HELP! Jeep jk front axle problem
11-13-2018, 03:43 PM
#1
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HELP! Jeep jk front axle problem
hey need help guys. So I picked up a 2015 wrangler jk sport with front axle assembly damaged and steering box damaged. so i bought the whole axle assembly, steeringbox and all the arms and changed everything now jeep runs fine but when i put into 4wd, the tires get locked and start dragging. Dont know if it’s alignment issue or what. But i was told its same axle assembly which is dana 30 with 3.21 gear ratio. But the part number doesn’t match with the original one that came off of jeep.
11-13-2018, 04:05 PM
#2
JK Jedi Master
First thing to do is verify both axles are of the same gear ratio.
Chock both tires on one side, and jack both tires off the ground on the other side, and support with jack stands.
Put the transmission in neutral.
On the side that's off the ground, put a chalk mark on each tire and each drive shaft.
Turn the front tire 2 complete revolutions while counting the drive shaft turns.
The number of drive shaft turns will be the gear ratio.
Repeat for the rear tire.
A little less than 3¼ turns is 3.21 gears.
A little less than 3¾ turns is 3.73 gears.
A little more than 4 turns is 4.10 gears.
Chock both tires on one side, and jack both tires off the ground on the other side, and support with jack stands.
Put the transmission in neutral.
On the side that's off the ground, put a chalk mark on each tire and each drive shaft.
Turn the front tire 2 complete revolutions while counting the drive shaft turns.
The number of drive shaft turns will be the gear ratio.
Repeat for the rear tire.
A little less than 3¼ turns is 3.21 gears.
A little less than 3¾ turns is 3.73 gears.
A little more than 4 turns is 4.10 gears.
11-13-2018, 04:54 PM
#3
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First thing to do is verify both axles are of the same gear ratio.
Chock both tires on one side, and jack both tires off the ground on the other side, and support with jack stands.
Put the transmission in neutral.
On the side that's off the ground, put a chalk mark on each tire and each drive shaft.
Turn the front tire 2 complete revolutions while counting the drive shaft turns.
The number of drive shaft turns will be the gear ratio.
Repeat for the rear tire.
A little less than 3¼ turns is 3.21 gears.
A little less than 3¾ turns is 3.73 gears.
A little more than 4 turns is 4.10 gears.
Chock both tires on one side, and jack both tires off the ground on the other side, and support with jack stands.
Put the transmission in neutral.
On the side that's off the ground, put a chalk mark on each tire and each drive shaft.
Turn the front tire 2 complete revolutions while counting the drive shaft turns.
The number of drive shaft turns will be the gear ratio.
Repeat for the rear tire.
A little less than 3¼ turns is 3.21 gears.
A little less than 3¾ turns is 3.73 gears.
A little more than 4 turns is 4.10 gears.
11-13-2018, 05:13 PM
#4
JK Jedi Master
If they are different...case closed.
If they are the same...more questions and details are in order.
11-14-2018, 06:30 AM
#5
JK Jedi
Totally agree with Ronjenx here. 1) the gearing in the diff seems ok by itself as it works in 2WD (everything is still rotating around while you're driving in 2WD, it's just not connected at the TC). 2) you put it in 4WD and doesn't work. This would seem to imply the front and rear gears are not matching. I suspect you've been smart enough to notice this problem quickly and haven't forced it too bad. So, rear gearing is trying to push you forward, front gearing doesn't match so gets locked up, hence tires won't move and the rear just keeps on trying to push.
I'd bet dollars to donuts gears don't match. If the front axle you bought was new, it's probably more likely someone regeard that jeep previously, and that the rear gearing is no longer factory. That seems more likely than you got something other than 3.21 gears in the new front axle.
I'd bet dollars to donuts gears don't match. If the front axle you bought was new, it's probably more likely someone regeard that jeep previously, and that the rear gearing is no longer factory. That seems more likely than you got something other than 3.21 gears in the new front axle.
11-17-2018, 08:50 AM
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First thing to do is verify both axles are of the same gear ratio.
Chock both tires on one side, and jack both tires off the ground on the other side, and support with jack stands.
Put the transmission in neutral.
On the side that's off the ground, put a chalk mark on each tire and each drive shaft.
Turn the front tire 2 complete revolutions while counting the drive shaft turns.
The number of drive shaft turns will be the gear ratio.
Repeat for the rear tire.
A little less than 3¼ turns is 3.21 gears.
A little less than 3¾ turns is 3.73 gears.
A little more than 4 turns is 4.10 gears.
Chock both tires on one side, and jack both tires off the ground on the other side, and support with jack stands.
Put the transmission in neutral.
On the side that's off the ground, put a chalk mark on each tire and each drive shaft.
Turn the front tire 2 complete revolutions while counting the drive shaft turns.
The number of drive shaft turns will be the gear ratio.
Repeat for the rear tire.
A little less than 3¼ turns is 3.21 gears.
A little less than 3¾ turns is 3.73 gears.
A little more than 4 turns is 4.10 gears.
Last edited by Ed89; 11-17-2018 at 08:56 AM.