Hi guys,
Need some experienced advise.
I just swapped out my front axle on my 2015 JKU with a D44 Rubi axle.
The front axle is now geared to 4.88.
The rear axle is still stock gear ration, I have an appointment to regear rear next week.
The front drive shaft is out of the jeep until after I get the rear heated to 4.88.
I tried to take my jeep around the block and it's now in limp mode.
Is this because the computer knows the front and rear gear rations are different?
Does it get this information from the abs sensors?
Much appreciate any help, I'm assuming it's in limp mode from either the front drive shaft being out of the jeep or it's seeing the tone rings are registering different readings from front to back?
Thanks in advance!

 

You did nothing program wise right, as the back is still factory. The ABS sensor up front is reading wheel speed, which has not changed due to the different gearing, and there is nothing that senses that the front DS is there or not. You haven't overlooked something ridiculous, like reinstalling the speed sensors after the axle swap right? Just covering all bases.

 

Nothing programmed yet, I double checked the connections to the sensors and also pulled them and cleaned them off but still having the same issues. Traction control, brake and abs lights are on and it's it's limp mode.
I just disconnected the battery in an attempt to reset the computer, not sure it's going to help but figure worth a try.

 

Sensors come with the axle or did you reuse your old ones?

 

Reused old sensors

 

Lol, your tone rings are reading different speeds due to the different gear ratios.

match the gear ratio asap

/thread

 

The front tires are not moving any different speed than the rear tires. The tires are driving the gears at this moment, not the other way around.

This set up should work, and has for many for years. It should work even with the DS installed (however removed is best just for safety) as long as 4WD is not activated. Something is wonky.....

 

It ended up being both front speed sensors, replaced them and jeeps fine now.
It's strange both were bad but it's fixed now.
Thanks to everyone fir responding!

 

Nah, you probably damaged them when you pulled them out. I cracked mine when I pulled them for the axle swap.

Fortunately, I wasn't reusing them, I replaced the unit bearings and they came with new wheel sensors.