Vibrations after 2/1 lift

Hoping someone can help me out… I have a 22 TRD Sport that I put a 2/1 spacer lift in. 2 inch mammoth spacer up front, 1 inch tapered spacer in rear from low range off-road. I am experiencing vibrations between 20-30 mph but most prominent at 25 mph. I had a regular one inch lift block in the rear but I read that shims would probably fix my issue, so I installed the 1 inch, 1 degree block from low range off-road… no luck. It happens while decelerating, and while holding my speed at 25 mph. It causes an audible vibration and you can also feel it in the wheel. It is the worst when decelerating quickly in that speed range. I have tried the old man emu carrier bearing drop as well as washers. Nothing seems to cause a drastic difference. I have seen the thread about ECGS bushing however when I switch to 4wd it is still there, so I wasn’t sure if that meant it was NOT the needle bearing. Any help would be so appreciated as it is a brand new ride and really bumming me out. If I didn’t just spend so much on rims and tires, I’d probably just go back to stock.

 

I assume everything is installed correctly. It's your driveshaft angles. Just guessing and installing a 1 degree axle shim doesn't mean anything. You have to measure your shaft angles to determine which degree of shim you need. Then you might also need to shim down your CB. There is no plug n play way. You have to do your homework.

 

4x4 mode. Does it go away?

 

Thanks for the responses, I am new to forums so I wasn’t quite sure if I should post a new thread or put it on an existing one so I appreciate the answers. So I did a BUNCH of research before posting. I have purchased an angle finder, as well as trying the OME CB drop upon initial install. Everything is torqued to spec, I installed the 1” tapered lift block after the normal flat 1” block performed the same. and I saw you typically do 1 degree for every one inch of lift. From what I saw, I believe my rear pinion angle is around 3 degrees. However the calibration on my Klein angle finder was very shaky. I did read the big write up on driveline angles and tried to do it the same exact way. I tried the OME CB drop, as well as just some washers. No obvious change. The issue does not go away when switching into 4wd, which is why I thought maybe it was not the needle bearing. I only did a 1 degree block because I wasn’t sure if it was safe to stack a block and a shim. When I put in the OME CB drop the first and second driveline angle we’re almost exactly equal around 4 degrees. I believe my rear pinion was at 3 degrees. No obvious difference. Contemplating taking the spacer lift out and doing bilstein 6112/5160 as well as an icon 1.5” AAL. Let me know what you think. Thanks.

 

I know it might be a stupid comment, but I saw a YouTube video where the guy installed the shims backwards. The fat side goes towards the back end of the truck. You might also try a carrier bearing drop

 

I made sure the skinny end was towards the front, the blocks I ordered had an “f” on them too so I made sure that got installed correctly. I have also tried the cb drop.

 

You mentioned rims and tires. What did you buy? Might not be your lift at all. If you have a more aggressive tire that vibration could simply be the tires

 

I bought Nitto ridge grapplers, however the vibration was there before the new tires were put on