Super Dragpack

Hi all,

For years I have been using an MPV to tow other vehicles using an A-Frame. I have never had an issue, and although the steering can occasionally be "twitchy", (when a large lorry passes at speed for example) I have never feared for my safety or been concerned - even at 60mph on the highway. I generally do around 200miles trips at a time.

Anyway, I purchased the Jeep XJ (1998 4.0 Auto) for the task of towing. It handles the trailers fine, with no problems at all, although a little more power would be nice. Anyway, one of its duties would be to tow the A-Frame which the MPV managed with relative ease (I would never try the trailers with the MPV, they are far too heavy for it). But we have a problem.

Twice I have used it now, and both times it was extremely unpleasent. The steering, even on a straight road is so twitchy it is very nerve testing. I actually had a few scary moments as it wanders uncontrollably out of my lane etc. I have my theories based on the differences between the Jeep and the MPV (see below).

But the worst was on Sunday morning this week. I was towing a 1.4tonne car. A car I've towed many times before with ease in the MPV. However this trip was fair worse. As the roads were wet (not uncommon here in the UK), it appeared the tow car had better traction than my Jeep. At every sharp turn or roundabout, as I turned the Jeep the tow car continued to steer straight ahead. This would drag the back of the Jeep across and result in a very elegant slow motion drift. I had the Jeep in 4WD, so it would always pull around in the end, but sometimes I was concerned that I didn't have enough space for this fancy vehicle dance.

My theories for the extra twitching and the steering issues are the following:

* The Jeep has larger tyre walls, which give more. Maybe the tyre walls were bending/giving instead of forcing the tow car to steer and follow accurately. This would cause "twitching".
* The Jeep has leaf springs on the back, which give more. Maybe the axle was moving side to side instead of forcing the tow car to steer and follow accurately. This would also cause "twitching".
* The 205/55R16 tyres of the tow car have more grip than the tyres I have on my Jeep (General Grabber M/S), hence why it would push the back of my Jeep instead of being forced to follow.

My Jeep weighs in at 1.84 tonne, as its fitted with LPG tanks etc and was loaded with tools too, (I had it weighed two weeks ago) the car I was towing is under 1.4tonne.

I've previously towed 3.5 tonne+ with the Jeep, with no problems at all (short distance). Here in the UK, it is legally rated for 3.25 tonne and I have towed this weight frequently with no concerns (except the lack of power).

I have sufficient power, sufficient braking, BUT the twitching and lack of steering on occasions is a concern whilst towing the A-Frame.

Just to disprove any theory that its the wheel base of the Jeep, or weight, or similar, the MPV I have used for years, without a single incident like this, is a 1998 Fiat Ulysee 1.9 TD which weights 1.35tonne, has the same wheel base, but with 205??? road tyres and a trailing arm rear suspension setup.

I am now considering selling the A-Frame and buying a 'swivel bed towing dolly'. I used to use one of these before I had the A-Frame and it worked well with the 4x4's I had then.

Any other suggests on the twitching and steering problem unique to the Jeep?

Morat

Is the tow ball higher on the Jeep than the MPV? You might be getting too much nose weight and unloading the front wheels of the Jeep - especially if you've loaded the back of the Jeep with all the LPG tanks, tools etc.

Super Dragpack

Good suggestion but no, the tow ball height is the same. I have an adjustable bracket in the Jeep (it is stock height suspension), so I set it as I want it.

The other thing to note is that the A-Frame doesn't load the ball at all, it just drags off it. The A-Frame simply pulls the car along, it carries no weight itself.

Thanks for the suggestion though.

Mick

Radi

Odd as it might sound, I think you might have too little tongue weight in relation to the towed weight.
Trailers with less than 10-20% of their total weight on the hitch tend to be unstable, a condition made worse by tow vehicles with a long rear overhang in relation to the wheelbase (Jeep) and leaf-spring rear without a good rear track bar (Jeep).
Is it possible to move the axle on the trailer back to increase tongue loading?

Super Dragpack

Although the picture below is stolen from another Forum, this is the same as the A Frame I have. As you see, there is no way that you can load the hitch. The A Frame simply drags the tow car which is forced to follow. You obviously keen the steering lock OFF on the towed car, and the camber of the wheels allows it to simply follow.

I've happily used this for years, but why is the Jeep causing so many problems?

Radi

Ah. I was picturing a flatbed-style trailer, not a wheels-down tow setup.
There was another member here with a similar problem, the trailer didn't seem to want to follow the Jeep around corners. I'm not sure what the resolution, if any, was.

Super Dragpack

I will investigate the idea of fitting a Panhard rod to the rear axle, which is already fitted to the front on an XJ anyway.

I will also either replace my 205/70R15 rear tyres with 235/75R15 (which was also an option for the XJ) or get another set of wheels and get some better road tyres for towing only. I was thinking about getting some 17" Patriot wheels with wide road type tyres to improve my rear end grip when towing.