Nnbs Removing Just The Rear Blocks For Semi-leveling

icetraxx · February 2, 2010

I measured the front and the rear spacing of the tires to fenders and there is exactly a 2" difference. If I remove just the blocks out of the rear it will give me approx a 1" rake. Is there any down fall to doing this. I thought about installing a 1.5 lift kit for the front but I am then looking at the expense of an alignment.

herkdriver007 · February 3, 2010

definitely an option if you want to lower the rear instead of raise to front to level the truck. Also FWIW the OEM block is 1.25".

team3-8 · February 3, 2010

don't reuse U-bolts.

kalashluvr · May 30, 2010

don't reuse U-bolts.

I want to do the same thing here...are you saying don't reuse the U-bolts that are on the truck right now if I remove the block? If I don't need to reuse the u-bolts, do you simply replace the ones on the truck right now with an aftermarket bolt or the identical factory bolt....THANKS IN ADVANCE.

team3-8 · May 30, 2010

I was told not to reuse u-bolts because of all the torque used to tighten them. Shorter ones can be had at any parts store.

Zembonez · May 30, 2010

I've heard a lot of people say "do not reuse the Ubolts" but the OEM Ubolts are superior to the auto part store chinese cheapos. I would have no problem reusing them if they have enough thread to be tightened properly (not sure if they are or not). Just bring them up to tight and then torque them. I've seen shops reuse them many times when replacing leaf springs... I can't see any difference.

Matt_ · May 30, 2010

I've heard a lot of people say "do not reuse the Ubolts" but the OEM Ubolts are superior to the auto part store chinese cheapos. I would have no problem reusing them if they have enough thread to be tightened properly (not sure if they are or not). Just bring them up to tight and then torque them. I've seen shops reuse them many times when replacing leaf springs... I can't see any difference.

You're not supposed to re-use U-bolts because they're torqued to around 90% yield strength of the material. It has nothing to do with quality, it has to do with their design.

Bolts do a lot more than just "hold" stuff together by "squeezing"... there's a lot of other design aspects involved. Some bolts even act as springs... although the deflection is not visible with the human eye.

A lot of people don't know this and improperly re-use U-bolts. Most good mechanics know that they're not supposed to reuse them but dont know exactly why; so they say the same thing you did, "i dont see what the difference is", and put them back on.

Matt_ · May 30, 2010

Since no one believes things they read on forums, here's a nice link that provides info about u-bolts: http://www.lhrods.com/ubolttorque.htm

And another:

http://www.eatonsprings.com/ubolttorques.htm

Zembonez · May 30, 2010

I've heard a lot of people say "do not reuse the Ubolts" but the OEM Ubolts are superior to the auto part store chinese cheapos. I would have no problem reusing them if they have enough thread to be tightened properly (not sure if they are or not). Just bring them up to tight and then torque them. I've seen shops reuse them many times when replacing leaf springs... I can't see any difference.

You're not supposed to re-use U-bolts because they're torqued to around 90% yield strength of the material. It has nothing to do with quality, it has to do with their design.

Bolts do a lot more than just "hold" stuff together by "squeezing"... there's a lot of other design aspects involved. Some bolts even act as springs... although the deflection is not visible with the human eye.

A lot of people don't know this and improperly re-use U-bolts. Most good mechanics know that they're not supposed to reuse them but dont know exactly why; so they say the same thing you did, "i dont see what the difference is", and put them back on.

Well... I understand what you are saying and while that sounds good, I'd have to see some specs to believe that they are actually that closely designed and built to such strict tolerances. I've never seen or heard of one failing and I know some pretty high end shops that reuse them regularly.

I understand what you are saying from an engineering standpoint.

Matt_ · May 30, 2010

Well... I understand what you are saying and while that sounds good, I'd have to see some specs to believe that they are actually that closely designed and built to such strict tolerances. I've never seen or heard of one failing and I know some pretty high end shops that reuse them regularly.

I understand what you are saying from an engineering standpoint.

See the links in my other post.

It's not that they're built to some super tight tolerances. Their torque value is such that it makes the material deform to acquire proper clamping force.

Just because you haven't heard of one failing doesn't mean that you should ignore proper installation. $.02

Edit: I also know a lot of high end shops and ASE Master techs who dont use a torque stick or torque wrench when putting wheels back on. Doesn't make it right...

Zembonez · May 30, 2010

Well... I understand what you are saying and while that sounds good, I'd have to see some specs to believe that they are actually that closely designed and built to such strict tolerances. I've never seen or heard of one failing and I know some pretty high end shops that reuse them regularly.

I understand what you are saying from an engineering standpoint.

See the links in my other post.

It's not that they're built to some super tight tolerances. Their torque value is such that it makes the material deform to acquire proper clamping force.

Just because you haven't heard of one failing doesn't mean that you should ignore proper installation. $.02

Edit: I also know a lot of high end shops and ASE Master techs who dont use a torque stick or torque wrench when putting wheels back on. Doesn't make it right...

PROPER INSTALLATION!

A lot of this is opinion and covering of ass. In this day of frivolous lawsuit after frivolous lawsuit, most companies "recommend" replacing anything you touch to get to the part you are replacing all in the name of "safety". Even people selling these things include statements like "should be replaced" "recommended replacement" etc in their instructions. I guess we can agree to disagree a bit here. I'd reuse mine in a heartbeat if I were just removing the block.

Matt_ · May 30, 2010

Don't know how else to explain it Jim... it's not CYA, it's inherent to design.

It's just like how you're not supposed to re-use bolts with thread-lock... they're 1 time use (unless its a type of thread-lock that you can reapply).

I'm not stating opinion.. im stating design fact.

You don't hear them failing all the time because engineers have to account for expected negligence and therefore we design "safety factors" into every system (this also accounts for material inconsistencies as well as other influences such as degradation with time/environment).