Scary? Short U Bolts

I had a feeling you BOTH would be in here

 

No, that is not what that means. They don’t loosen, the bolt stretches. That is normal.

Why did you put loctite on something that you will Re torque? Kind of defeats some purposes. Why would you think that a bolt you put loctite on became loose?

 

Yea cross bolt pattern. What magic hat did you pull 80lbs from? Is that for your 2005 or @D Soulman (and mine) 3rd gen OR? Please don’t quote exact torque specs unless your absolutely sure that’s what it is and please give a reference.

 

I’m referencing the 2nd gen FSM which states 37ft lb but is widely accepted that that is a typo/incorrect. So, I and many others torque to 80lbs. I suggested that to OP since 2nd and 3rd gens are similar in many ways.

 

No that’s not normal. When a bolt is torqued to spec, the bolt stretches as it gets tightened. It doesn’t just continue to stretch as he goes and drives around. Please don’t respond unless you’re absolutely sure that’s what it is and please give a reference.

 

The FSM is incorrect at 37 ft-lbs. It should be 73 ft-lbs. for a 2nd gen. Tacoma.
Those are for OEM bolts, btw.

 

What I have found for 3rd gen OEM U bolts.

https://www.tacomaworld.com/threads/2016-tacoma-u-bolt-torque-spec-anyone-know-for-sure.432346/

 

And it should be 1 bolt diameter of thread engagement.

10mm bolt = 10mm of thread engagement

 

You don't understand what is going on, which is why you felt it was ok to drive around with bolts that were too short.

Bolts stretch. As a matter of fact, it's the best way to determine if a bolted joint is tight. We use torque only because measuring bolt stretch isn't always practical.

When you have lack of thread engagement, the bolt has that stress applied to a smaller section of the bolt. It's alot like just using a smaller diameter bolt.

You might get by, but those bolts are designed to withstand abuse from bumps in the road and never giving you problems. Hitting a pothole or a 2x4 in the road might provide the spike in stress that you need to lose the rear end.

 

Because I didn't plan to "re-torque", I planned to check the torque and thought that if it was done correctly they wouldn't move. One side did not move. And I don't know why properly torqued bolt with loctite became loose- kind of why I posted up again..

 

Did you tighten in a cross cross pattern with an even amount of threads showing on all 4? My guess is no which is what caused it to shift around.

 

And to clarify, you want to gradually tighten each bolt, constantly shifting around to keep everything equal.

 

Well, I tightened them so that there was more thread on the front ones because the shim is thin in the front and thicker in the rear, but made both sides of the front and both sides of the rear "even"- via eyeball test.

 

Another thing that makes me wonder is that the new ones are not factory (purchased from Toytec). How do I know if they have the same torque value as factory? Or am I just getting off into the weeds and don't need to worry about that?

 

I have non factory u bolts. Gradually increase torque so it’s all even to 80 fat lbs. if you do that, you shouldn’t have issues.

 

Wait, what exactly is a fat lb? I keed, I keed...

 

I appreciate the advice. I think I will finish reading the long thread before torquing them again.

 

Diameter and material determine what the torque should be. Toytec should be able to tell you what the torque of their bolts are.

I would guess that it's the same as OEM, but that's a guess.

 

Thanks, I may call or email them to make sure I get this right.

 

That is a g̶o̶o̶d̶ great idea.