Venture Rear End Swap

by Ken Boerman


I have swapped the the rear ends  (differential - secondary reduction).  So far I am pleased with the results.  I think the Venture benefits most from the swap. It is much easier to get the big boy moving now from stop lights. Although 5th is a little busy, 65mph is comfortable and it is turning 4500rpm at 75mph. Unofficial 1/4 mile speed 100mph.

  Vmax 85  Venture 89
Primary Reduction   1.775 Same
Secondary Reduction    2.851 2.566
1st gear   2.529 2.600
2nd gear    1.772 same
3rd gear  1.347 same
4th gear  1.076 1.068
5th gear    0.928 0.906

Mr. Max has plenty of power to pull the higher gears and is more comfortable at cruising speeds now. After riding it awhile I don't notice the difference anymore.  Top speed at 5000 foot elevation was 135 in 4th gear. I didn't try 5th so am not sure if I could have brought it up any more.


NOTE: All years Venture and Royal Star differentials should work, although some don't have the stud for the rear shock mount and some have hole for electronic speedo drive pickup. Avoid early model (pre-85) Venture diffs.