gears for amc 20 and dana 30

[79cj7bogger]

planning on doing a one piece shaft swap in the 20 and wanting to re gear both but not sure which gear to go with as i do drive around town and and back roads but will be hitting up mud runs the river and jeep jamborees. any advice on gear selection is appreciated.

 

[NorthwestCJer]

Loaded question, What are you running now for gears? what tire size do you have or do you plan on having? what Transmission ? what engine? There are lots to consider when chosing gears.
I run 4.10's with a T177/Dana 300 in a 84 CJ7 on 33 inch tires, behind a AMC 258 i6 / 4.2l . It fits for me both on road and off!

 

[79cj7bogger]

AMC 258 i6 / 4.2l T-150 Dana 300 and stock gears now 33x12.5 maybe a 35 later on but eventually gonna be slow driver round town mainly offroader i know im gonna either ox lock the front n rear or truetrac it

 

[79cj7bogger]

sorry thinkin of wrong jeep this ones got the Dana 20 tcase

 

[BusaDave9]

Check out this chart. Tire size on the left. Gearing on the top. Engine RPM at 65 mph in the middle. To keep factory gearing shoot for the green. Since you are more concerned with off-roading you may go to the red for lower gearing.

You may want 4.1 to 4.56 gears. Since you plan in getting 35's I would go with 4.88.
I have a CJ5 with 36 inch tires and I do just fine on the highway with 4.88 gears. As a matter of fact I wish I had lower gears. I also use my CJ mainly for off-roading.
That's what I say: 4.88
Yes, that's my final answer.

 

[Old Dog]

If it's for off road and just going slow around town I agree with Dave, 4:88's.
Of course this is from 2 people that like to play in the rocks, if your a mudder 4:10s might be better.
You need a little wheel speed for the mud.

 

[gp4play]

go 4.56 on/off road, 4.88 off road. I run 4.56's with OX lockers at both ends, 34" swamppers and love it.

 

[79cj7bogger]

thanks for the advice and for the chart was flip floppin between 4.56 and 4.88 but wasnt sure about rpms if i ever did hit short distance on highway

 

[79cj7bogger]

If it's for off road and just going slow around town I agree with Dave, 4:88's.
Of course this is from 2 people that like to play in the rocks, if your a mudder 4:10s might be better.
You need a little wheel speed for the mud.

was thinkin that at one time but my buddies dad is runnin 5.13 in his CJ5 and he gets along good in mud and river