Hack&Tap Verses Our Modified Stock Shaft


Theirs - vs - Ours

There other conversions out there that leave it up to you to modify your existing out-put shaft by cutting it off, drilling and tapping. This is not something we suggest doing and we believe our modified stock out-put shaft conversions overcome the problems of lesser kits.

We believe the reasons for avoiding the other kits are for sound mechanical reasons. I will outline them for you here.

1. The method of cutting off, drilling and tapping the output shaft of the transfer case while still in the vehicle, is something that I would neither recommend nor attempt myself. We have seen many shafts ruined in this endeavor.

2. After the shaft has been shortened, you will still have a substantial area of unsupported shaft beyond the rear output bearing. I would also consider this to be a problem on a factory original shaft. The result of this is known as "overhung load." The drive shaft which would install against the modified shaft will weigh about 15 pounds while the factory original drive shaft weighs about 9 pounds. This in itself will nearly double the overhung load. We must also consider that under a load, the drive shaft will have a tendency to want to straighten out. This will also increase the overhung load.

3. You should also understand that in order for the new output flange to install on the output shaft, there must be some minor internal clearance between the splined bore of the flange and the splines on the shaft. Because of this clearance, you will then have the potential for minor independent movement between the flange and the shaft. This independent movement, over time (sometimes a very short time) will wear down the splines on the output shaft and enlarge the splines in the bore of the flange. When this happens, it will, because of the looseness between the parts, allow the flange to run eccentric. This will cause a vibration problem with the vehicle. Most people, upon discovering this problem, will re-tighten the retaining bolt. Unless the output shaft has been cut off perfectly square, this will cause the face of the flange to be less than perfectly perpendicular to the centerline of the output shaft. This will usually cause even a more severe vibration problem.

With any of the other conversion kits available, there will be a more substantial shortening of the output shaft, reducing the overhung load. Furthermore on any of the other conversions, the rear output flange or yoke is solidly "sandwiched" between the retaining nut or washer and the rear output bearing. This secure attachment will prevent the wearing of the splines on the mating parts. Thus, preventing the problem as outlined above.