8" Bulletproof Lift

crownking74 · April 19, 2011

Hey everyone, new on here and just recently purchased a 2010 silverado that has an 8" bulletproof lift on it. I've only had it a while, and theres a noise when engaged in 4-hi. It was just when I would let off of the gas, but now it's even when I accelerate.

I took it to the dealer and they say that it's due to the front driveshaft angle being off.

Any suggestions or help would be appreciated.

blackout07 · April 19, 2011

I'm pretty sure the BP lift is a full drop, so your angles up front should be fine. Not to mention there are tons of others with as much lift and no problems. What type of noise is it? Also, we need pics of this truck.

Matt_ · April 19, 2011

Full drop only means the CVs are flat, the driveshaft angle is still MUCH steeper than stock.

I'd make sure that the diff drop was installed correctly. It should be tapered on one side to angle the pinion upwards towards the tcase.

Matt_ · April 19, 2011

And if its a wining type noise, could be due to incorrect gear install. .... assuming a gear swap was done.

crownking74 · April 19, 2011

I'm pretty sure the BP lift is a full drop, so your angles up front should be fine. Not to mention there are tons of others with as much lift and no problems. What type of noise is it? Also, we need pics of this truck.

I'm still working on getting the pics up, like I said I'm new to this so it's taking a while. The noise originally was a light grinding noise only when in 4 hi and decelerating. Now the noise is a heavier grinding noise and its when accelerating/decelerating.

ruggedlife · April 20, 2011

are you driving in 4hi on the street? thats not good for it... but yeah you probably most deffinitly need a new front driveshaft for an 8inch...

crownking74 · April 21, 2011

are you driving in 4hi on the street? thats not good for it... but yeah you probably most deffinitly need a new front driveshaft for an 8inch...

No I'm not driving in 4 hi on the street, but when it was snowing I noticed it making the noise, so I took it to the dealer to see what they thought it was, and they replaced some bearings in the transfer case, and now the noise is worse. I had to put it into 4hi to let the tech listen to it, and like I said, it sounds worse now. I've been doing some research and someone told me that an index ring might help the noise.

ruggedlife · April 22, 2011

i know for a fact that cognito's 7-9" kit requires a new front driveshaft... you're at 8 inches... sooo by my math you should look into a new front driveshaft. have you called the lift company and see if they have any recommendations?

stlavsa · April 23, 2011

i know for a fact that cognito's 7-9" kit requires a new front driveshaft... you're at 8 inches... sooo by my math you should look into a new front driveshaft. have you called the lift company and see if they have any recommendations?

I dont think you need a front drive shaft for the 8" superlift and I know i didnt need one for my fabtech. Those are both 8" lifts.. Im at like 9 to 9.5" with the extra coil spacer.. no noise..