rear end gears

[azshtr]

I think my 86 GW has the factory tow package. If so would that mean a LS rear end with 3.31 gears? How can I tell what gears it has?

Thanks

[bigun]

jack it up put jack stand to be safe mark wheel and drive shaft count how many times shaft goes around till wheel goes around once oh turn by hand

[Cecil14]

Jack one wheel up and leave the other on the ground. If it's got an LSD you'll only need to spin the tire once and count the driveshaft turns, if it's an open diff you'll need to spin the tire twice.

Anthony

[bigun]

this will give you an aproxement

[azshtr]

"Jack one wheel up and leave the other on the ground. If it's got an LSD you'll only need to spin the tire once and count the driveshaft turns, if it's an open diff you'll need to spin the tire twice."

So if the diff is a LS it would seem normal regarding tire to shaft rotation, 2.74 or 3.31 and if not LS it would almost seem like radically high gears with only 1 rotation of tire, like 1.35 or so? A bit confused on this method.

[mtn goat]

A better way is to look at the tag on the diff ;)

[bigun]

I believe that every body is assuming that the tag was gone i've only seen 3 maybe 4 for in my life

[azshtr]

"Jack one wheel up and leave the other on the ground. If it's got an LSD you'll only need to spin the tire once and count the driveshaft turns, if it's an open diff you'll need to spin the tire twice."

So if the diff is a LS it would seem normal regarding tire to shaft rotation, 2.74 or 3.31 and if not LS it would almost seem like radically high gears with only 1 rotation of tire, like 1.35 or so? A bit confused on this method.

[bigun]

it is only a rough estimate if you had a three and a half turns on the drive shaft to one turn of the wheel your number would be 3.5 to 1 as some one else pointed out see if the metal tag is on the diff.

[Cecil14]

Originally posted by azshtr:
"Jack one wheel up and leave the other on the ground. If it's got an LSD you'll only need to spin the tire once and count the driveshaft turns, if it's an open diff you'll need to spin the tire twice."

So if the diff is a LS it would seem normal regarding tire to shaft rotation, 2.74 or 3.31 and if not LS it would almost seem like radically high gears with only 1 rotation of tire, like 1.35 or so? A bit confused on this method.Correct. You'll be able to tell if you're close or not. If the shaft only spins about 1.5 times or so then you've probably got an open diff and should try spinning it twice to see what you've really got.

One way to see whether you've got a LSD or not is jack up both tires off the ground and spin one. With a LS I believe both tires should spin the same direction, without they should spin opposite directions. I think that's right but I may have it backwards.

(This is the part where an expert chimes in ;) )

Anthony

[ August 12, 2003, 05:45 PM: Message edited by: Cecil14 ]

[Cliff]

If the rearend is open, the tires will spin in opposite directions.

[azshtr]

After finding the letter stamped on the housing and matching it up with the info here on the web site it turns out that it is 3:15 gears. Thats OK for 31 or 32 inch tires right? I shouldn't have to regear it?

Thanks for all the help

[SpruceMoose]

marginal. i'm running 2.72s with 31s. sloooooow! 3.54 is good for 31s, 3.73s for 33s.

sm.

[Cecil14]

3.15? I didn't think that they came stock with anything other than 2.73 or 3.31...That would probably work with 31's though. I had 31's on my J-10 with 2.73s and it was ok. No speed demon but got about 20mpg with the 258/4speed.

Anthony

[azshtr]

Interesting. I looked at the stamped letter on the AMC20 housing. It is a "B" , then I looked up the chart here on the web site. Thats how I came up with 3.15. By the way what does WLD or LLD refer to on the chart? The chart is in the specs page.