My brain hurts can I pick yours??? vin, differential info..etc!

[jeepnmomma]

Opened up the rear differential yesterday and of course some gears are broken (just my luck). Haven't opened up the front yet (doing that in a couple hours) I'm pretty sure the rear is a Dana 44 don't have a clue what the gear ratio is suppose to be though. So whats the easiest way to figure it out and know for sure what the front and rear are? I want to be for sure instead of pretty sure!!!

Other question is...found the vin on the firewall and was wondering what the extra seven numbers under the vin are? Is there a way to figure out what month or when produced (end of year or begining) since mine is the 1986 CJ7 which had 2 different differentials that year. AND what is the deal with the serial number? does it really DO anything?

 

[Old Dog]

If you have the diffs open, you can either count teeth and divide or, the ring gear might be stamped with the # of teeth again divide the #'s to get the ratio.
There's other people here that know more about vin # than I do, so I'll let them answer that.

 

[Buuushman]

This may help you out- look at it in my gallery for a better view- I hope
Or this- you can zoom on P.B.-

 

[IOPort51]

Just about any service manual will help identify the axle and if it is stock it will even give you the ratio. If that fails you could post some pictures of the covers and I would bet we could tell you what they were by the shape.

Opened up the rear differential yesterday and of course some gears are broken (just my luck). Haven't opened up the front yet (doing that in a couple hours) I'm pretty sure the rear is a Dana 44 don't have a clue what the gear ratio is suppose to be though. So whats the easiest way to figure it out and know for sure what the front and rear are? I want to be for sure instead of pretty sure!!!

Other question is...found the vin on the firewall and was wondering what the extra seven numbers under the vin are? Is there a way to figure out what month or when produced (end of year or begining) since mine is the 1986 CJ7 which had 2 different differentials that year. AND what is the deal with the serial number? does it really DO anything?

 

[CJ]

The ring gear will have a # stamped on it such as 41 11, that is the # of pinion teeth and ring gear teeth. just divide for the ratio.

41 /11 = 3.73 ratio

 

[jeepnmomma]

Now i'm really sure its a Dana 44 (cuz of shape and the front is a 30 (i think)) BUT now the weird thing is...there was a plate bolted on the outside cover and it has a long number and then under that it says 3.31 43-13 Um is that right for the gear ratio since it seems kinda high? And what is the 10 digit number above those ones? The front has the same plate with almost every number the same except the last four on the 10 digit number.


ALSO the firewall VIN plate doesn't look like alot of the ones i'm finding..it has a seven digit number under the vin and i'm not sure what that number is for?