I've got a 02 sierra extcab lowered 3/6 with Mcgaughy springs and flipkit, also has the 2 piece driveshaft. Let me start off sayn the carrier bearing has been raised 1/2 inch and it already has 6* shims in the rear BUT it still vibrates from 10mph up till 30-40mph depending how hard I accelerate... I checked the pinion angles if I read the angle finder correctly and its sayn -2* on the 2nd driveshaft and +2 on bottom of diff housing. Im totally confused on how to solve this issue, can anyone point me in the right direction... do I need to remove the 6* shims or drop carrier back to stock height? Thanks in advance!!!
3/6 drop, NEED HELP WITH PINION ANGLES! HELP HELP HELP
- Thread starter 01droppedsilvy
- Start date
Take out the shims and measure your angles after that.
Measure where the driveshaft meets the tranny and again at the rear like you did. It should be equal, but opposites like you posted.
Measure where the driveshaft meets the tranny and again at the rear like you did. It should be equal, but opposites like you posted.
2 piece driveshaft is much more complex then a 1 piece. First you need to get your front shaft to align to a true operating angle of 1-1.5 degrees. To do this you need to measure off the bottom of the yoke off the trans output shaft. Then measure the angle of the first shaft. If the yoke is 5*, the first shaft must be either 4-3.5* or 6-6.5*.
Once that is found and corrected, you need to then re measure the front shaft angle. IF it is now 4-3.5 or 6-6.5 you match the rear end yoke to that. So if we say the front half shaft angle is 4* down, you need to make the rear end 4* up. Or vise versa
Or just put shit in and out all willy nilly like everybody else does, then give up. Either way
Once that is found and corrected, you need to then re measure the front shaft angle. IF it is now 4-3.5 or 6-6.5 you match the rear end yoke to that. So if we say the front half shaft angle is 4* down, you need to make the rear end 4* up. Or vise versa
Or just put shit in and out all willy nilly like everybody else does, then give up. Either way
Last edited:
i'm not gonna give up got to much $$$ in it lol I just wanna get it fixed and wasn't sure how to go about it. Just so i'm 100% clear if i'm holding the angle finder on bottom of the rear diff and the needle is pointing towards the rear bumper that's + and if its towards the front that's - correct? so basically what your sayn is whatever my front shaft reads at I need to make the rear end read the same or vice versa and do not bother with the 2nd shaft?
Exactly. One the Rear end and first shaft are in synce, the 2nd shaft is automatically set.
You need to put the angle finder on the yoke of the output shaft tho, not on the housing. Using a socket on the ujoint sure helpsm Make sure its on the ujoint cap that is fixed to the rear end, not the cap fixed to the shaft
You need to put the angle finder on the yoke of the output shaft tho, not on the housing. Using a socket on the ujoint sure helpsm Make sure its on the ujoint cap that is fixed to the rear end, not the cap fixed to the shaft
ok so I checked everything again and its saying tail shaft -1.5, first shaft -2, 2nd shaft -2, rear diff yoke +5 and that's with 6* shims in the rear and the carrier bearing lifted 1.5"..... Should I try raising or lowering the carrier bearing or go with different shims in the rear??? My brain is fried trying to figure all this out lol
Your front operating angle (1.5* - 2.0*) is onloy .5* degree. Needs to be 1-1.5*. I would lwoer the carrier until the front shaft sits to - 2.5-3* that way it give you the require operting angle. Once thats done, get a smaller shim in the rear end to bring it closer to +2.5 to 3*.
Probably a 3 degree shim and you'll be golden once you lower carrier
Probably a 3 degree shim and you'll be golden once you lower carrier
That's exactly how I feel!
- - - - - - - - - -auto merged double post- - - - - - - - - -
Thank you for all your help!!! I'm gonna do that tomorrow!