JK Questions And Answers

[rholbrook]

Looking at getting a jeep again and have a few questions.

When you order one, an option is the Towing Package. Does anyone know if that includes a trans cooler? The option is $495 and says to include a Class II hitch and 4 pin connector. Seems like a lot for a hitch and wiring harness. I may opt to not order the tow package and just get an aftermarket rear bumper instead. Any thoughts on why I would want to get the trailer tow package? I dont see myself hauling anything more than a small trailer with maybe three or four bikes on it.

Can a aftermarket controller change the locker selection on a Rubicon to lock the front axle first?

Is there any options that you think I shouldn't live without?

 

[TurboMinivan]

When you order one, an option is the Towing Package. Does anyone know if that includes a trans cooler?

It does not. Why? Because every Pentastar JK with the 5-spd automatic already includes a (large) trans fluid cooler as standard equipment.

The option is $495 and says to include a Class II hitch and 4 pin connector. Seems like a lot for a hitch and wiring harness.

For the record the Max Tow Package (available on the 4-dr) also includes the 3.73 axle ratio upgrade.

Any thoughts on why I would want to get the trailer tow package?

Umm... so you can tow a trailer?

Are you looking at a 2dr or 4dr JK?

 

[rholbrook]

It does not. Why? Because every Pentastar JK with the 5-spd automatic already includes a (large) trans fluid cooler as standard equipment.
Thank You



For the record the Max Tow Package (available on the 4-dr) also includes the 3.73 axle ratio upgrade.
I would opt for the 4.10 anyway

I would make sure the rear aftermarket bumper I get includes a hitch built in.
Umm... so you can tow a trailer?

Are you looking at a 2dr or 4dr JK?

4 Door Rubicon

 

[frieed]

Unless they've changed it since 2012, the front and rear lockers are independent.

 

[rholbrook]

Unless they've changed it since 2012, the front and rear lockers are independent.

When you select the LOCKER button, the first locker it engages is the rear, you press the button again and it engages the front.

 

[frieed]

D'oh
forgot about that part..

 

[mbryson]

4 Door Rubicon

I think (and Dempsey will confirm) that the "standard" Rubicon gets the 3.73 gears now? You can order 4.10 gears (and I would do that if I was going to stick to a "normal" 35" or slightly smaller tire).

 

[Greg]

I have a brand new JK receiver hitch w/ hardware and flat 4 trailer wiring harness... I bought the from Quadratec and they were back ordered, then found a used setup on craigslist and put it on. When I went to cancel the order, Quadratec shipped it out anyway.

I paid $90 for everything... yours for $75?

 

[rholbrook]

I think (and Dempsey will confirm) that the "standard" Rubicon gets the 3.73 gears now? You can order 4.10 gears (and I would do that if I was going to stick to a "normal" 35" or slightly smaller tire).

My plans were to stick with 35s and order the 4.10s

I have a brand new JK receiver hitch w/ hardware and flat 4 trailer wiring harness... I bought the from Quadratec and they were back ordered, then found a used setup on craigslist and put it on. When I went to cancel the order, Quadratec shipped it out anyway.

I paid $90 for everything... yours for $75?

I know that aftermarket bumpers may have a hitch built in but they are not as strong as one mounted directly to the frame. Can you text me a picture of what you have? I think you have my number, if not. 801-two zero one-589one

 

[Greg]

My plans were to stick with 35s and order the 4.10s

That's what I'm running and for normal driving, it's fine... towing on the other hand, it could use more gearing in the mountains. I towed my small trailer and 990 Adventure this Summer and it worked the V6 (and transmission) pretty hard.

I know that aftermarket bumpers may have a hitch built in but they are not as strong as one mounted directly to the frame. Can you text me a picture of what you have? I think you have my number, if not. 801-two zero one-589one

The hitch for the JK is tiny, I was surprised at how small it it... kinda spooky, IMO. It's probably easier for me to just post links to what I have... the shop is cold and locked up. This is what I have and what a JK with a tow package would come with...

http://www.quadratec.com/products/12015_1000_07.htm

http://www.quadratec.com/products/92015_8001_14.htm

 

[TurboMinivan]

I think (and Dempsey will confirm) that the "standard" Rubicon gets the 3.73 gears now? You can order 4.10 gears (and I would do that if I was going to stick to a "normal" 35" or slightly smaller tire).

This is correct. While the Rubicon 6-speed comes only with 4.10 gears, the Rubicon automatic comes standard with 3.73s and can optionally be upgraded to 4.10s.

That's what I'm running and for normal driving, it's fine... towing on the other hand, it could use more gearing in the mountains. I towed my small trailer and 990 Adventure this Summer and it worked the V6 (and transmission) pretty hard.

If you're gonna install 35" tires and then tow regularly, I agree with Greg: a gear upgrade (such as to 4.56) would be worthwhile.

The hitch for the JK is tiny, I was surprised at how small it it... kinda spooky, IMO.

That's because you're used to seeing typical hitches which must also include their own crossmember. Crawl under a full-size pickup that has no hitch, and look where one would go. What do you see there? Nothing. This is why you can't just throw some spindly little piece of steel under there; you need something stout to connect to the frame rails.

Now crawl under a JK that has no tow package and look where the hitch would go. What do you see? A frame crossmember. The strength and support is already there; all we need to do is bolt on the hitch attachment itself. It's not like we're just bolting it to the plastic bumper skin.

 

[Hickey]

On the locker issue, I can't speak to which programmer can control lockers independently. You should be aware that programmers are limited for the 15-16 models for now. They ECM has been a hard one to hack for the programming companies. I know most programmers require either an ECM from a 14 model be purchased, or you have to ship your new ECM to the tuner company, or swap them for one already programmed.

