cj gear questions

[jasonvess]

I have a 1983 Jeep CJ7 258 6 cyl, 4sp manual dana 30 front axle/amc 20 rear.

Does Anyone know what the stock gear ratio was in these axles?

What would be a good all around gear for some highway, some trail driving with 35's?

I don't want to lose my jeeps drivability on the highway, but i want to regain some of the lost low end power. I was thinking 4.10's, any suggestions?

 

[far_right]

stock is prob. 2.73. 4.10s would be good for 35s

 

[jasonvess]

great thanks for the quick answers

 

[wenz78Cj5]

I have just put 35's on my CJ and changed the gears to 4:56's. I have the 258 Straight Six and have found that the highway speed is good, but it still cr crawls a little to quick. I was recomended 4:56 so that the highway speed would still be good, yet offroad it would still do well. If you really want a good crawl ratio, go with 4:88's, but if you want to keep up you highway speed, I would recomend 4:56.
-Wenz

 

[avyoung]

AMC 20 spool or welded gears

You may have 3.07 or 3.54 also both came stock. I would look for the tag on the front axle. I could not find one on my rear. There are also 2 other ways to find out. I Just went through this with my axles.

If you have an open diff the first didn't work for me, but with my new axle with a locker it did. turn the tire and count rotations of the driveshaft.

The second way is to open up the cover count ring teath and divide it by pinion teath. The best way is to find the tag.

 

[wm69]

look on the rear gear housing to the right of the pumpkin and there is a letter stamped on it. This tells you what gears you have and whether or not you have a limited slip. Do a search on this site as the codes and corresponding gear ratios were posted about a month ago (by me, but lost the link).

 

[jasonvess]

well everybody, i did the turn the tire thing and count the driveshaft, since i can't find a code on the rear axle, and the tag is not readable on the front axle.

The Driveshaft made just a little more than 3 1/4 turns to the tires one turn, so i am assuming i probally have the 3.31 gears.

But this only worked on my front axle which has a detroit locker in it, the rear axle doing this way showed just under 2 turns of the of the driveshaft to one turn of the tire?????

The gears are stock and have not been changed, so would this mean i have a open rear end or a limited slip.

It leaves 2 tire marks if i spin them in dirt, not just one, i would think it is a limited slip rear end???

 

[avyoung]

You need to put one tire on a slippery serface and one on a hard surface then see if both spin. If both wheels have the same traction they will both spin. You can get on dirt and turn while hitting the gas and then you can sometimes find out if it is an open differential.

If I were you I would pull the cover and count teeth if you want to know exact. If you are just curiouse then you are probably close.

 

[Sully]

stock is prob. 2.73. 4.10s would be good for 35s

Thats what I was thinking.I would think 4.88 for 35's.But thats just me.If you are not really going to be wheeling.4.56 would be good for highway speeds and still have down low power.I just like low gears.

 

[wm69]

Look right here on your rear axle and there is a letter stamped on the housing. You will probably have to scrape mud/grease off but it is there.

http://www.imagestation.com/mypictu...ion=ebay 025&album_id=4289080121&from_album=1

Here are the codes. I had to take a wire brush (groove brush for golf clubs) and clean my rear axle to see the code.

Narrow Track AMC 20
: Code Gear Ratio Diff Type
: AA 2.73 Open
: DD 2.73 Trac-Lok
: BB 3.31 Open
: CC 3.31 Trac-Lok
: A 3.54 Open
: N 3.54 Trac-Lok
: GG 3.73 Open
: Q 3.73 Trac-Lok
: L 4.10 Open
: M 4.10 Trac-Lok

: Wide Track AMC 20
: Code Gear Ratio Diff Type
: D 2.73 Open
: DD 2.73 Trac-Lok
: B 3.31 Open
: BB 3.31 Trac-Lok
: A 3.54 Open
: AA 3.54 Trac-Lok
: H 3.73 Open
: HH 3.73 Trac-Lok
: C 4.10 Open
: CC 4.10 Trac-Lok

 

[Sully]

1987 wrangler odd?

If you find a double digit you have trac lok.