Spring Clamp Warranty Risk

Will adding leaf spring clamps to a stock 3rd gen 2WD pose a risk to the driveline warranty for any reason ?

 

Leaf springs clamp? The u bolts?

can you post a picture or a link what you talking about?

 

Superior 13-1401A Leaf Spring Clamp Kit, manufacturer part # 13-1401A, Amazon ASIN # B001DKSM7Y.

Front and back clamps on each leaf pack, covering all 4 leaves.

 

Asking for legal advice on an Internet forum is never good.

I’m not a lawyer, nor am I qualified to give legal advice.
But I’d venture to say, IF the clamps ARE THE CAUSE of what ever issue. Then yes, it will affect warranty.
You kind of need to “read between the lines”, and be prepared for battle if an issue occurs. Every dealership is different.

 

Don't worry, I'm not a lawyer either and I don't expect perfect answers from a forum. I'm just curious about opinions related to what this kind of modification 'might' mean to the stresses and strains on the driveline, say over a year or two. I'm thinking virtually negligible, but I know there is vastly more experience in this forum than in my location.

 

Why do you want to add these? Leaf springs move around a lot. Binding them up could cause problems.

 

The problem being solved is a vibrating shudder that kicks in while holding the brakes on, under somewhat more than average pedal pressure as the truck slows below about 20 mph. Using all 4 clamps virtually eliminates it, and using just the front 2 wipes out most of it. What kind of problems are caused by binding other than some extra stiffness over bumps?

 

Most likely it should be fine. But….if something happens to the diff or rear suspension. They might blame it on these. If it’s something like the engine or electrical….don’t think it would matter.

 

Understood. Thanks. The more I think about it the more I realize a very tiny effect could radiate all over the place. I expect any driveline angle effects should fall within the normal range that occurs from varying loads in the bed though.

 

Since your getting axle wrap check the torque on the u bolts (73 ft lbs for oem) or consider a new leaf pack. Just curious... do you have blocks in the back?

 

The truck is an unmodified stock 2021 SR5 2WD with low mileage. Thanks for the U-bolt torque info. I will check that. If it's OK, I will just drive it without the clamps. I like to take it easy on the brakes anyway. With this being the source, I don't know for sure, but am assuming there's not likely to cause extra wear and tear on parts in the driveline that would show up soon after the warranty expires. Some years forward, new leaf springs could become doable.

 

If it is axle wrap the stock springs are the cause. Like you said just come up to stops gently.

 

At what positions on the leaf pack are you adding these? Are they causing any visible difference in the leaf separation?

 

The 4 clamps were temporarily put near the ends of the bottom (4th) leaves (the ones with the gaps). They eliminated almost all the separation between the 3rd and 4th leaves. Putting on 2 per side, front and back, erased virtually all the vibration. Even just using a single clamp on each side in front of the axle did a pretty good job. Now that I know what's going on, the clamps are off. From what I can tell, the nuts on the u-bolts that bind the springs to the axle are currently supposed to be torqued to 37 foot pounds, not 73. Six out of eight on my truck matched that number from the factory. The other 2 front nuts on the starboard passenger side were a couple of turns looser than that. Getting them all set to 37 didn't make much difference in the vibration. The 37 spec puzzles me because it seems the correct number 5 or 6 years ago was 52. If that's true, I have to ask what's been going on at Toyota?

 

37 ft/lbs for the the u-bolts does not sound right, but it's been 2 years since I upgraded my leaf springs. Check the service manual. There are links to a copy of it on this forum.

EDIT: found it for you: https://www.ttguide.net/rear_leaf_spring-1411.html 52 ft/lbs

 

Be advised your link shows the PREVIOUS 52 ft/lbs. My 2021 came from the factory with 37 (or less), and 37 is the current official specification. I just do NOT understand why. Did the only changes occur between the ears of the engineers?

 

Where are you getting the official spec? It seems odd they would change it. Nothing substantial has changed since 2016.

For whatever it’s worth, my 2020 is torqued to 52 with no issues, but I have OME Dakars.

 

What's the diameter of your oem u bolts? My aftermarket 9/16 bolts recommend 90 ft lbs.
https://www.suspensionspecialists.com/techinfo/Ubolt_Information.pdf

 

I think this link: https://techinfo.snapon.com/TIS/Register.aspx
might work, but your local dealership service department can just tell you.

Besides, if 52 was still the number I'd expect it to be pretty close to that from the factory.

 

37 is a somewhat well known misprint in the service manual the real torque is 73 foot pounds not 37.