Regearing factory LSD
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JK Newbie
Joined: Sep 2018
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From: Lovell, WY
Regearing factory LSD
I currently have a 2013 JKU with factory LSD and 3.73 gears. Can I do a gear change to 4.88 without messing up the LSD? I've been told it isn't possible for some reason or another. Anyone done it?
JK Jedi Master
Joined: Jan 2008
Posts: 11,463
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From: Austin <--> Colorado Springs
What specifically was said?
The rear D44 carrier/limited should be fine with the either ratio. One problem that has been noted is that on newer JK's, you must update the computer to the new ratio!! (AEV ProCal, Superchips Flashcal / flashpaq, etc, etc) It's not a problem with the limited slip or the ratio itself, just a problem with the computer interpreting the data.
Another point of ongoing confusion is about 'automatic' lockers being run in newer Auto JK's. As far as I am aware, this does not apply to limited slips or selectable lockers, only auto-lockers like the Detroit Locker being run in the rear axles of 2012+ JK with auto transmissions. Depending on what was said, they could be confusing the performance of your factory limited slip with an auto-locker.
And another thing you could be hearing is about the carrier break on front D30's, which is between the 3.21 and 3.73 ratios. So a JK with 3.21's would need a new carrier (or locker, or full case limited) in that front axle when moving to 4.88's. Since you are starting with 3.73, not an issue.
I suppose one other thing you could be hearing is about the factory limited using clutches, which tend to wear out over time and become just another open carrier. If this is a concern for you, look at upgrading to Detroit Truetrac limited slips instead. Much better traction devices.
The rear D44 carrier/limited should be fine with the either ratio. One problem that has been noted is that on newer JK's, you must update the computer to the new ratio!! (AEV ProCal, Superchips Flashcal / flashpaq, etc, etc) It's not a problem with the limited slip or the ratio itself, just a problem with the computer interpreting the data.
Another point of ongoing confusion is about 'automatic' lockers being run in newer Auto JK's. As far as I am aware, this does not apply to limited slips or selectable lockers, only auto-lockers like the Detroit Locker being run in the rear axles of 2012+ JK with auto transmissions. Depending on what was said, they could be confusing the performance of your factory limited slip with an auto-locker.
And another thing you could be hearing is about the carrier break on front D30's, which is between the 3.21 and 3.73 ratios. So a JK with 3.21's would need a new carrier (or locker, or full case limited) in that front axle when moving to 4.88's. Since you are starting with 3.73, not an issue.
I suppose one other thing you could be hearing is about the factory limited using clutches, which tend to wear out over time and become just another open carrier. If this is a concern for you, look at upgrading to Detroit Truetrac limited slips instead. Much better traction devices.
Last edited by nthinuf; Dec 26, 2018 at 04:05 PM.
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Joined: Jan 2014
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From: SE Pa. W. Chester County
What specifically was said?
The rear D44 carrier/limited should be fine with the either ratio. One problem that has been noted is that on newer JK's, you must update the computer to the new ratio!! (AEV ProCal, Superchips Flashcal / flashpaq, etc, etc) It's not a problem with the limited slip or the ratio itself, just a problem with the computer interpreting the data.
Another point of ongoing confusion is about 'automatic' lockers being run in newer Auto JK's. As far as I am aware, this does not apply to limited slips or selectable lockers, only auto-lockers like the Detroit Locker being run in the rear axles of 2012+ JK with auto transmissions. Depending on what was said, they could be confusing the performance of your factory limited slip with an auto-locker.
And another thing you could be hearing is about the carrier break on front D30's, which is between the 3.21 and 3.73 ratios. So a JK with 3.21's would need a new carrier (or locker, or full case limited) in that front axle when moving to 4.88's. Since you are starting with 3.73, not an issue.
I suppose one other thing you could be hearing is about the factory limited using clutches, which tend to wear out over time and become just another open carrier. If this is a concern for you, look at upgrading to Detroit Truetrac limited slips instead. Much better traction devices.
The rear D44 carrier/limited should be fine with the either ratio. One problem that has been noted is that on newer JK's, you must update the computer to the new ratio!! (AEV ProCal, Superchips Flashcal / flashpaq, etc, etc) It's not a problem with the limited slip or the ratio itself, just a problem with the computer interpreting the data.
Another point of ongoing confusion is about 'automatic' lockers being run in newer Auto JK's. As far as I am aware, this does not apply to limited slips or selectable lockers, only auto-lockers like the Detroit Locker being run in the rear axles of 2012+ JK with auto transmissions. Depending on what was said, they could be confusing the performance of your factory limited slip with an auto-locker.
And another thing you could be hearing is about the carrier break on front D30's, which is between the 3.21 and 3.73 ratios. So a JK with 3.21's would need a new carrier (or locker, or full case limited) in that front axle when moving to 4.88's. Since you are starting with 3.73, not an issue.
I suppose one other thing you could be hearing is about the factory limited using clutches, which tend to wear out over time and become just another open carrier. If this is a concern for you, look at upgrading to Detroit Truetrac limited slips instead. Much better traction devices.