Drive line angle and carrier bearing re-location.

[Gekko_hauler]

Read everything I can find about dropping the carrier bearing when putting on a lift. It appears that people try to drop the carrier bearing to try to get the front part of the rear drive shaft and the 2nd part to be in line. However in all of the driveline specific documentation it states that the front piece (jack shaft) should not be more than 1 to 1 1/2 degrees off from the angle of the transmission. All of the lift manufactures seem to suggest the drive shafts should be lined up based on the information of 1/4" shim for each inch of rear lift and using simple trigonometry. The driveline guys and the lift manufactures seem to be at odds here. What did most of the people with lifts actually end up with for carrier drop height for the lift they installed.

Thanks for any feedback.

[caryt]

Shim till its in line...forget trying to use any math.

[TD7667]

Have fun not using math?????

[Gekko_hauler]

Thanks for clarifying that the 2 piece drive shaft should be as straight as possible. Given that the math is pretty simple. An approximately 76 inch drive shaft dropped 8 inches at one end. In order to drop the carrier for a 24 1/2 inch jack shaft to match trig gives approx 2.3 inches drop required. Always wondered why the lift kits never ask whether long bed or short bed (Guess thats what the various shims are all about, as well as tuning out the vibrations) . A shorter drive train in theory requires a bigger carrier drop. The short bed I looked at had a 3 inch spacer. I'm going to start with the 2.3 and go from there.

[Gekko_hauler]

Ended up using 1 inch drop for bearing to get both shafts to be at 7 degrees. This gives working angles of 3 and 2 degrees for the 2 end u-joints. seems to run pretty good.