Driveline Vibes after Deaver U402 Rear Spring Install

2018 TRD Pro. Stock suspension setup was my baseline, with RSI Smartcap. Rear end was squatting as the springs had settled quite a bit. Installed Deaver U402 rear leafs (stage 2) to correct the squat and increase load capacity for my RSI Smartcap and RTT (to be installed). As soon as the leafs were installed, there was a significant driveline vibe. Most pronounced at 20-40MPH of acceleration, and as bad as a near shudder down to 10MPH when decelerating. No change when switching into 4HI.

I've searched, and with no change when in 4HI, it seems like this is not the driver needle bearing issue? Is this just driveline and diff pinion angles far enough off now with the rear end lifted?

The real question - can I kill this dead with the Eibach TRD Pro front springs + the ECGS bushing?

 

Its the driveshaft angle. The stage 2 leaf packs give 2" of lift with a constant weight of 600lbs. Your front has no lift so it puts the driveshaft at a bad angle.

 

Axle shims. Rule of thumb is a degree per inch of lift. You may also try carrier bearing drop.

 

Thanks for the replies. Putting in the eibach front springs should help, right?

 

Not with rear driveline angles. You need to address that separately. Shims and or carrier bearing drop. Raising front will not change anything on rear.