Hey i have 4.10s and i recently got upper and lower control arms (non adjustable). The car is not lowered nor do i plan on it, that swhy i i got non adjustable. Anyways, after the UCA and LCA i have had really bad gear whine from the motives (worse than ever) on turns and everything. I went and had it looked at and the pinion angle was fine (they didnt tear apart the rear end to check out the gears though. They have been in for about 2 or 3 weeks. Tomorrow i had planned to take my car to lethal performance in san antonio and have them re-install the gears (because i could have a blown bearing or something aroudn those lines). Now my car is making a knocking noise from the REAR end maybe where the driveshaft meets the gears. It only happens when i am engaging gears and the rear end is taking a small load. If i feather the clutch hardcore it doesnt makea noise. the more aggressive i engage the gear the louder the noise is. What the **** is going on with the car?

 

My guess is that your new UCA and LCA's are more rigid and are transmitting the noise better than your stock ones. Just like a new shifter transmits transmission noise that was there to begin with, but just wasn't being transmitted well enough.

 

the knocking vibrates the car, i can feel it in my seat, it happened tonight, the control arms have ben in the car over 2 weeks, so its not that

 

i think the knocking noise is a blown bushing in the upper control arm :P i think i figured it out. sound right?