The AEV procal and Superchips FlashCal both work with the new models without ECM fudgery, but they are only meant to change speedo settings, tpms settings, and a few other minor things. They both run under $150.
There is a way to tap the wiring at the solenoids to activate the lockers independently. You're basically grounding the signal wire.

I've owned 14 Jeeps now, and that spiderweb shade is mandatory from now on. Love that sucker!

The 130 430 and 730 are the 3 stereo offerings. If you want nav, get the 430. If not, get the 130. The 730 is a lot more money for nothing special.

There was a significant change in the sound system in 15. Subwoofer was moved to the rear floor storage area, component speakers come standard, and a few more neat things.

Get the True Car app on your phone, enter all the options you want, then order it through Dempsey. He's a great guy to work with. I don't know how Dempsey feels about True car, but it virtually eliminated the haggling for me.

 

[TurboMinivan]

PM received. I'll respond tomorrow from the office.

 

[zmotorsports]

That's what I'm running and for normal driving, it's fine... towing on the other hand, it could use more gearing in the mountains. I towed my small trailer and 990 Adventure this Summer and it worked the V6 (and transmission) pretty hard.

My plans were to stick with 35s and order the 4.10s

Too bad you can't special order it with 4.56's or 4.88's. Those seem to be much better choices for 35" tires. I have one guy that I did 4.56:1 gears and his is really happy with them and does not tow anything.

Another guy I did 4.88:1 gearing because he has a small Tab camp trailer that he drags around. He is quite pleased. Both had 4.10:1 gearing from the factory.

Mike.

 

[mbryson]

Too bad you can't special order it with 4.56's or 4.88's. Those seem to be much better choices for 35" tires. I have one guy that I did 4.56:1 gears and his is really happy with them and does not tow anything.

Another guy I did 4.88:1 gearing because he has a small Tab camp trailer that he drags around. He is quite pleased. Both had 4.10:1 gearing from the factory.

Mike.

My opinion would follow that logic. 4.88 is a bit much for just driving around (for me). I have only towed my car hauler trailer back/forth from Woods Cross/Logan but the gear was appreciated for that. I have NO ISSUE climbing hills towing or otherwise.

 

[lhracing]

Before doing a regear I would order the Rubicon with 4.10 and drive it. The OD ratio on the automatic is .83 which with 35's and 4.10 gears at 70mph puts you at about 2290 rpm, 4.88's put you at about 2725. In my case which is very different from the Jeep that you are looking at (2008 with 6 speed, OD ratio .84) when I went to 4.88's my mileage dropped from about 16-18 to 12-13 mpg because of winding the motor higher. Even with the Pentastar engine the JK will never be a great tow vehicle, fine for short pulls with a small trailer but other than that you need a bigger truck.

As for the Lockers, I very seldom use the front locker, the rear being locked does fine most of the time and it is easier to steer.

 

[Greg]

Too bad you can't special order it with 4.56's or 4.88's. Those seem to be much better choices for 35" tires. I have one guy that I did 4.56:1 gears and his is really happy with them and does not tow anything.

Another guy I did 4.88:1 gearing because he has a small Tab camp trailer that he drags around. He is quite pleased. Both had 4.10:1 gearing from the factory.

Mike.

That would be nice, if the Rubicon had gearing option for 4.10, 4.56 and 4.88s! I could use more gearing, but it's hard to justify the cost of (IMO) going from 4.10's to 4.56's. For me, I think 4.88's would be too deep... I rarely tow and the 4.10's seem... sufficient?

My opinion would follow that logic. 4.88 is a bit much for just driving around (for me). I have only towed my car hauler trailer back/forth from Woods Cross/Logan but the gear was appreciated for that. I have NO ISSUE climbing hills towing or otherwise.

 

[mbryson]

Before doing a regear I would order the Rubicon with 4.10 and drive it. The OD ratio on the automatic is .83 which with 35's and 4.10 gears at 70mph puts you at about 2290 rpm, 4.88's put you at about 2725. In my case which is very different from the Jeep that you are looking at (2008 with 6 speed, OD ratio .84) when I went to 4.88's my mileage dropped from about 16-18 to 12-13 mpg because of winding the motor higher. Even with the Pentastar engine the JK will never be a great tow vehicle, fine for short pulls with a small trailer but other than that you need a bigger truck.

As for the Lockers, I very seldom use the front locker, the rear being locked does fine most of the time and it is easier to steer.

Wise words re: gearing here. I drove the JKU to Vegas and back a while ago. I get about 15-16 mpg at 70-75. When I buzz the motor to reach aerodynamically challenged speeds of 80-85, I drop to 11-12 mpg. I'd assume part of that is gearing vs RPM and the other part of that is driving a literal brick through the wind. If I geared another 3.6, I'd go with 4.56. If I had bought a 4.10 Rubicon, I'd leave it for the same reasons Greg mentioned.

i also bought a Sport and added lockers to avoid the factory telling me which lockers I had to engage and when. (That also brings up the D44 vs D30 debate. I don't think the ring/pinion is the weak point in either axle but the housing is the problem)). There are times I want a locked front and open rear and I can do that with how my Jeep is setup. I assume you can do that with the Rubicon, but didn't want to mess with "fixing" the OEM harness. The are fairly complex nowadays, even on a Sport and especially on a Rubicon with all the "necessary " options...

 

[Hickey]

I think 4.30's would be ideal with 35's and the Rubi t-case. Without the 4:1 case, I would be tempted to go 4.88.

 

[dbach]

changing just one ratio you wont tell much difference[ 4:10 to 4:56] I had 3:73 and changed to 4:56 what a difference !