Ubolts under torqued

*gremlin

 

Oh and your avatar looks like Nicholas Cage playing David Grahl.

 

IIRC about Toyota docs...

it cannot be a typo of 37 or 73, because Toyota engineering calculates torque in newton meters...foot lbs is a translation. There would need to be dual concurrent mistakes for it to be a typo. 50.7 nm vs 98.97nm and 37 vs 73 ftlbs. The FSM shows both 37ftlbs and 50NM, and both are equal to 37ft. so, that is a lot of characters to excuse as a 'typo'. I don't buy it. intentional...

this 37ftlbs is absolutely intentional, or the supposed typo (item 3 above) is on the engineering docs not the service docs.


Now where in the HELL is Lagunito when we need his advice on torque ????

 

Now 127 makes a great point...so the real question, if it is not an error then is 37 ft/lbs the correct torque?

 

checked my on 2012 and couldn't move them but maybe a hair full force on a 3/8 wrench, don't have a torque wrench to see when it would give, but tighter than I can move has to move more than 37lbs

 

Typically, torque is a function of the fastener size and whether there is lube involved or not. Dry torque is higher than lubed torque.

Torque the U-bolts to 75-80 and forget about them.

 

HOLY CRAP !

Ok, I have a 2013 turd or, and also have the 15-25 tsb vibe

I was planning on getting the tsb done

NO MORE !

torqued 50, they all were far looser
torqued 80

NO MORE VIBE ISSUES* !

*OK...so I still admit there is barely a whisper of a vibe but
I really have to hammer to feel it. Drive like a dick level. I can now pretty much
blast around all sporty-driving-like and NO MORE VIBE 15-25 (or any speed).

learned:

a) Toyota spec must be an error, I mean damn !

b) those who get the tsb done and then say 'only made it worse'
all I can figure is they put torque to 37, which is freaking wrong in my book

 

good to hear erik, i know its not 37lbs.....

 

Honestly I figured you all must have bunk tacos . I was figuring my 2013 was solid, no need to check.

So I did just now before heading out. Many nuts were less than 40ftlbs. I set em all to 70. Plus or minus a little with variances.

 

It certainly doesn't hurt to tighten them to 73 -- I tightened them on my 2012 within 2 weeks of owning it and took some pretty rough Colorado trails without losing the axle.

37 doesn't seem right, but most owners have no clue and there is no recall, so I have to assume that 37 is enough to work.

 

Ours are 1/2"... not sure about the material grade.
http://www.autoandtrucksprings.com/pages/U-Bolt_Torque.html

 

Well, considering that 1st gens are spec'd for 90ftlbs, theres nothing magical or special about 2nd gen Ubolts (they're the same as 1st gens., swapped out many times)

You guys need a refresher....

http://www.youtube.com/watch?feature=player_embedded&v=X8Sg8dCtXnI#t=3s


NO WAY IN HELL IS THIS TIGHT ENOUGH !!

Especially to hold a moving,flexing, 400lb + axle assembly (not counting tires/wheels)

 

all I can imagine is 37 softens the ride a bit ? to satisfy those who want
a truck to drive more like a car. (most of the market)

I swear the arse is a bit firmer at 80...


anyhow, the annoying vibe is fixed

 

I pulled one u-bolt off yesterday to get longer ones made for my new springs and could not believe how easy it came off.

 

I pray you're kidding....

& glad you tightened things up...

 

This morning my service writer confirmed that the torque spec for the u-bolts is 37 ft-lbf.

He pulled up an online version of the FSM for my 2013 Tacoma and printed out the 4-page section on rear leaf spring installation, where the torque spec is listed in two different places.

Intuitively, 37 ft-lbf is too light for the u-bolts, and 90 (+/-) ft-lbf seems reasonable and ties with the spec for earlier models. Then again, I find it hard to believe that a typo of this magnitude could survive for years without being corrected. Strange.

 

I find it harder to believe that someones axle hasn't went bouncing down the road somewhere....

& this isn't directed at you but I don't give 2 shits about what Toyota has to say on this about there product, anyone who thinks that 37 ftlbs is enough, is a fool in my book & no way would I let them have a wrench in their hands on anything I own or was working on...

 

Yeah, I agree with you on both points. Then again, it makes zero sense that this is a mistake that hasn't been corrected. So, the question is "WHY"? It doesn't really matter on a practical level, but it just makes me wonder what's going on.

 

I agree with them seeming too low at 37 ft.lbs and that Toyota had this in their fsm for sometime without the need/desire to change it. However, I have mine torqued down around 85-90 ft.lbs, but I've added an AAL and went with that info for install.

Any info on what other manufactures have for their u bolt torque specs?

 

umm....