07 Auto JK Unlimted Towing/Gear change
01-25-2010, 04:38 PM
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07 Auto JK Unlimted Towing/Gear change
I have been searching online and I read the FAQ here:
https://www.jk-forum.com/forums/21127-post/
There is a ton of info on gear changes, but mostly its for offroading and large tires.
I have an AUTOMATIC 07 Unlimited X, with the factory tow package (4.10). Stock tires (32s I believe). My 4x4 needs end @ using sandy boat ramps, and I dont care about bigger tires.
I tow my jetski trailer ALOT, with 1000mile interstate trips a few times a year. The jetski trailer has (2) standup skis (300lbs each) and a dirtbike (250lbs). Trailer itself weights less then 650lbs. Totals about 1500lbs, well within the 3500lbs that the JK is supposesd to be able to tow. Problem is @ highway speed (70-75mph) I must have OD OFF, even on level pavement....Or else it will downshift like crazy, and the RPM's are over +3,100. It just seems like I have to run the jeep to hard for such a light load. My question is, would changing my gearing help my towing? I am willing to even down size my tires if that will help the towing performance. I know the jeep isnt supposed to be a towing maching, but I am not trying to pull a 6000lb enclosed toy hauler or heavy boat. A pickup doesnt really fit my lifestyle, I need the large enclosed cargo area the JK offers. I am starting to debate trading it in for a 5.7hemi grand cherokee for the improved towing performance, but I do love the JK otherwise.
Any advice is greatly appreciated!!!
https://www.jk-forum.com/forums/21127-post/
There is a ton of info on gear changes, but mostly its for offroading and large tires.
I have an AUTOMATIC 07 Unlimited X, with the factory tow package (4.10). Stock tires (32s I believe). My 4x4 needs end @ using sandy boat ramps, and I dont care about bigger tires.
I tow my jetski trailer ALOT, with 1000mile interstate trips a few times a year. The jetski trailer has (2) standup skis (300lbs each) and a dirtbike (250lbs). Trailer itself weights less then 650lbs. Totals about 1500lbs, well within the 3500lbs that the JK is supposesd to be able to tow. Problem is @ highway speed (70-75mph) I must have OD OFF, even on level pavement....Or else it will downshift like crazy, and the RPM's are over +3,100. It just seems like I have to run the jeep to hard for such a light load. My question is, would changing my gearing help my towing? I am willing to even down size my tires if that will help the towing performance. I know the jeep isnt supposed to be a towing maching, but I am not trying to pull a 6000lb enclosed toy hauler or heavy boat. A pickup doesnt really fit my lifestyle, I need the large enclosed cargo area the JK offers. I am starting to debate trading it in for a 5.7hemi grand cherokee for the improved towing performance, but I do love the JK otherwise.
Any advice is greatly appreciated!!!
01-25-2010, 04:44 PM
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01-25-2010, 05:41 PM
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Check the RPM chart in the Drivetrain FAQ's.
Yes, gearing lower will give better 'O/D On' towing ability. The downside is that towing in over-drive will heat up the transmission, which may cause more problems for you. You'll want a cooler, if you don't have one already.
Pretty much anywhere you look, the advice is to tow O/D off. You don't have a very heavy load, but any time the tranny downshifts out of overdrive (on hills or whatever), think about how high your rpm's will jump.
32's with 4.88's
O/D On - 2476 rpm @ 70
O/D Off - 3588 (ish) rpm @ 70
32's with 5.13's
O/D On - 2603 rpm @ 70
O/D Off - 3772 (ish) rpm @ 70
If you drop tire height, the rpm's will climb again.
Yes, gearing lower will give better 'O/D On' towing ability. The downside is that towing in over-drive will heat up the transmission, which may cause more problems for you. You'll want a cooler, if you don't have one already.
Pretty much anywhere you look, the advice is to tow O/D off. You don't have a very heavy load, but any time the tranny downshifts out of overdrive (on hills or whatever), think about how high your rpm's will jump.
32's with 4.88's
O/D On - 2476 rpm @ 70
O/D Off - 3588 (ish) rpm @ 70
32's with 5.13's
O/D On - 2603 rpm @ 70
O/D Off - 3772 (ish) rpm @ 70
If you drop tire height, the rpm's will climb again.
Last edited by nthinuf; 01-25-2010 at 05:44 PM.
01-25-2010, 05:58 PM
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Check the RPM chart in the Drivetrain FAQ's.
Yes, gearing lower will give better 'O/D On' towing ability. The downside is that towing in over-drive will heat up the transmission, which may cause more problems for you. You'll want a cooler, if you don't have one already.
Pretty much anywhere you look, the advice is to tow O/D off. You don't have a very heavy load, but any time the tranny downshifts out of overdrive (on hills or whatever), think about how high your rpm's will jump.
32's with 4.88's
O/D On - 2476 rpm @ 70
O/D Off - 3588 (ish) rpm @ 70
32's with 5.13's
O/D On - 2603 rpm @ 70
O/D Off - 3772 (ish) rpm @ 70
If you drop tire height, the rpm's will climb again.
Yes, gearing lower will give better 'O/D On' towing ability. The downside is that towing in over-drive will heat up the transmission, which may cause more problems for you. You'll want a cooler, if you don't have one already.
Pretty much anywhere you look, the advice is to tow O/D off. You don't have a very heavy load, but any time the tranny downshifts out of overdrive (on hills or whatever), think about how high your rpm's will jump.
32's with 4.88's
O/D On - 2476 rpm @ 70
O/D Off - 3588 (ish) rpm @ 70
32's with 5.13's
O/D On - 2603 rpm @ 70
O/D Off - 3772 (ish) rpm @ 70
If you drop tire height, the rpm's will climb again.
Last edited by shawn_nj; 01-25-2010 at 06:01 PM.
01-25-2010, 06:12 PM
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You might do a quick search for the recent Flashpaq threads. There has been some very good feedback on it so far. Don't expect hemi-power, of course, but may be something to look into until you can come up with the 20k for a hemi swap... 