Teraflex Extreme Short SYE

Teraflex Extreme Short SYE

If you have a TJ application that has more than 4" of lift and/or a long arm suspension and/or a belly up kit (raised transfer case) this is the SYE kit for you. It will net a drive shaft that is 3" longer than any other SYE kit, which further reduces the operating angle on the drive shaft and allows for more axle droop.

Please also note; with this SYE kit, the speedometer is electronically driven, as opposed to being cable driven. If using this SYE kit in an older vehicle, that has the cable driven speedometer, and if you want a functioning speedometer, you will need to change the speedometer (in your dashboard) to one that is also electronically driven.

To order the SYE as a complete package including the drive shaft, you will need to take a couple of simple measurements. 

The length measurement should be taken with the vehicle parked on flat ground. Your tape measure should also follow the approximate slope of the drive shaft, going straight from point to point (no bend in the tape measure) and it should be done at about the 3 or 9 O’clock positions at each end (center height).

The illustrations below show measuring with the drive shaft in place. If you have no drive shaft in the vehicle the measuring points would be the same.


Note that on some vehicles, there is a harmonic balancer on the rear output shaft. If you have this, you should still measure from the forward edge of the rubber boot, to the centerline of the universal joint, at the differential end.

You may also need to confirm the universal joint size at the differential end. Assuming stock differentials, the YJ through & including 1993 versions and all TJ applications, the universal joint size will be a 1310 series. On the 1994 & 1995 YJ the universal joint size will be a 1330 series. On most XJ applications, the universal joint size will also be a 1310 series. For the XJ, ZJ & WJ, we will require that you confirm the universal joint size, at the differential end of the drive shaft. Per the art below, the E dimension on a 1310 series universal joint is 3-7/32" (3.219"). The 1330 series universal joint will have an E dimension of 3-5/8" (3.625").

Final thoughts:

For the double cardan drive shaft to run smoothly, it is important that you rotate the differential so that the pinion points directly at the output of the transfer case (maintaining 3 degrees, or less, joint angle at the differential end). For example; if the slope of the drive shaft is 15° the pinion should be between 12° and 15°. With 13° or 14° being ideal. Again, this is just an example and your actual numbers will probably be different.

On any vehicle with coil springs, any adjustment is most easily accomplished with adjustable control arms (minimal amounts of change can be effected with cam bolts). On any application with leaf springs, this adjustment can be accomplished by either cutting & welding the spring perches, or with tapered shims, that are placed between the spring pack & spring perches.

We do offer some, very nice, steel shims for this purpose. In order to determine how much shim you would need, we would need to know the current length of the drive shaft along with the slope of the drive shaft, and the differential pinion. Please refer to this link for a simple method of determining these slopes. If you have no drive shaft in your vehicle now, you can simply run a string line from the transfer case flange/yoke to the pinion flange/yoke. This will simulate the slope of the drive shaft.

You should also consider replacing the straps & bolts, that attach the universal joint to the pinion yoke. The reason for this is; the bearing straps are designed to draw down and securely clamp the universal joint into the pinion yoke. After repeated use, the bearing straps lose some of this draw down effect. We do offer new strap & bolt kits for only $6.00.

If you have questions, or would like to place an order, please contact us.