Ring and Pinion

Joined
Apr 11, 2003
Messages
69
Location
Hermiston, Oregon
How can you tell what the Ring and Pinion ratio is (3:73, 4:11) etc. when the gears are still in the differential and the differential is out of the vehicle. I know that if the axle is still together you can turn the wheels and count the turns of the tire compared to the pinion to get the ratio, but these are out of the vehicle so I am not sure. Thanks in advance.
 

e rock

 
 
Joined
Feb 24, 2004
Messages
1,620
Location
Monroe, WA
count the teeth on the ring gear. let this number equal 'x'

count the teeth on the pinion gear. let this number equal 'y'

x/y = gear ratio

41/10 = 4.10

41/11 = 3.73
 
Joined
Dec 26, 2003
Messages
17
Location
Hermiston, OR
I think there are markings on the ring gear that will tell you also. For the most part if they are fine spline pinions that is the only time you could have either of the two ratios. Correct me if im wrong but if it is course unless sombody changed it they should be 4.10. Even when there out you can still mark the ring gear then turn the pinion and see how many turns it takes to make a full rotation.

bulldog: What cruiser do you have here? I just moved to hermiston. I've seen a blue square bezel running around. I have a Dark-ish blue and black 40.
 
Joined
Apr 20, 2005
Messages
360
Location
not the" no", but the F-no CA
you can get an estimate by marking the drive shaft and the tires in one spot each with chalk and then having a buddy drive it slowly. count how many times the drive shaft goes around for the wheel to go once. Almost four times? prorbably 3.73s, alittle more than four times around? 4.11s.
 

FJ40Jim

The Cruiser Whisperer
 
 
Joined
Sep 26, 2003
Messages
10,458
Location
Lancaster, Ohio, USA
e rock said:
count the teeth on the ring gear. let this number equal 'x'
count the teeth on the pinion gear. let this number equal 'y'
x/y = gear ratio
41/10 = 4.10
41/11 = 3.73
37/9 = 4.11
Standard US ratio on E-78 and 88-newer FJ's.

37/10 = 3.70
The standard US ratio for 79-87 models.
 

e rock

 
 
Joined
Feb 24, 2004
Messages
1,620
Location
Monroe, WA
FJ40Jim said:
37/9 = 4.11
Standard US ratio on E-78 and 88-newer FJ's.

37/10 = 3.70
The standard US ratio for 79-87 models.

Thanks for that. I knew my numbers didn't sound quite right for cruisers, but the numbers worked for the purpose of demonstration.
 
Joined
Apr 11, 2003
Messages
69
Location
Hermiston, Oregon
jnau99 - I drive a red with lime green hood FJ40. Most of the time it is parked since I don't have enough seats for the kids.
 
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