Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Hello Guest, we are proud to now have our Wiki online that is completely compiled and written by our members. Feel free to browse our Jeep-CJ Wiki or click on any orange keyword when looking at posts in the forum.
Is there anything to watch out for when changing fluids? I know the past owner and owner before him did not. Are there problems resealing, leaking? While in there can I find out the gear ratio?
Make sure the sealing surfaces are clean before re-attaching the covers. The ring gear may have the gear ratio stamped into it. For example: 41-10 would be 4.10 gears. M-20 also has a code stamped on the outside to tell you:
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
As the gears inside may have been changed the best way to be 100% sure is to count the ring gear teeth and divide by the # of teeth on the pinion gears. Don't be alarmed if the front and rear are slightly different, say 3.54 & 3.55, as this matters not at all unless you get over about a .07 difference.
83 CJ7 350 tbi, TH350, D300 twin sticked & clocked, narrowed Chief D44 Eaton Elocker & Moser shafts, Explorer 8.8 Detroit locker, 410's, RE 4.5" spring lift 1" body lift, 35" Claws, cage tied to frame, Corbeau baja seats, HD tie rod and draglink, u-bolts flipped, custom skid plate and sliders, Warn 9.5ti winch with Amsteel synthetic line
1977 CJ 7; Amc 401 .30 over, Howell TBI, modified Dana 20 with Terra Low gears and twin sticks, NV 4500 5-speed, modified Dana 30 and Amc 20 both with 4.56 gears (narrow track), ARB air lockers front and rear, SSBC rear disc brake conversion, MICO Brake park brake, Navaho brake booster/ master cylinder, PowerTank CO2 tank.
Just pay a little extra attention on the gasket for the AMC20 . Sometimes they can be a pain to keep in place while installing the cover. Some just use RTV and no gasket. The Dana 30 is easy to do.
85w-90 gear oil. Plain ol' dino oil or synthetic, your choice.
If you are going off-road a lot and may get into water I would not spring for synthetic as you need to change it often to avoid failure due to contamination.
83 CJ7 350 tbi, TH350, D300 twin sticked & clocked, narrowed Chief D44 Eaton Elocker & Moser shafts, Explorer 8.8 Detroit locker, 410's, RE 4.5" spring lift 1" body lift, 35" Claws, cage tied to frame, Corbeau baja seats, HD tie rod and draglink, u-bolts flipped, custom skid plate and sliders, Warn 9.5ti winch with Amsteel synthetic line
85w-90 gear oil. Plain ol' dino oil or synthetic, your choice.
If you are going off-road a lot and may get into water I would not spring for synthetic as you need to change it often to avoid failure due to contamination.
1977 CJ 7; Amc 401 .30 over, Howell TBI, modified Dana 20 with Terra Low gears and twin sticks, NV 4500 5-speed, modified Dana 30 and Amc 20 both with 4.56 gears (narrow track), ARB air lockers front and rear, SSBC rear disc brake conversion, MICO Brake park brake, Navaho brake booster/ master cylinder, PowerTank CO2 tank.
Ummmmmm...... I counted gears. 43 ring, 14 pinion. 3.07 gear ratio. This may explain why the clutch was so bad, there are 35's on this thing. I should be at least 4.11 even on 33's right?
Ummmmmm...... I counted gears. 43 ring, 14 pinion. 3.07 gear ratio. This may explain why the clutch was so bad, there are 35's on this thing. I should be at least 4.11 even on 33's right?
