Slow, periodic grinding or vibration after lift and alignment

Hi all, I just installed a Toytec Boss 2.5 complete lift kit, got it aligned, and now have a mysterious, periodic grinding noise. At 45mph, it cycles like a sine wave about every second, going from no noise to a grinding that isn't real bad but can certainly be heard and felt, back to nothing, then to grinding, etc. The cycling period varies directly with speed. It is a lot slower than tire revolutions and the tires only have about 1000mi and were rechecked so I don't think it is a balancing or uneven wear problem. I only have 32,000mi on the truck, and it was working fine before installing the lift. It has the driveshaft carrier spacer installed, and a differential drop was installed and there was no change. Another interesting aspect is if I put it in 4wd, the noise goes away. The shop that did the alignment tried for an hour to figure it out, with no luck and was not able to pinpoint it. The powertrain warranty will be up soon, and I'm not sure what they will say since there is a lift on it. Anyone experience this before?

 

Drivers side needle bearing, time for clam shell bearing.

 

Check to make sure the backing plate for the front brakes. It could have been slightly bent during lift install. And the rotor is rubbing it as it turns. I have seen this a few times.

 

Use East Coast bushing to replace needle bearing on drivers side. Don't know what that dude two posts above is talking about.

 

All good suggestions, and with that info I found some other applicable threads on how to do it etc, thanks.

 

You had me at slow, periodic grinding

 

You forgot the dB rating on the verticle line of your graph. I find your diagram laking information to make an educated guess. Lmao

 

Are you referring to me? Calling it a clam shell bearing?

 

I wasn't sure what you were referring to either, at first, but a quick search after your first post using your terms came up with this, https://www.tacomaworld.com/threads/needle-bearing-yes-replace-it-ecgs.716338/, so it was really helpful, thanks. I'm surprised a bushing is better than needle bearings, guess the bearings were underspec'd.

 

Nice chart - that gets you some points. But you also lose them because of the misleading title...

It sounded kinky...

And that would have been a better thread.

 

Lifting the truck puts more pressure down on needle bearing, which causes the problem. Some have had the problem without lifting their truck. Some like myself have had no problem, so far with lift. Most replace it. I may have to at Some point.