what's my R&P ratio???

[ctToyBoy]

so, I have a 1994 toy PU, 4x4, V6, x-cab, and I'm trying to figure out what my ring and pinion ratio is.  In 4th gear, I get up to 65 mph @ 3300 rpm's.  Any Marlin folk have an idea.  I thought it was 4.10, but I may be wrong.

[M1]

If your R&P is stock, you should have 4.38 if you have a manual trans or 4.10 if you have an auto.

[ctToyBoy]

4th gear should be 1:1 right.....

[Marlin]

Posted by: lcrunner  Posted on: Today at 08:19:06pm  
If your R&P is stock, you should have 4.38 if you have a manual trans or 4.10 if you have an auto.

I have never heard of a 4.38, there is however a 4.37 r&p found in the 79-80 20R 4x4s. If your V6 is a 5 sp, you would have a 4.10, unless you have the big tire package, then they were 4.56's. Auto pickup's were 4.10's and all auto 4 runners were 4.88's. The rpm's will change depending on the tire size.
A quick way to find your gear raito on a open rearend, is to turn one tire two times and count the drineline rotations. This will be your ring and pinion ratio. With a locker, turn both rear tires one time, and count the driveline rotation.
All Toyota 4x4 have a 1:1 4th gear.  Marlin

[ctToyBoy]

thanks for the advise, Marlin.  I'll jack up the axle and check it out tomorrow.  My only reason for being confused was i didn't know if the 31's that were on the truck were the factory option, or were added later.  

[ctToyBoy]

ohh yeah, almost forgot.  Does my first post provide any clues:

3300 rpm @ 65 mph in 4th gear(5 speed manual transmission) with 31 x 10.5 BFGoodrich AT's(95% tread)

[Marlin]

thanks for the advise, Marlin.  I'll jack up the axle and check it out tomorrow.  My only reason for being confused was i didn't know if the 31's that were on the truck were the factory option, or were added later


Sercure the truck so it wont row and jack up one rear tire. Being right handed, I use the drivers side rear tire. Rotate the tire untill the valve stem is closest to the ground and then make a mark on the diff flange dust shield and the cast iron diff housing. Using your right hand, rotate the one tire 2 complete rotations. When the valve stem returnes to the ground at rhe end of the secound rotation, the amount of driveshaft rotations and the part of complete rotation will be your r&p ratio. 4 turns and a tenth is a 4.10. 4 and one half would be a 4.56 ect.
Marlin