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Mystery Smell From Flat-Towed XJ
Q I have a '92 Jeep Cherokee with a 5.5-inch lift running 32x11.50/15 tires. It has the 4.0L motor and automatic transmission. I flat-towed my Jeep to Moab for a Labor Day event. When we got to there, I started to unhook it from the motorhome. We got a very distinct smell of burning rubber from what seemed like the power steering pump. No funny noises or anything, just the smell. We made a quick check of all fluids and everything seemed okay. The next morning we took off to get fuel, drinks, and to begin our day on the trails. The burning rubber smell went away after our stop at the gas station. We ran two trails over the weekend and had zero problems.
The same smell returned when I got home and unhooked the Jeep again, only this time the steering wheel was off-center. Had the alignment checked and it was okay-just had to re-center the steering wheel. Everything has been fine since. I was thinking maybe I burned up the power-steering pump somehow, but like I said, the Jeep has been fine. I am planning some more trips with the Jeep, flat-towing behind the motor home, and I sure would like to know where that smell is coming from so I can fix it. Any ideas?
A I am not really sure, but I can make a pretty good guess. I don't think the problem is in the power steering pump. There are a couple of clues here. The first is the smell of burned rubber, and the second is the steering wheel now being off-center. Being flat-towed means that the Jeep is pretty darn close to the back of the motor home and you cannot see the front of the Jeep-in particular, the front tires. Several things could be happening. Are you leaving the steering wheel and the ignition key in the Lock position? If so, when you're making a turn in the motorhome, the front tires of the Jeep have to slide sideways to also make the turn. Or if you are leaving the key so that the wheels are unlocked, the tire starts to follow when you turn, but especially in a tight turn, they don't come back very quickly and again the tires slide sideways. This side movement scrubs off rubber.
Could it be that the rubber smell just accumulated under the hood? Did you by any chance put your hand on the tires to check a temperature difference between the front and the rear tires? The fronts will be warmer if the vehicle is sliding sideways. Did you notice any unusual wear pattern on the front tires that would indicate that they were scrubbing sideways? I think that pulling the front of the Jeep sideways is the problem on both the rubber smell, and that the side-loading slightly bent one of the steering components, causing the steering wheel to be off-center.
How to solve the problem? Make sure that the steering wheel is unlocked. A longer towbar, and mounting it lower on the Jeep (or raising the ball mount location on the motorhome) will provide more leverage. Putting a bit more caster into the front axle of the Jeep will also help somewhat, as caster is what keeps the wheels straight when moving forward. Avoid backing when hooked to the Jeep. The rearward direction will cause the opposite effect and has a tendency to cause the tires to go into full lock in one direction.