Wrangler, Grand Cherokee, Cherokee Questions Answered in Jeep Creep

Mar. 28, 2016 By Jim Brightly, KF7SCT

In your Jeep Creep questions, please list your first and last names, your hometown, and your state/province/country, so that we can publish that information here. If you don’t provide this information, we may not be able to publish your question and answer. Don’t forget to be as complete as possible with the description of your Jeep and its problems, too. Send your Jeep questions to [email protected], Attn: Jeep Creep.

More Jeep Creep Q&As
February 2016

January 2016

December 2015

No Jeep recalls from NHTSA this month

Jeep Towing
I have a 2011 Jeep Grand Cherokee with Quadra-Drive II that I flat tow behind my motorhome. In an early version of my owner’s manual (second edition) it says, “in preparing to tow procedure, to turn the engine off and leave the ignition in the unlocked Off position.” It also states to disconnect the negative battery cable. In a newer version of the 2011 owner’s manual (sixth edition) it states to turn off the engine and remove the key. This manual says nothing about disconnecting the negative battery cable. My question is: will any damage be caused to the locked steering column or the front tires using this latest procedure?

Jim Zaleski, F249438
Riverview, FL

I just went online and read the version Jeep is using for the Internet (I don’t know what edition). Its version is the same as what you quoted in the second edition. Either way, the steering wheel must be unlocked so that the front wheels can follow your motorhome. Otherwise, severe damage will occur to the steering and tires. You can eliminate disconnecting the battery—if you wish—by connecting the chassis battery on your coach with the battery in the Jeep. This will maintain the Jeep’s battery’s charge. You MUST have both ends of the charging wire fused close to the battery connection (25A).

I remembered what I used to do when I flat-towed my ‘07 Wrangler. I don’t like driving more than 3 or 4 hours at a stretch, so we’d stop for coffee, a stretch, or for fuel. During the stops I’d start the Jeep’s engine and let it idle during the stop. This practice would keep the Jeep’s battery nicely charged. If you have remote starting on your Jeep, you don’t even have to unlock the door. Simply start it and stop it with your remote. You could even idle the engine while you’re towing as long as you don’t forget to shut it off. With this method you wouldn’t have to install a charging circuit.

Gunky Gas Gauge
I have a 1988 Jeep Grand Wagoneer and the fuel gauge reads over full. Can you help me with a cause?

Terry Smith
Cheyenne, WY

Unplug the sending unit to see if the gauge drops to empty. If that happens, 9 to 1 it is the sender. If not—and if you're not confident with electrical work—find a good electrical shop for diagnosis. Also, if you’re comfortable doing your own work, buy a good shop manual with a good troubleshooting section. They’re available at nearly all auto parts stores.

Bad Cat?

I have a 1997 Jeep 4.0L engine with a manual tranny and the catalytic converter has gone bad. Can I (and will the Jeep run) remove the catalytic converter? Legality aside, will it run better, worse, or not at all? Any modifications needed? Of course, I am concerned about the legality but still have the question—what would one do with the sensor that is now in the converter? I have been getting mixed answers about the effect of disconnecting that part and the engine computer allowing the engine to operate. In theory, of course, do you have any thoughts on disconnecting the sensor?

Gregory Olsen
Manchester, NH

You must keep the catalytic converter in that model year Jeep. Be advised, though, that if you modify your federally legal exhaust/smog system, you could be opening yourself to legal problems and licensed exhaust shops won’t touch it thereafter. Gregory, you can, however, change it to a high-flow performance catalytic converter. If your Jeep has a second O2 sensor at the cat, the cat must work and the sensor must be retained or the ECM will not see before- and after-cat readings, then the engine check light comes on and performance in some cases may suffer. If the replacement converter does not have a sensor receptacle, and muffler shop can weld one into place.

No Front Drive
I have a 1991 Jeep Comanche with a five-speed transmission and 4.0L engine. When I lock it into 4-wheel-drive it gears down like it’s locked in but the front tires will not pull. Do you know where the vacuum or the actuator can be found?

Mike Harris
Somerset, NY

As you’ve surmised, your front differential is not being engaged. It’s either a bad or disconnected vacuum hose or a bad actuator. Your actuator is on the passenger side of the differential. The vacuum hose you need to make sure is not leaking is attached to it. The hose then runs up into the engine compartment. Check the websites of 4-Wheel Parts, Summit Racing, or Quadratec and order the shop manual for your Comanche; it’ll give you instructions on this repair.

Jacked WJ
I have a 1999 Jeep Cherokee XJ that I have lifted a few different times. I’m sitting on 10 inches of lift. Looks great! My wife has a 1999 Grand Cherokee WJ and she wants hers to look kind of like mine. Anyway, my question is, will the coil springs from my XJ fit on her Grand Cherokee? The reason I’m asking is because I have four different sets of springs that I’ve paid a lot of money for and I’d like to use them. And I can only find 2- or 3-inch coil springs’ bushings to lift a WJ.
Jeremy Fulton
Nashville, TN

The springs can be made to fit but not correctly. You’ll have to do so much modifying to the WJ for the XJ springs to work, you’ll be better off to go with a new lift kit for your wife’s Jeep. I found a Skyjacker 8-inch lift kit—including shocks—at Quadratec. Will two inches less satisfy your wife?

