Wondering how capable a wj 4.0 would be for pulling a small 3500 lb. max weight travel trailer (Casita)

 

It is within the design limits of the vehicle, but you'd be towing almost exactly the weight of the vehicle itself, so the WJ should be well maintained and in good shape. Personally, I would install electric brakes on a towed weight of that magnitude and use extreme caution. Also, you should forget about using O/D (4th gear) at all. A transmission cooler is a must and watch the engine temperature at all times. Be careful how you load the trailer to keep the tongue weight at a reasonable level with most of the weight on the trailer's wheels. On onboard water tank can change the center of gravity considerably.

 

It could be done. But I wouldn't do it more than a short distance.

 

Exactly.

 

What's the curb weight of the trailer model you're looking at? I'm seeing indication that a 13ft model comes with a 3500# axle under it, but it only weighs 1900#, while the 17ft deluxe model also comes with a 3500# axle under it, but weights 2500#. That may be for older models though... I tow a ~2500# pontoon boat home from southern VA and continue to do so at ~3000# fully loaded multiple times a weekend with my 94 XJ on 31s w/ 4.10s, disc 8.8, towing pads, B&M 70268 cooler. It kicks down to 1st at ~20 mph when going up the 15° grade but down around 10°, it will usually stay in 2nd. Abusing the AW4 for sure, but it hasn't shown an signs of giving up yet, even after a leaking radiator turned the fluid into strawberry milkshake. It's a stout little beast; I'm not sure the WJ transmission is as sturdy, but that's only from seeing people putting AW4s into the GCs, which may have been ZJs...

 

I tow an Airstream Bambi with my ‘03 WJ, very similar set up to you towing a Casita. I’d like to add that you may want to consider a suspension supplement to the WJ rear coil springs in addition to the weight distribution/ sway control bars. I use Sumo coils, CSS-1168, to augment the rear suspension, or some folks like the adjustability of air bag systems, either way, the coil springs can tend to be a little soft/ saggy even with a well adjusted weight distribution control system. The 4.0L engine is a good power plant for smaller size single axle trailers, anything heavier than what you have would be exceeding the design limitations of your rig, I’ve towed all around the western states and if you follow Dave’s recommendations, I think you’ll be fine with your Casita. The 4.0L will get you there, just take it easy on the grades, and if you see an advisory road sign that says: Not Advised for Trailers, take an alternate route, happy travels...BTW Sumo Spring also makes a number of suspension enhancements for your XJ as well as the WJ.