Which is the right differential ratio?

[Chriss]

Hello,

which is the right differential ratio for my CJ7 ?

360 engine
T-150 3 speed manual
33" wheels
AMC20 rear axle and Dana 30 front axle
The old ratio is 2.73 . I think a 4.11 is good for driving offroad too? Or is a 4.56 better?

 

[Les]

Hello,

which is the right differential ratio for my CJ7 ?

360 engine
T-150 3 speed manual
33" wheels
AMC20 rear axle and Dana 30 front axle
The old ratio is 2.73 . I think a 4.11 is good for driving offroad too? Or is a 4.56 better?

Here is a chart, so you can pick what is right for you. I would imagine that your old ratio was 3.73

Jeep Ratio Calculators

 

[Incommando]

If you drive it on-road as well I would stick with 4.10/4.11. The 1:1 3rd gear is the main rationale. I would go 4.56 with an O/D tranny. If it is almost all off-road you could get away with 4.56's easily.

Go to www.grimmjeeper.com & enter both combos to see which you think gives you a better range for how you actually use your jeep.

 

[Chriss]

Thanks, but the old ratio is really a 2.73. It´s a 85 CJ wide track axle with inline 6 from California. It is the longest ratio ever build in CJ´s. I believe it was for the stronger pollution control in California?
I have a second pair of small track axles from a 79 CJ also with a inline 6 but from Canada. These axles have the 3.73 ratio.

 

[Chriss]

If you drive it on-road as well I would stick with 4.10/4.11. The 1:1 3rd gear is the main rationale. I would go 4.56 with an O/D tranny. If it is almost all off-road you could get away with 4.56's easily.

Go to www.grimmjeeper.com & enter both combos to see which you think gives you a better range for how you actually use your jeep.

Ohhh, thank you. What O/D tranny would you recommend? One of my JEEP drivers have a ATLAS tranny in his CJ5 . Is this kind good?

 

[csuengr]

Atlas is a Transfer Case , not a Transmission . An Atlas is an aftermarket only Transfer Case . Not stock in anything.