Strange "grinding" noise after add a leaf install

Installed a 1-2 inch "add a leaf" today and now when I decelerate a hear a grinding type noise. Seems to only happen above 55 mph. Also the noise happens even in neutral but not a loud as when it's in gear.

Any ideas?

 

Since it started with the AAL install, I would check those out first.
Could be loose u-bolt nuts. Torque them to factory specs.

 

85ftlbs for u bolt torque. Then after about 100 miles of driving, retorque them. Try greasing your U joints, grinding may go away. Also check for any play in your U joints and shaft bearings. Grinding could be a bad bearing as well.

 

Thanks for the input guys but I ended up taking the AAL's out today and all is back to normal. I even took the truck to the local 4 wheel shop and they said they never heard of anything like that with just an AAL. Their best guess was the same as mine - the standard cab has a single drive shaft and it might be the angle of the shaft that was causing the problem. They recommended shims. They also said some of the major kit makers don't even have a kit for the 2012s yet so maybe they are having the same issues with AALs on the kits.

Either way I yanked out the AAL and plan on trying angled blocks to see what happens.

 

Don't go the blocks route bro', re install your leafs & shim it right there on the spring perch on axle, your diff/pinion angle needs to go up a tad.. this is pretty typical for a one piece shaft, the blocks may be simpler but I promise , you'll hate the ride...

 

i say re-install with degree shims..
i have a couple you can have.

 

Can I come over your place and do it?

I don't think my U bolts are long enough though

 

well i don't see why not

i got some u-bolts too

 

There ya go Man !! Niiice !!

Way to stand up & help a member dude ...!!

 

Yea BMOC is super cool, second time he has offered to help me out!

 

I don't agree. If your AAL is a single leaf, don't use it.
Shitty ride, and increases the likely-hood of breaking one
of the other leaves.

Progressive 3-pack AAL is the way to go, if you're going to use AAL .

If you go with shims, be sure they are steel, no aluminum.

 

Had a clanking noise just today and also had a Deaver AAL install several months ago. Sure enough in was my driver side U-Bolt. I took advantage and also greased the AAL along with torquing the U-Bolts to spec.

Noise was immediately gone