders...

 

[ammocan]

I did u bolts 2 days ago and learned a lot. I did one side and the nuts were distorted to the point where I had to use a breaker bar to get them all the way off. I intended to re-use the u-bolts but when I put them back on I realized that I could not get an accurate reading on the ft-lbs because the nut took a lot of torque just to get it threaded. I decided to go get new u-bolts and I went to an industrial truck parts place where they made me custom length u-bolts for $16 a piece. I spoke with the guy who made my u-bolts and he explained to me that the torque specification is engineered to pull the threads slightly to not allow the nut to work loose over a long period of time. This is especially important when dealing with industrial trucks. He also explained that the fact u-bolt threads are pulled and distorted when installed this requires new u bolts each time they are removed. On light duty trucks this idea can be argued and you can ***** your own risk but I chose not to especially when they are not expensive.
If your having trouble with finding torque specs and questions on materials do what I did a find an industrial truck parts supplier and ask them the questions. The problem is the torque values are going to be different based on the product you buy. The u-bolts I purchased were a higher grade material than the stock ones I scrapped and the threads were different so the torque values were different than oem u-bolts.