Mileage Master
I drive 100 miles a day to and from work. I'm trying to find that happy medium between traction and mileage. My jeep is a "Willys Edition" X model with the 3.07 axle gears. With the modifications I've done, I get about 23 mpg.
I'm looking for some tires that will last a while and give good traction, but that won't hurt my mileage. Any ideas would be helpful.Jim KayneVia e-mail
That's really good mileage. Better than I ever got with my four-cyl. YJ on P225/75R15 tires. For your criteria of good mileage, long wear, and good traction, you're going to want to stick with the stock tire size. With the 3.07 gears, bumping tire size up even just a little will cause your mileage figures to plummet about 10-15 percent. A BFG AT should get you what you're looking for. The sizes are available for your stock Jeep and with proper rotation and inflation should last around 40K miles and help you retain your high mpg numbers. The traction off-road is very good, especially when the tire pressure is dropped to around 8-12 psi.
Seeking An Extra Shift
Three easy questions: I have an '03 Rubicon.1.Is the manual six-speed a better transmission?2.Is it a direct replacement for the manual five-speed my Rubicon came with?3.And what are the gear ratios for the five- vs. the six-speed?Paul BiriVia e-mail
1. The six-speed is perhaps a more drivable and civilized transmission, but probably not as durable as the NV3550 your Rubicon came with. The six-speed is a Jeep transmission. The NV3550 is a 1/2-ton truck transmission.
2. It isn't a direct replacement. While there is a provision for a crank sensor, it is in the wrong place and your crank sensor won't bolt in; further, the bellhousing and tranny case are one integral unit. It does share the same T-case spline count, so the NV241OR will bolt to the back.
3. NV3550: 4.01, 2.33, 1.39, 1.00, 0.78, 3.57 (Reverse); NSG370: 4.46, 2.61, 1.72, 1.25, 1.00, 0.84, 4.06 (Reverse).
As you can see, you've got a more durable tranny with a deeper overdrive. I'd stick with what you have. Check out "Six-Shooter" in the June '08 issue for more info on swapping the NSG370 six-speed transmission.
Factory No Fool
I have an '04 Jeep Wrangler Sport (manual transmission) with a 4-inch suspension lift and 33-inch tires. I plan on towing the Jeep behind my cargo van 1,400 miles using a towbar attached to a heavy-duty aftermarket bumper on the front of the Jeep.
The '04 owner's manual (page 205 through 207) says to put the transfer case in Neutral and leave the steering wheel unlocked and the manual transmission IN GEAR. It says putting the transfer case in Neutral disengages both front and rear driveshafts, leaving the transmission free no matter what gear it is in.
The question I have is this: Wouldn't it be better or safer to leave the manual transmission in Neutral also? I don't see the benefit of leaving the stick engaged. I've had several queries out to Daimler Chrysler, and all they did was continue to refer me to those pages in the owner's manual. They refused to add anything or clarify anything. The dealerships don't even know. If something slipped, such as the transfer case, then what? Do you have any particular advice on how to do this as safely as possible? I'm looking for any way to prevent problems since 1,400 miles is a long haul and I don't want to wreck my rig.G. Eberly Via e-mail
Leave the tranny in gear and the T-case in Neutral as the manual says! The reason you do this is to keep the transfer case input from spinning. This is common practice with nearly all Jeeps. It's a little complicated to explain, but essentially you don't want any residual spinning to find its way to the tranny. The parts inside the tranny may not be lubricated properly without the input spinning (engine running). Basically only half of the tranny would be spinning, possibly starved for lubrication.
Trust the owner's manual on this one. It should not accidentally pop into gear while being towed. Make sure you shift it properly into Neutral; I have the same manual and it explains what to do very well. Just make sure you keep stacked luggage and other stuff off of and away from the shifter. -John Cappa