Is my rear drive shaft too long?

Capt. Bawls McSalty!

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Klien Texas
I just bought this Jeep and thought all it needed was sway bar bushings. As I was replacing them I noticed that the bolt for the driver side connecting link to frame was loose, then I noticed that the bolts on one side of the straps that were holding the U Joint to the pinion yoke were loose. tightened all that down and finished replacing the bushing and while it is much better it still seems a little wiggly back t

Slip Yoke.jpg


Dive Shaft.jpg


Slip Yoke.jpg


Dive Shaft.jpg
here. Got pics of the drive shaft. Thanks in Advance
 
Had another guy (who drag races 4x4's) tell me it's too short and that's why when I step on the truck ( like I'm climbing in) with the drive shaft connected. the rear tire rotates backward about an inch" When I disconnect the drive shaft from the axle it doesn't do it.
 
The driveshaft length isn't causing the rear tire to rotate backwards an inch when you step on the Jeep. But with you guessing it has 4" of lift are you having any drivetrain vibrations? Is your transfer case skidplate dropped down from the frame with spacers which is done to stop/reduce vibrations?

To know for sure what suspension lift height is installed measure your front and rear rear spring heights. Stock up front spring height is 12", 8" in the rear. Any height above those numbers is your suspension lift height.

Show us a photo of one of the body mounts between the frame and body, we can tell you how much, if any, body lift height you have.

With 4" and taller suspension lift heights it's time to install a slip-yoke eliminator (SYE) kit and a rear DC (double-cardan) driveshaft. That gives more room for a longer driveshaft and reduced drivetrain angles to eliminate vibrations. That modification also requires adjustable length rear control arms so the pinion angle can be set properly for the DC driveshaft which requires a different pinion angle from the OE driveshaft.
 
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So my Front spring measures 15" and the rear is 11". I don't have any vibration or grinding, But when I accelerate or decelerate the jeep seems to move like It's flexing from the rear. I replaced the really worn-out sway bar bushings and that helped a lot, but I can still feel it. I also feel it while driving over uneven surfaces. (Never Had in the Dirt yet) like like patched-up roads. Seems to steer fine, doesn't pull or anything. I have had it up to 80 and it seems to steer true without any wobble. Also when I let out the clutch from a dead stop I can feel the jeep lift. My plan is to replace all the bushings in the back and then move up front. It has a newer front sway bar (Disconnecting & Adjustable) connecting links but the sway bar bushing themselves seem pretty worn.

Front Spring.jpg


Rear Shock.jpg


Transmission Pan.jpg


Body Mount.jpg


Captain Bawls McSalty.jpg
 
So my Front spring measures 15" and the rear is 11". I don't have any vibration or grinding, But when I accelerate or decelerate the jeep seems to move like It's flexing from the rear. I replaced the really worn-out sway bar bushings and that helped a lot, but I can still feel it. I also feel it while driving over uneven surfaces. (Never Had in the Dirt yet) like like patched-up roads. Seems to steer fine, doesn't pull or anything. I have had it up to 80 and it seems to steer true without any wobble. Also when I let out the clutch from a dead stop I can feel the jeep lift. My plan is to replace all the bushings in the back and then move up front. It has a newer front sway bar (Disconnecting & Adjustable) connecting links but the sway bar bushing themselves seem pretty worn.

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Looks like you have 4" lift springs and you have spacers on top of the height of the springs (front). Probably to level it.
 
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No body lift, looks like a 2" spacer between the tcase skidplate and frame. 6" of suspension lift from combining 4" taller springs with a 2" spacer (which I would remove). You could get rid of the tcase spacer to pick up 2" of additional ground clearance by installing the SYE kit and DC driveshaft.
 
Thanks, I am going to get an SYE. Right now I'm replacing the rear track bar and control arms to see if that alleviates the movement in the back. Do I need to raise the jeep off the ground to do this? I was going to pull each part off then measure from center to center of the old part then adjust new parts accordingly then take it to the shop for alignment. Instructions want me to raise the jeep and remove the springs? Thanks in advance for any advice I can get!
 
No body lift, looks like a 2" spacer between the tcase skidplate and frame. 6" of suspension lift from combining 4" taller springs with a 2" spacer (which I would remove). You could get rid of the tcase spacer to pick up 2" of additional ground clearance by installing the SYE kit and DC driveshaft.

Thanks for the advice! Do I need to Lift the Jeep to change out the upper and lower control arms? I am new to forums and still trying to navigate around. Thanks again!