Figuring rear end ratio's!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[gpnavar]

Hi guys I'm having a problem because I can't seem to get these figures to work out and I can't find an explanation on the net telling me how to figure the final gear ratio on the project that I'm working on right now. I have the rear end blocked up both tires off of the ground the drive line is not attached to the rear end either. So I mark the yoke on the driveline and I mark one tire and rotate the tire a full 360 degrees one turn and the differential yoke turns 1 3/4 turns. Now would someone please tell me what divides into what or multiples to make this a 3 something ratio. I read a post somewhere else that a guy had the same results as I did and they agreed that he probably had a 3:55 ratio but I have no idea how they made that decision. I'm looking froward to your explanation and than you in advance for your help. Gary

[1BAD68]

I have the rear end blocked up both tires off of the ground the drive line is not attached to the rear end either. So I mark the yoke on the driveline and I mark one tire and rotate the tire a full 360 degrees one turn and the differential yoke turns 1 3/4 turns.

I dont think you are doing this right, you need to block one tire so it doesn't turn and then turn the other one and count the rev's.
As it stands you have 1.75's so I'm betting that if you do it this way you'll end up counting 3 1/2 turns which would be 3.55's

[John_Kunkel]

The easiest way is to block one tire and turn the other one two full revolutions while counting the yoke turns.

[1BAD68]

The easiest way is to block one tire and turn the other one two full revolutions while counting the yoke turns.

Doh! I knew I forgot something

[gpnavar]

Ok guys here we go first off I turned either tire and the other one is independent and does not turn so I assume that it is an open rear end. I tried one turn on the tire and I tried two turns on the tire I even tried this with both tires and it always comes up the same if  I turn the tire one complete revolution I get 1 3/4 turns at the differential yoke if I turn the tire two complete turns I get les than 2 3/4 turns at the yoke it appears to be about 2 5/8 turns so I give up I have no idea. Any other suggestions? I look forward to your comments. Thanks again guys. Gary

[1BAD68]

if  I turn the tire one complete revolution I get 1 3/4 turns at the differential yoke if I turn the tire two complete turns I get les than 2 3/4 turns at the yoke it appears to be about 2 5/8 turns so I give up I have no idea.

there's some slippage going on there, if you turn the wheel two times it should be twice the value of one turn.
I wouldnt assume its an open diff unless the other wheel spins opposite, if it just sits there then something is slipping in the rear end.