Cutting and welding differential for caster

[JT Nate]

The JTs all come with a fad. The only difference is the shift fork is welded to the block off plate effectively locking out the disconnecting means. They literally removed none of the potential failure points aside from the shift motor. Even if you were worried about a shift motor failure you could carry the block off plate with welded shift fork in your tool bag. If the fad motor failed, 4 bolts and about 5 minutes you're back in business.

It sounds like I just need to get the motor and coupler (Ryanlsmith might be helping me out with those parts) Then wire it to an aux switch.

Sponsored

 

[Blade1668]

Warning thread derail... If a problem with O.P. I'll delete it.

The JTs all come with a fad. The only difference is the shift fork is welded to the block off plate effectively locking out the disconnecting means. They literally removed none of the potential failure points aside from the shift motor. Even if you were worried about a shift motor failure you could carry the block off plate with welded shift fork in your tool bag. If the fad motor failed, 4 bolts and about 5 minutes you're back in business.

On my JT I'm not really worried, I was just giving some of my past experiences with it. I wasn't trying be a all knowing in any way. I definitely don't have as much experience with the new FAD or even the late axles in Jeeps. Other than my JT my newest Jeep is a 05 TJ Unlimited, low pinion 30, and XJ's / MJ's with high pinion D30's with and without along with a CAD delete D30 high pinion. Most of my flogging of my Jeeps is past unless I happen to come into a windfall of $$$. I'm at a point I'd rather be just out driving than breaking parts anymore. I even downgraded my driveway some. 🫣 filling ruts and rocks in place with concrete.
My 4 wheelers can at least be trailered home and fixed cheaper. Heck my new 4 wheeler cost more than my Comanche did when brand new. I'm past the keeping up with the Jones. I figured that out in early 2000's, I have to many other expensive hobbies. Some I enjoy as much. If not for a bum foot, I'd likely be somewhere trying to get more bottom time scuba diving right now.
One of my primary reasons for my JT was my towing vehicle and a D.D. with reasonable fuel mileage. My Wrangler is great to to drive, but towing a trailer with it not as fun in some situations. It actually tows better than my JT in many ways.

 

[Zachanadandy]

It sounds like I just need to get the motor and coupler (Ryanlsmith might be helping me out with those parts) Then wire it to an aux switch.

Should be all you need. I'm not even sure the coupler is different with the factory block off. I know some aftermarket deletes use a line coupler that can't shift on and off and therefore their block off plates don't have the fork. To me it looks like all the factory did was take the same housing, shafts, and internal parts and replaced the moveable fork/motor assembly with a fixed fork cover?

 

[Zachanadandy]

Warning thread derail... If a problem with O.P. I'll delete it.


On my JT I'm not really worried, I was just giving some of my past experiences with it. I wasn't trying be a all knowing in any way. I definitely don't have as much experience with the new FAD or even the late axles in Jeeps. Other than my JT my newest Jeep is a 05 TJ Unlimited, low pinion 30, and XJ's / MJ's with high pinion D30's with and without along with a CAD delete D30 high pinion. Most of my flogging of my Jeeps is past unless I happen to come into a windfall of $$$. I'm at a point I'd rather be just out driving than breaking parts anymore. I even downgraded my driveway some. 🫣 filling ruts and rocks in place with concrete.
My 4 wheelers can at least be trailered home and fixed cheaper. Heck my new 4 wheeler cost more than my Comanche did when brand new. I'm past the keeping up with the Jones. I figured that out in early 2000's, I have to many other expensive hobbies. Some I enjoy as much. If not for a bum foot, I'd likely be somewhere trying to get more bottom time scuba diving right now.
One of my primary reasons for my JT was my towing vehicle and a D.D. with reasonable fuel mileage. My Wrangler is great to to drive, but towing a trailer with it not as fun in some situations. It actually tows better than my JT in many ways.

I agree that the old cad vacuum actuated setup was problematic. Had to pull it out and force the coupler into place with a screw driver on my old XJ. If the modern axle wasn't already built with the fad parts I wouldn't go out sourcing the 2 piece shaft, coupler, etc to add it. Being that is all there minus the motor it's the easy button to curing front drive shaft vibes in 2wd. I only drive the JT to the mall anyway.

 

[JT Nate]

Should be all you need. I'm not even sure the coupler is different with the factory block off. I know some aftermarket deletes use a line coupler that can't shift on and off and therefore their block off plates don't have the fork. To me it looks like all the factory did was take the same housing, shafts, and internal parts and replaced the moveable fork/motor assembly with a fixed fork cover?

That makes sense since RyanlSmith had a Fad delete installed. I should have the right coupler already. Thanks for clearing that up!

 

[OldButStillJeeping]

All this for a vibration at 60 mph?

>Take off your lift and get it aligned with stock susp and wheels / tires and drive it.

>If you wheel it hard, get a custom Dana 60 front axle with locking hubs. Spend the big boy $. Done.

>Adding a FAD???.... Is going backwards. 100 %. That FAD is just another break or fail point. POS.

Next year I will dump my FAD on my JTM and solidify it.

Good luck.

 

[CrazyCooter]

Is going back to the OE front driveline not a possibility?

 

[Zachanadandy]

All this for a vibration at 60 mph?

>Take off your lift and get it aligned with stock susp and wheels / tires and drive it.

>If you wheel it hard, get a custom Dana 60 front axle with locking hubs. Spend the big boy $. Done.

>Adding a FAD???.... Is going backwards. 100 %. That FAD is just another break or fail point. POS.

Next year I will dump my FAD on my JTM and solidify it.

Good luck.

