Check Your U-Bolts

Big words, I like it, probably should've said " I haven't got the patients"...

 

The 1st-generation did not use the same hardware. It is similarly sized, but not the exact same. The 2015 and 2016 are the exact same.

Jeff

 

Haha, oh really ?? How'd I get 2nd gen Ubolts on my 1st gen ?

I really don't care what you've read or what part# corresponds with what, respectfully , you're wrong...

 

Why are we checking u-bolts? Is there an issue this is supposed to fix?

 

Now the clamps/brackets that Ubolts go thru are different, but the Ubolts/nuts are virtually the same..

I've put 2nd gen Ubolts on 1st gens & vice/versa

 

2nd gen Ubolts on 1st gen...

 

But I'm done , ya'll go with what you believe to be correct, I've spent too much time in the 3rd gen sec. trying to educate, trying to help, not typing to see my shit in print, just sharing my real world experience working on Tacomas ...

 

Whatever you torque them to - how about adding some blue loctite...

 

Yep, good idea Ding,you can lead them to water but you can't make them drink...

 

Geez guys, just asking questions to understand and be informed. Who takes anything they read on the internet at face value without challenging it? I've been working in a tech support business for over 25 years. When we fix something, we want to understand why it requires fixing to start with and correct it there. With 10's of thousands of Tacoma's on the road with supposedly bad u-bolt torques coming from the factory, and no major failures/recalls related to this, I'd suspect that Toyota set those specs for a reason. Before I write off their logic, it makes sense to try and understand it first. With the 2016 spec now up'd to 52 ft-lbs, it appears to be a conscious decision.

 

I wasn't even arguing with you. My point was that even though they are the same size and (obviously) fit and work, they may not necessarily be the exact same grade hardware. It's possible the 1st gen had better hardware than the 2nd gen (and vice versa), while on the newer ones the parts are literally identical from the same factory and yet used different torque specifications.

In any case, your information is not falling on deaf ears, the more accurate information the better. I've seen a lot of misinformation in Toyota truck forums (forums in general, really), and so do my best to provide the most accurate information possible. There are many reasons for a different part number and they may very well be identical just made at a different factory or from a different supplier. (Or 1mm longer or shorter or some other trivial thing)



Jeff

 

Toyota logic you say?
No major recalls you say?

You're right, go do your own research.

 

A while back I showed the Tacoma U-Bolt to my Machinist friend, and he stated that the 37 ft# was a believable value because the U-Bolt is a fine-pitched thread. He said with a fine-pitched thread that there is more total thread surface area that makes contact between the U-Bolt and nut, which would be the equivalent of more torque needed for a coarser thread. TIFWIW.

 

Finer thread can be torqued to a higher value.

Japanese automakers love fine thread.

Jeff

 

Per boltscience's website:

What are the benefits of fine threaded fasteners over coarse threaded fasteners?

The potential benefits of fine threads are:

1. Size for size a fine thread is stronger than a coarse thread . This is both in tension (because of the larger stress area) and shear (because of their larger minor diameter).

2. Fine threads have also less tendency to loosen since the thread incline is smaller and hence so is the off torque.

3. Because of the smaller pitch they allow finer adjustments in applications that need such a feature.

4. Fine threads can be more easily tapped into hard materials and thin walled tubes.

5. Fine threads require less torque to develop equivalent bolt preloads.

On the negative side:

1. Fine threads are more susceptible to galling than coarse threads.

2. They need longer thread engagements and are more prone to damage and thread fouling.

3. They are also less suitable for high speed assembly since they are more likely to seize when being tightened.

Normally a coarse thread is specified unless there is an over-riding reason to specify a fine thread, certainly for metric fasteners, fine threads are more difficult to obtain.

 

Yup, they require less torque, but can also take a higher torque value as well.

Jeff

 

What is the T-rating?

 

What do you mean?

Jeff

 

Toyota's way of designating bolt strength.

 

I would not trust a harbor freight torque wrench.