mikesas2

I'm a new owner of an '18 JK. I purchased it with some damage, but recently found that the driver side upper C is bent in. In looking at these front axles, I'm seeing aftermarket replacements that are listed as 2007-2018 in year. But when I look up factory replacement, or used replacement, it is showing a cut off around 2016. Is there a difference in say a 2008 and a 2018 JK? The 18 I have has 3.21's in it. I do have a 2008 with both complete 3.73's. The previous owner has already put at least a 3" lift under and it is running 35's. I haven't driven it yet, but I've heard grumblings of the 3.21 being sluggish with this kind of setup.

Also, I will update signature soon with all specs

Thanks

karls10jk

There was a minor change through the years on the ears of the yokes in the axle shafts but I don't see why you wouldn't be able to swap the axle without issue. They all use the same sensors. It's a good time to do c gussets and ball joints if you so choose. Also good time to freshen up the u-joints while you've got a little bit of time. Maybe pull the shafts from your current axle and use it in your 'new' axle.

jdinny

The housings are a bolt in swap from '07 to '18
The axle u-joint change started in late '12.
Sports and Sahara's got the Rubicon size axle yokes.
U-joints switched from 760X to 7166X
New style yokes, DANA SPICER 5-7166X
Utilizes inside "C" Clips to lock u-joint in place.
Dimension A = 2.405 inches
Dimension B = 2.405 inches
Dimension C = 1.188 inches ( 1 3/16 inches )
Dimension D = 1.188 inches ( 1 3/16 inches )


Early style SPICER 5-760X, note the difference in ring retainer groove.
Dimension A = 2.188 inches ( 2 3/16 inches )
Dimension B = 2.188 inches ( 2 3/16 inches )
Dimension C = 1.188 inches ( 1 3/16 inches )
Dimension D = 1.188 inches ( 1 3/16 inches )

The difference between the '08 and the '18, is the '08 would take a 760X front axle u-joint, and the '18 would use a 7166X. Externally, all is the same, internally, the older axle shaft had smaller yokes, using the 760X

karls10jk

Jdinny- that's good information. I knew their was a change but I didn't recall all of that. I guess I need to go check my spare axle shafts and see what u-joints are in them. I know I've got the 760's in my current shafts but that doesn't help much if I'm stocking parts for the other shafts.

Also with the yoke change. I believe they slimmed down the heads of the hub bolts too but I don't have old and new part numbers in front of me.

Sixty4x4

Also the earlier front axle tubes are larger outer diameter from early Rubicon to later. That comes from me measuring my sons 2016 Ruby axle to my 2008 Ruby with a Vernier caliper.

jdinny

That's right. I did forget about the bolt heads.

I knew/thought the Rubicon tubes were bigger, but I thought the tubes diameter might have been increased when they added the larger yokes.
Not so huh? Rubicons are still bigger?

mikesas2

***Update***

In looking the rig over some more, it has Teraflex covers front and rear. It still has a Dana 30 up front, but i did drain and pull the cover to see if it had been re-geared. And it has. It has 4.56's in it. So, I'm not seeing the need for the swap since it's not running the factory 3.21's.

Thanks for all the input. I have other JK's getting put together and the axle/u-joint change is great info.
Thanks