There are tens of thousands of lifted JLs/JTs on the road and trails and 95% of those still have the FAD. The 2024 and up models still have the FAD it is just locked into position. The only fail point I've seen is the cast FAD housing which they all still have and even that is a very rare occurrence. The 2 piece shaft is probably weaker than a single piece, but again they all still have it and I haven't seen a single failure. Now we all need 60s with hubs just to wheel? Remove the lift and run stock tires? Or just make the FAD you already have functional for a couple hundred dollars and go wheeling? When you say drop the FAD and solidify it are you just talking the axle shaft? The failures seem to be the housing so unless you are swapping the front axle for an aftermarket you aren't gaining much.

 

[JT Nate]

I agree that the old cad

All this for a vibration at 60 mph?

>Take off your lift and get it aligned with stock susp and wheels / tires and drive it.

>If you wheel it hard, get a custom Dana 60 front axle with locking hubs. Spend the big boy $. Done.

>Adding a FAD???.... Is going backwards. 100 %. That FAD is just another break or fail point. POS.

Next year I will dump my FAD on my JTM and solidify it.

Good luck.

slight vibration…. But I want things perfect. Not removing the lift as that would take my daily driver out for 2 days as well as I sold the stock rubicon arms/ parts. I get the FAD is a weak point but it already has the fad axles and everything else that comes along with it minus the actuator. So there is no difference. Love the way it wheels with the 3.5 lift and 38’s and 5.13’s. Totally worth it. Just dialing it in. Yes the plan down the road is gonna be a 392 and Dana 60’s. With hydraulic steering but that’s all 5 yrs down the road. Solid advice though

There are tens of thousands of lifted JLs/JTs on the road and trails and 95% of those still have the FAD. The 2024 and up models still have the FAD it is just locked into position. The only fail point I've seen is the cast FAD housing which they all still have and even that is a very rare occurrence. The 2 piece shaft is probably weaker than a single piece, but again they all still have it and I haven't seen a single failure. Now we all need 60s with hubs just to wheel? Remove the lift and run stock tires? Or just make the FAD you already have functional for a couple hundred dollars and go wheeling? When you say drop the FAD and solidify it are you just talking the axle shaft? The failures seem to be the housing so unless you are swapping the front axle for an aftermarket you aren't gaining much.

exactly. Sorry responded before seeing your response that says it all

 

[JT Nate]

Is going back to the OE front driveline not a possibility?

The stock rezeppa driveshaft doesn’t have a slip and would not work with the lift and articulation.

 

[Stan H]

There are tens of thousands of lifted JLs/JTs on the road and trails and 95% of those still have the FAD. The 2024 and up models still have the FAD it is just locked into position. The only fail point I've seen is the cast FAD housing which they all still have and even that is a very rare occurrence. The 2 piece shaft is probably weaker than a single piece, but again they all still have it and I haven't seen a single failure. Now we all need 60s with hubs just to wheel? Remove the lift and run stock tires? Or just make the FAD you already have functional for a couple hundred dollars and go wheeling? When you say drop the FAD and solidify it are you just talking the axle shaft? The failures seem to be the housing so unless you are swapping the front axle for an aftermarket you aren't gaining much.

Has anyone answered the question as to why the FAD motor was removed ?

 

[Zachanadandy]

Has anyone answered the question as to why the FAD motor was removed ?

I think with the relaxed café standards/removed fines they saw an easy way to save a few dollars on the build side between wiring and the electric motor so they ditched it, but that's speculation. Obviously all the weak points are still there so it wasn't for strength or reliability. I've been on the JL forum since we bought our 2019 in early 2019, and haven't seen a single post of a motor failure. For stock height it's not needed and if the fractional mpg gain isn't necessary why bother if you're Jeep? Conversely if you're lifted and want to run decent caster is almost mandatory once you're beyond the limits of the rzeppa factory front shaft.

 

[Supazuk]

I'm reading lots of bad info here and on the other thread
I have build many rigs from ground up and did alignment in an off road shop
I have 3" of lift on my gladiator caster at 6* and a lunch box locker (driveshaft spins) Zero vibrations


A. Optimum caster is 6* (weight bias and level of vehicle can change this)

B. Drive shaft angle (Front or rear) at T-case and pinion should be the same angle Unless you have a Dual Cardan shaft then the pinion should point to the T-case resulting in zero reference angle to the driveshaft

C. A vibration from the driveshaft spinning is a result of being out of phase or poorly balanced


tom woods info (one of the best)
angles
https://4xshaft.com/blogs/general-t...le-cardan-drive-shafts-for-your-jeep-or-truck
vibrations
https://4xshaft.com/blogs/general-tech-info-articles/diagnosing-drive-shaft-vibrations
in phase
https://4xshaft.com/blogs/faq/driveshaft-in-phase

 

[Stan H]

I think with the relaxed café standards/removed fines they saw an easy way to save a few dollars on the build side between wiring and the electric motor so they ditched it, but that's speculation. Obviously all the weak points are still there so it wasn't for strength or reliability. I've been on the JL forum since we bought our 2019 in early 2019, and haven't seen a single post of a motor failure. For stock height it's not needed and if the fractional mpg gain isn't necessary why bother if you're Jeep? Conversely if you're lifted and want to run decent caster is almost mandatory once you're beyond the limits of the rzeppa factory front shaft.

So the wiring is gone also ?
I still dont understand the OP's problem.
So if it was eliminated from the wiring harness then it really was stupid
What if someone wanted a FAD again?

 

[CrazyCooter]

The stock rezeppa driveshaft doesn’t have a slip and would not work with the lift and articulation.

Wouldn't it be worth losing a tiny bit of droop travel to make this issue go away? What length front shocks are you running?

Sponsored