Numbers & letters on rear Diff

[johnypreflt]

ok I am trying to figure out what gears I have and there is no id tag. so what do the numbers 428 and the letter Z or N depending on how you look at it? :confused:

[woodybeone]

Assumption here.
If it is the rear and an AMC 20 then an "N" is the 3:54 ratio Track-Loc narrow track.
The 4/28 is the build date.

To check, take a piece of chalk and mark the tire at 0600 and put a parallel mark the drive shaft or tape a piece of string. Rotate the tire exactly one rev. and count the times the hash mark passed or the number of rev's of the string around the drive shaft.

[Stuka]

When you do what woody said you need to have 1 tires on the ground (otherwise the other tire will spin in the other direction unless the trac-loc actually works). Or...have both tires jacked up, and turn the drive shaft until the tires make one revolution.

Now, no 80's FSJ came with 3.54 gears. Wags, cheros, and J10's came with 2.73 or 3.31's. The J20 came with 3.73, 4.10, or 4.88's.

[Brown Bear]

http://www.ifsja.org/tech/axle/axleid.shtml

[johnypreflt]

thanks for the info guys, but maybe I am looking in the wrong spot the numbers that I am talking about are on top center of the diff. not along the axle tube or rear cover

[Stuka]

ahh...wrong numbers smile.gif

the rear axle will be an M20, the code letters will be stamped into the right (passenger) side of the center dif where the tube goes into it. The site that bear posted has it i think.

[johnypreflt]

the only problem is I cant find any nubers by either tube