Sure it's Bigger... but is it actually Better? DISSECTING the JL WRANGLER Front Axle

wayoflife

Administrator
Staff member
Is there any issue with the transfer case or electronics caused by removing the FAD?

Yes and no. Once you remove the FAD, you will NEED something like a Tazer JL to turn it off in the computer. The FAD is tied into things like your sway bar disconnect and lockers and failure to do this will make it so that you can't use anything 4WD related.
 

wayoflife

Administrator
Staff member
I should note that initially, I had a problem even using my Tazer JL to turn things off but have since used their latest beta update and things are "better" now. Better in the sense that I now have my rear locker and can use my e-disco again but I still have a SERV 4WD and locker warning light on my dash. I'm hoping Z Automotive can help me out with this.
 

Jeeeep

Member
Here's a few shots of what the ProRock 44JL looks like installed.

20190205184021-05570732-me.jpg


20190205184031-349da2d5-me.jpg


20190204201916-19c2c27a.jpg

Is the PR44JL only available with RCV's?
 

Jeeeep

Member
seeing that weak point on the JL makes me want to delay putting on the 37's until I can plan an axle swap.

I'm not worried about it failing from wheeling, but everyday driving :doh:

I was going to put the Machete's w/ 37x13.50 Coopers on it but now I'm thinking the backspace would put additional stress on the weak point.

One thing to plan on hubs about every 6-months but don't really want to get stuck because of an axle failure that so far appears to be denied warranty.

Just looked up the price of a PR44JL on Quadratec- $2570 (includes shipping)

Will the stock internals fit the PR44JL?

Dynatrac, when are you going to have axle shafts?

dammit, I need to get a Magic 8-ball to get answers to all my questions :D
 

Saddletramp

Member
Eddie, one of the things I liked about the FAD idea was no turning front driveshaft, hence no highway speed vibes, what I loved about past 60's on my JK's with lockout hubs.

Any vibes and/or change with the PR44 JL housing and connected front driveline systems at highway speed???
 

wayoflife

Administrator
Staff member
Eddie, one of the things I liked about the FAD idea was no turning front driveshaft, hence no highway speed vibes, what I loved about past 60's on my JK's with lockout hubs.

Any vibes and/or change with the PR44 JL housing and connected front driveline systems at highway speed???

First off, vibration is a condition created from a drive shaft that isn't balanced. With a low 4.10 or lower gear ratio, you won't feel it or at least, not very much. When you get up into the 5.13 or 5.38 ratio, your drive shaft spins so much faster that an unbalanced shaft will start to reveal itself in the form of vibrations. Too much caster will only amplify this. In other words, you don't need hubs to fix this problem - you just need a well balanced shaft and with the correct amount of caster - typically, about +4°.

Second, ALL ProRock axles including the PR44JL come with +6° of caster built into it. This allows for a bit more adjustment room to help mitigate vibes and without having to compromise caster.
 

JIMBOX

New member
:D EASY my friend--

I think that the jeeps AXLE SPEED is dependent ONLY on VEHICLE/WHEEL SPEED--the DIFF. RATIO will increase the ENGINE/TRANNY TORQUE/RPM POWER to the axles, but----

The AXLES SPEED WILL ONLY RELATE their RPM to the WHEEL SPEED, which will relate to VEHICLE SPEED mainly in 2hi--

WHAT DO YOU THINK ???

:thumb: JIMBO !
 

wayoflife

Administrator
Staff member
:D EASY my friend--

I think that the jeeps AXLE SPEED is dependent ONLY on VEHICLE/WHEEL SPEED--the DIFF. RATIO will increase the ENGINE/TRANNY TORQUE/RPM POWER to the axles, but----

The AXLES SPEED WILL ONLY RELATE their RPM to the WHEEL SPEED, which will relate to VEHICLE SPEED mainly in 2hi--

WHAT DO YOU THINK ???

:thumb: JIMBO !

I apologize if I'm missing something but I'm not entirely sure I'm understanding what you're trying to get at. Just so that it isn't missed, we're talking about the front DRIVE SHAFT here. With the FAD, it will not spin at all UNLESS you've got 4WD engaged. However, without the FAD, the differential WILL cause it to spin. THIS is where the problem with vibrations occur. Are we on the same page now?
 

JTCO

Meme King
:D EASY my friend--

I think that the jeeps AXLE SPEED is dependent ONLY on VEHICLE/WHEEL SPEED--the DIFF. RATIO will increase the ENGINE/TRANNY TORQUE/RPM POWER to the axles, but----

The AXLES SPEED WILL ONLY RELATE their RPM to the WHEEL SPEED, which will relate to VEHICLE SPEED mainly in 2hi--

WHAT DO YOU THINK ???

:thumb: JIMBO !

b18c0d71997cd1ea0911c210319ce7ef1c518487e93bd8d78cda3fad5d72f73a.jpg

A 4.10 gear ratio will cause the drive shaft to spin about 4+ times for every front axle ring gear rotation.
A 5.38 gear ratio will cause the drive shaft to spin about 5+ times for every front axle ring gear rotation.
 

JIMBOX

New member
:D Heh Heh--YUP !

I was referring to PLAIN OL'/ UNEMCUMBERED AXLE SPEED/RPM and not even considering the FAD--
It seems so SAD that FCA/CHRYSLER made such a great MODERNIZED 2018 jeep AND totally screwed up the front axle/tubing !

Have a great day

:thumb: JIMBO
 

silverbullet88

New member
I should note that initially, I had a problem even using my Tazer JL to turn things off but have since used their latest beta update and things are "better" now. Better in the sense that I now have my rear locker and can use my e-disco again but I still have a SERV 4WD and locker warning light on my dash. I'm hoping Z Automotive can help me out with this.

I went with the ULtimate dana 44 w5.13’s for the JL. FAD is gone and the wall thickness is .375..so should be good to go. Also got it complete with 1410 U joint full cuticle clip shafts for under 4k shipped. Almost went PR44 though. Hopefully I don’t regret it!

Anyways I disabled the FAD with my tazer but now I have no dash indications that 4wd hi or low is functioning lol. It does though so it’s sort of strange. I have a basic sport dash/ 5” u connect.

Also, the synergy Tie rod and bracket are great! Here’s a few pictures comparing the 1350’s and 1410’s FD2F4152-F252-4209-A66D-85765D88AE4E.jpgCCE7F3DA-EC41-4D8D-9C8B-39C59BF24F0D.jpg2F76C1ED-12BC-4C1B-A89F-54E56A4F6FE1.jpg
 

wayoflife

Administrator
Staff member
Anyways I disabled the FAD with my tazer but now I have no dash indications that 4wd hi or low is functioning lol.

Z Automotive has a beta update that they released on 1/30/19. You'll need to download it from their site and then manually input it into their firmware update software. That should give you your dash indicators back.

On a side note, maybe I'm just seeing things but your front axle looks like it's got a CRAZY amount of caster.
 

silverbullet88

New member
Z Automotive has a beta update that they released on 1/30/19. You'll need to download it from their site and then manually input it into their firmware update software. That should give you your dash indicators back.

On a side note, maybe I'm just seeing things but your front axle looks like it's got a CRAZY amount of caster.

Cool thanks!

Oh yeah Dana took an idea from currie and rotated the center section 1/2" for more clearance
 

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