Leaf Spring U-Bolts

Just hit 5k miles and had service done. Saw guys on here recommending a u-bolt torque check while I'm at it. I know its 52ft-lb but does anyone know if you should do that unloaded?....as in the rear end jacked up so the springs are unloaded or can you just crawl under there and check them with the torque wrench?

Got a 2wd sport, so any other things to check while I'm at it would be appreciated

 

I honestly dont think it matters a whole lot for u-bolts. When I lifted my truck, I snugged them in the air and then gave them a final torque to spec while the truck was on the ground and after bouncing on the back (since the service manual tells you to do that for the shackle bolts). Be sure to recheck the torque after about 100 miles or so.

 

Thx...I just crawled under the bed and tightened them up. Glad I saw the mentions about them, Torque wrench set at 52ft-lb turned one of them about 3/4 of a turn before it let go and truck has only 5200 on the clock. Definitely a good idea.

 

5300 odo, 5 of 8 were loose by a turn or so before clicking at 52 ft-lb.

 

Just remember if you are in aftermarket suspension you should be taking these to 80+ ft lbs

 

52? That isnt anything. Wasnt there a typo in the FSM regarding the torque on those? My 1st gen is 90 ft lbs. Pretty sure the bolts are the same size across all generations so Id take them to at least 80.

 

2nd gen FSM listed 37 ft lbs; assumed to be 73 ft lbs.
52 ft lbs is what is listed in the 3rd gen FSM.

Torque will vary depending on grade, diameter and thread.

Besides, it's not so much about torque as it is clamping force.
Improved design changes in mating surfaces(ex. u-bolt top and bottom plates) can increase clamping force given the same amount of torque.

That said, when I had the stock u-bolts, I took mine up to 75 ft lbs with no ill effect. This was before the FSM was available.