Measuring Your Grand Cherokee 231 or 242 Rear Driveshafts
We can build a new stock type drive shaft for your Cherokee. We will need the length measurement taken from the vehicle with the drive shaft removed and the vehicle resting on the ground.
We also need to verify U-joint size at the differential end.
If you have substantial lift and want the smoothest drive shaft, we suggest one of the Slip Yoke Eliminator (SYE) kits along with a double cardan (CV) drive shaft.
You may need to identify which transfer case you have. This is easily done by looking at the ID tag on the back of the transfer case.
With this system you should be able to keep your transfer case at stock height but you need to be sure to pitch your differential so the pinion points directly at the out-put of the transfer case to maintain minimal joint angle at the differential end.
If you will measure the slope of the drive shaft and the slope of the pinion, we can calculate any adjustment that may be needed. With leaf spring suspension, this is easily corrected with shims placed between the springs and spring perch. If you have coil springs, the adjustment is made with either cam bolts or adjustable control arms.
SplineCount
For the 242 t-case please count the splines on the output of the t-case. It can either be 27 spline or 32 spline
You will also need to confirm the universal joint size at the rear differential (dimension E).
This dimension will be either 3-7/32" or 3-5/8".
You should identify the model of the transfer case.
Is there a port for the shift position sensor in the speedometer housing?
Is the speedometer driven through the transfer case? If it is, the housing will be machined to accept the speedometer driven gear assembly. Or is this portion of the housing cast but not machined?
Measure for length:
If you have a late design transfer case with the rubber boot that attaches to the slip yoke on the drive shaft, measure from the slinger on the rear out-put of the transfer case (this will be the leading edge of the rubber boot) to the center of the universal joint at the rear differential. From this original dimension, we will be able to determine the required length of the drive shaft as an end result.
If you have an early model transfer case, simply measure from the outermost lip of the rear out-put seal on the transfer case to the center of the joint at the differential end. From this original dimension, we will be able to determine the required length of the drive shaft as an end result.
The S spline is a conventional spline stub that will yield a safe, effective and usable stroke of 3”. The X spline is longer than the S spline. The X spline is cut for the full length of the spline stub. This gives a bit more than twice the contact area between the slip yoke and spline stub and a stroke of 4-1/2". This in and of itself will net more than twice the life on these two components.
With the XB configuration, we will use a heavy rubber boot which is banded down with stainless steel banding to seal all of the contaminates out and keep the grease in. The XC configuration uses the same slip yoke & spline stub but instead of using the rubber boot, we drill and tap the slip yoke for a grease fitting and use a dust cap which has convolutions that follow the spline stub for sealing. We consider the XB configuration to be the longest lasting and best value.