Lock out hubs/front driveshaft install.

[Rick Shols]

Hello! I have a 2021 Sport with manual trans, 3.6 gas. I tow a cargo trailer convert that is 3300 Lbs, ready to go. Or at least enough for the first week! Soon after purchase I regeared the Jeep to 4:56. It has stock diameter tires. I replaced them with some an inch wider, not taller. This combo is great on the road pulling at 65MPH most times.

When I need to set up or store the trailer is when the problem starts. The reverse gear is too high even with the 4:56's. Slipping the already questionable clutch concerns me.

So, I would like to use the low case to back the trailer without the front axle involved. Two things I can think of to do. Install manual hub lock outs or a front driveshaft disconnect. I'm leaning towards the disconnect.

Finally, the question! Does anyone know who could provide the locks outs or the disconnect?

I've searched the forum and found one thread that within a page or two devolved into opinion. I did not see a source mentioned.

Thanks!

Rick

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[Zachanadandy]

There are no hub kits for the JL/JT axles and I've never seen a drive shaft disconnect offered either. I'd just wire your fad to a switch so you could turn it off.

 

[Rick Shols]

Thanks for your reply! You've saved me a lot of money, frustration and time! Yesterday I din't know I had a FAD. Now I've had a look and have found it! I am going by the dealership to do some research on the wiring. I am imagining that there is a switch somewhere around the lever that would give access to the control wiring. Thanks again.

 

[rharr]

i believe you can use the jscan app and do a manual override that disconnects the FAD when in 4x4.

I haven't tested it but all you would need to do is put the jeep in 4L and jack the front up, disconnect the fad through jscan and see if the front wheels spin freely.

 

[LouisvEarlleJT]

When I need to set up or store the trailer is when the problem starts. The reverse gear is too high even with the 4:56's. Slipping the already questionable clutch concerns me.

Is there a reason you put dump truck gears in but didn't go for bigger tires? I know you said you put wider ones on, but they're still going to want to spin up much faster now with those gears. Seems like a lot of hassle to figure out a work around when maybe just going to some skinny 35's or something would do the trick.

 

[Zachanadandy]

Is there a reason you put dump truck gears in but didn't go for bigger tires? I know you said you put wider ones on, but they're still going to want to spin up much faster now with those gears. Seems like a lot of hassle to figure out a work around when maybe just going to some skinny 35's or something would do the trick.

4.56s are hardly dump truck gears and his complaint is not that is geared too low but that is geared too high in reverse. Fought the same battle in the sand with the 2.0t and the auto in our jlur. Even on 38s it was fine even taking off in deep sand with the factory 4.10s. In order to back up you'd have to put it in 4LO, which was then way too low with the 4-1 rubicon tcase. Why the reverse gear would be taller than 1st gear is beyond me.

 

[LouisvEarlleJT]

4.56s are hardly dump truck gears and his complaint is not that is geared too low but that is geared too high in reverse. Fought the same battle in the sand with the 2.0t and the auto in our jlur. Even on 38s it was fine even taking off in deep sand with the factory 4.10s. In order to back up you'd have to put it in 4LO, which was then way too low with the 4-1 rubicon tcase. Why the reverse gear would be taller than 1st gear is beyond me.

I just used that because they’re fairly typical on single axle dumps (like a f-450, etc).

Just saying that if it was bad before the regear it’s gotta be WORSE after. A larger tire would help.

 

[Zachanadandy]

I just used that because they’re fairly typical on single axle dumps (like a f-450, etc).

Just saying that if it was bad before the regear it’s gotta be WORSE after. A larger tire would help.

The reverse gear is too high, the regear helps that. Larger tires would make it worse. Again, why anyone would want a reverse gear that's taller than 1st gear is beyond me. You're starting from a dead stop in either gear and I think reversing is typically even slower acceleration than going forward.

 

[Rick Shols]

Hello. Louis let me fill this in. The factory 3:73's made the Jeep nearly unusable when pulling the trailer. That is unless you like holding it in 2nd up to the higher registers to pull even the average hill here in WNC. This is not a race car and I am an old retired guy thats not interested in going down the freeway 90Mph! The regear made the Jeep useful, actually get to use 6th on the highway when not towing! I tow in 4th/5th and keep it in the right lane @ about 65. It tachs about 2300 @ 70 plus a little in 6th and has at least some throttle response. I may have lost a small bit of mileage, I have gained much more in the usable dept. Towing I average 13/14 Mpg in a neutral/light wind, just running around 19/20. I have averaged 22 on a long, non towing trip on the I state. I run about 73 on the cruise. The issue I am looking to resolve is the already mentioned too high reverse gear when backing said trailer. Darn hard to do without slipping the clutch which I believe is a really bad idea. Hope this clears things up.

 

[Rick Shols]

Hi Rharr, thanks for the tip! That said I didn't understand much of it, my fault. I unfortunately fall into the "let the grandkids fix your phone" category!

 

[rharr]

no worries, unfortunately all these new vehicles are more computer then hardware. Gone are the days manual knobs and switches.

Take some time and try to research the Jscan app, it's a android phone based program that lets you interact directly with the computer controls of the jeep. The FAD being one of them.

 

[Rick Shols]

Thanks, I'll try! Will it fulfill this scenario? Pulling into campground all systems normal. Find your lot, disable the FAD relatively quickly and crawl in in reverse? If it will do that I would be very interested.

 

[rharr]

It should, with the fad un locked then you cant transfer power to either wheel. The front drive shaft will spin the front carrier spider gears and with out a way to send power to tires cause the passangeer axle is unlocked , the inner shaft just spins. Its really no different then the one wheel spin on ice, the tire with no traction gets the power, in this case the the unlocked shaft gets all the power cause there is no traction to send it to.

I just checked the app, if you go to module tab, drive train control, configuration, FAD enabled -yes/no, that should force a manual override.

But you won't know till you try it.

Normal operation, when you go to 4x4 mode high or low, it locks the FAD to engage the front axle, if you ever had the pleasure of a 1980s s-10 xyz 4x4, same setup, just used vacuum lines to engage the front axle, plenty of times it said I was in 4x4 but front wasn't engaged cause the vacuum system sucked.

 

[Rick Shols]

Or I suppose I could disable the FAD and make the road trip, reactivate after I unhook. You've got me thinking....

 

[rharr]

Or I suppose I could disable the FAD and make the road trip, reactivate after I unhook. You've got me thinking....

Fad isn't engaged in 2wd.

UNLESS you are running one of those full time 4x4 transfer cases, then good luck.

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