I am in the middle of installing a NP540 tranny in my '57 FF PW. Because this tranny is longer than the NP420 it is replacing, I need to shorten the jack shaft (shaft between tranny and transfer case) or use a different one. I need to remove 2" from an original shaft. Has anyone shortened one this much?? Is it still a strong joint?? Any help in avoiding problems is appreciated.
Jimbo.

Posted by Peter Sprouse on Sunday, November 03, 2002 at 10:09PM :
When I did the same swap you are doing, I installed a very short, but heavy duty Spicer jackshaft. I might be able to find those numbers for you.

Here are the Spicer part numbers I used for the NP540 to NP200 driveshaft:

Driveshaft, 1412 series: 3-2-159 and 3-3-1511KX (male and female parts)
U-joints: 5-160X
Transmission flange: 3-1-2431
Transfer case flange: 3-1-751

The male part of the driveshaft had to be cut down by 1/2 inch or so at a machine shop to allow for freeplay in this very short application.

Peter Sprouse