Bad Vibration

I have a 2000 TJ with a 3-inch lift with 33 BFG All-Terrains. I had a pretty good vibration starting in the front end that slowly moved to the back. I removed my front driveshaft and the vibration was pretty much gone. The U-joints looked fine. I have heard something about balancing driveshafts but I don’t know anything about that.

Preston Daniels
Bisbee, AZ

Did you separate the two parts of the front driveshaft during the lift install? If so, you may need to “reclock” the two halves into one driveshaft. Both U-joints have to be aligned with each other (the “X’s” must match). If that doesn’t work, take it to a good driveline shop and have it balanced. It has to be balanced just like your tires so that it won’t vibrate. It could also be caused by the driveline angle at the transfer case—you may have to shim up the front differential to reduce U-joint angle.

Mix & Match?

I’m curious. I had a 2002 Jeep that was torched—it was my baby. I bought an older ‘91 Jeep that I want to fix up now. I have the soft top from the 2002; will it fit on my 1991? Do they make one-piece hard doors with roll down windows for the ‘91 (I have the hard doors with slider windows)? Or, how about using a top from a 1983 Jeep? I am guessing the 2002 was a YJ (it was a Wrangler Sport)? The whole top thing has had me so confused. I also need some covers for my roll cage as it is two different colors right now. Are those interchangeable through the years?

Les Lane
Why, AZ

I hope I can pick out and answer all the questions here. First of all, the TJ top will not fit the YJ. Yes on the doors, but they must be YJ doors unless you want to mess with modifying CJ mirrors and hinges. The CJ top should fit the YJ. No, Les, the 2002 is a TJ, debuted in 1997, replaced with the JK in 2007. The 1991 is a YJ (1986-1996, square headlights). Roll bars are model specific, not year specific. What year Jeep do you need hard doors for? Hard doors with roll-up windows have been made for all Jeeps (except CJ5) since the CJ7 debuted in 1976.

XJ Treads
I have a ‘99 XJ Sport with a 4.5-inch lift. I have to get new tires and I know I want to go bigger than the 31s that I have right now. The big question is do you think I would be able to fit 33x10.50s or would it be better to go with 32x11.50s? I prefer the 10.50 for cutting through the snow but since they don’t make the 32-inch in a 10.50, do you think I could clear the 33s? My thoughts are that if I get the 33s, since the tread is narrower, that I wouldn’t be running much more risk of rubbing with that then I would with the 32s. I have 8-inch-wide rims with a 4-inch offset (if that helps at all). Please, any input would be greatly appreciated.

Christopher Sienna
Newport News, NJ

I don’t believe the added half inch height on the 33s will adversely affect your Jeep, and you’re right, the more narrow tires will work better in the snow (as long as the treads are open and self-cleaning). With the height and rim offset, you could probably use 35-inch tires if you wished, but then you’d probably need to change differential gears as well.

Fault Codes
My ‘93 YJ with a 4.0L engine has caused the fault codes 24 (throttle position sensor) and 14 (MAP sensor electrical) to come up on the computer read-out. I replaced both sensors but I still get the 24 fault code. Any suggestion on what might be wrong to cause the 24 fault code?

David Jones
Tampa Bay, FL

You have a possible alternator problem. It could be a bad ground, bad power connection, or bad ECM. Start with the battery ground and the engine-to-frame ground strap and work outward from there to verify that each ground connection is tight and clean.

Locked Up
I have a 2006 TJ Model X with drum brakes in the rear. I had work done on the brakes recently. They installed a new master brake cylinder and a remanufactured power brake booster. Now when putting the brakes on at a speed of 15mph the rear tires lock up. I have been told that this is a Jeep thing. Can you give me a better idea of what I should be doing to fix? I do not feel safe. I was told the issue I was having is an anti-brake lock issue.
ay Dewar
Phoenix, AZ

One of the reasons I sold my ’07 and bought my ’05 LJ was to get rid of ABS. I don’t like it. And I don’t like what it does to the Jeep if something should go wrong with it. I can’t say for sure if your Jeep has ABS because it was only available as an option on a few models but not all. My thoughts are this: If you didn’t, you should have taken it right back to the brake shop. Your rear brakes should not be locking up. The shop got debris of some kind on the drums and they may have to be resurfaced now.

In your Jeep Creep questions, please list your first and last names, your hometown, and your state/province/country, so that we can publish that information here. If you don’t provide this information, we may not be able to publish your question and answer. Don’t forget to be as complete as possible with the description of your Jeep and its problems, too. For some reason the questions have fallen off, and I know we haven’t answered all your Jeep technical questions. There are no dumb questions; only unasked questions. Send them in and try to stump us.—Jim Brightly

As usual, each month, I’m shouting out a huge THANK YOU to Paul Schupp at Rock Lizard 4x4 in Kingman, Arizona, for his invaluable assistance in answering many of the Jeep Creep questions.

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