Subject: Determining rear end without tags Author: doug : member since August, 2005 : 47 posts Posted on: 2005-10-17 09:14:44

Just wanted to pipe in here and share a trick that my pops showed me. If you want to determine the ratio of any diffy, mark either, left or right output flange (the half shafts bolt to them, aka output shaft) at the 12 oclock position and do the same with input shaft (shaft in front where driveshaft bolts up) using tape, chalk or somthing you can easily see.

Now your ready for the raito. With all the marks made on the input and output shafts and flanges, make sure they are pointing at the 12 oclock position, we will start by turning the input shaft either direction and watch the output shaft also turn. In order to figure out the ratio we simply count the number of rotations needed to turn the input shaft in order for the output shaft to completly make one (1) rotation. So if I had to turn the input shaft 3 turns plus the mark continued to say the one (1) oclock position, the ratio would be close to 3.07. If the input shaft was turned 3 complete reveloutions and then stopped almost the 6 oclock position then the diffy is 3.46.

You can use this method to identify the ratio of any gear box including manual transmission. If you are to use this method for a transmission, just put into the gear you want to measure and turn input shaft while watching output turn one complete revolution.

Hoped this helps.
Doug

• Determining rear end ratio and diff types. - kff 2005-10-09 14:02:28 (293 views)
  • Determining rear end without tags - doug 2005-10-17 09:14:44 (121 views)
  • Re: Determining rear end ratio and diff types. - kjkumar 2005-10-09 15:12:31 (139 views)
    • Thanks Keith, I think this clears things up a bit (nt) - chad20 2005-10-10 15:04:02 (91 views)