Please help identify this axle!!!

[stretch-bsn]

I was told this came off a 2022 JLUR however it has steel knuckles and what looks like a factory FAD delete?

Please help!

Sponsored

 

[jadmt]

does it have CV axle shafts or ujoints? maybe the2022 392's had fad delete and steel knuckles?

 

[stretch-bsn]

does it have CV axle shafts or ujoints?

This is the best picture I have at the moment. I don’t think it’s CV but it’s not clear to me.

 

[jadmt]

not CV's which would have made it a 2024 or newer. I bet someone with a 392 can tell you if they had fad deletes and steel knuckles.

 

[Zandcwhite]

I think only the xrs got steel knuckles which means I'd jump all over it if you're looking for a front axle upgrade. Even if you want to keep your FAD you can move it to the new axle.

 

[stretch-bsn]

I think only the xrs got steel knuckles which means I'd jump all over it if you're looking for a front axle upgrade. Even if you want to keep your FAD you can move it to the new axle.

Well the problem is I did jump all over it lol…I already bought and installed this axle and the rear however I want to make sure my gearing is correct….the guy told me they are 4.10s then ghosted me after I purchased them…so I have zero knowledge about what they came off other than what he said but the story doesn’t add up. The rear brakes also say “392” on them but it’s still not clear. I geared if for 4:10’s with Jscan but it seems worse than my stock 3.45’s with 35’s so I’m wondering if I have the computer programmed for the wrong gears.

That’s why I posted the stickers…I think it should be identifiable through those right?

 

[Zandcwhite]

Well the problem is I did jump all over it lol…I already bought and installed this axle and the rear however I want to make sure my gearing is correct….the guy told me they are 4.10s then ghosted me after I purchased them…so I have zero knowledge about what they came off other than what he said but the story doesn’t add up. The rear brakes also say “392” on them but it’s still not clear. I geared if for 4:10’s with Jscan but it seems worse than my stock 3.45’s with 35’s so I’m wondering if I have the computer programmed for the wrong gears.

That’s why I posted the stickers…I think it should be identifiable through those right?

Steel knuckles to me say xr, which means 4.56 gears. 392s were either 3.73 for non-xr or 4.56 for xr models.

 

[jadmt]

pull the diff cover and count the gears...you can also jack up the back and turn the rear tire while have someone count the rotations of the driveshaft...to be most accurate spin the tire say 10 times and count the rotations of the drive shaft...if it has 4.10's the drive shaft will have rotated 410 times...if 373 times 3.73's etc.....

 

[jadmt]

also you would have probably went in limp mode if you programed for 4.10's and it had 3.73 or 4.56

 

[Zandcwhite]

also you would have probably went in limp mode if you programed for 4.10's and it had 3.73 or 4.56

The shift points would be off and the speedometer would be off, but why would it go into limp mode? It's no different than driving after going to bigger tires without reprogramming. The Jeep doesn't have a reference point for what the wheel speed should be. Just an algorithm for what it is and the incorrect gear size in the computer will simply throw off that math and nothing more.

 

[stretch-bsn]

Steel knuckles to me say xr, which means 4.56 gears. 392s were either 3.73 for non-xr or 4.56 for xr models.

They made 392’s with aluminum knuckles?

 

[stretch-bsn]

pull the diff cover and count the gears...you can also jack up the back and turn the rear tire while have someone count the rotations of the driveshaft...to be most accurate spin the tire say 10 times and count the rotations of the drive shaft...if it has 4.10's the drive shaft will have rotated 410 times...if 373 times 3.73's etc.....

So I know pulling the diff is the sure fire way but was trying to avoid this seeing how I just put new gear oil in it (yeah I know that could be lazy of me I just figured there may be a less invasive option).

We did jack it up and spin it seemed like 2 tire rotations gave us about the 4.10.

 

[stretch-bsn]

The shift points would be off and the speedometer would be off, but why would it go into limp mode? It's no different than driving after going to bigger tires without reprogramming. The Jeep doesn't have a reference point for what the wheel speed should be. Just an algorithm for what it is and the incorrect gear size in the computer will simply throw off that math and nothing more.

So that’s another head scratcher…I used Jscan for tire size and gears and the speedometer doesn’t seem off. The more I’m thinking about it maybe I need to have gps running while I’m driving to see for sure if the Speedo is off but it seems pretty spot on.

 

[jadmt]

So I know pulling the diff is the sure fire way but was trying to avoid this seeing how I just put new gear oil in it (yeah I know that could be lazy of me I just figured there may be a less invasive option).

We did jack it up and spin it seemed like 2 tire rotations gave us about the 4.10.

I know it is a pain to count the shaft rotations but rotate the tire at least 5X while counting

 

[darnett]

I did the 392 axle swap and suspected I had 3:73 gears. You can pop the cover and count gears but I just spun the driveshaft and counted how many times it spins to one tire rotation. if its about 3 and 3/4 turns then your 3:73. if its closer to 4 then 4:10 etc. I programmed in 3:73 gears and my tire size and am within 1mph or so on the speedometer so thinking that was close enough

Sponsored