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Old 04-23-2008, 03:52 PM   #1
viking
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Default Air Lift for Tow Vehicle

I have a 2000 Jeep Grand Cherokee. When I had new tires installed the tire store that did the work suggested that I put on the larger size tire that was suggested for my vehicle. When I attached my 3326 TM to the back of the TV the tire is about 1.5 to 2 inches from touching the top of the wheel well. I am concerned about bottoming out if I hit a bump. To solve this problem I thought I would install an air lift kit that would go into both of my coil springs on the back of my TV. Just another piece of background information I have an Equalizer WDH installed on the TV and TM.
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Old 04-23-2008, 05:46 PM   #2
Bill
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Oops! Oversize tires have a habit of doing that. They also throw off your speedometer, of course, and may confuse the transmission computer a bit.

I suppose that an air lift would do what you want, but be aware that it must not be used to replace the WDH function of the Equalizer. A solid (permanent) lift on the Jeep would be better, as in install the solid lift, re-aim the headlights with no trailer attached, and then hitch up and use the Equalizer to equalize the load, as it is intended to do. The wheelbase on that vehicle (105.9 inches?) is awfully short, and you're going to want all the control you can get.

Or go back to your tire guy and ask him to replace the oversize tires with the right size tires.

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Old 04-23-2008, 09:31 PM   #3
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I don't know about oversized tires, but I had air bags put on my Ford Ranger when I was using it as a tow vehicle for our 3023 and it made a world of difference in the ride (yes, I kept the WDH, too). I had a controller put in the cab so I could add/remove air as needed. Worth every penny.
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Old 05-05-2008, 06:34 AM   #4
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Default Air Shocks vs. Air Bags for Coils

I took in my tow vehicle today to get air bags put in the coils to keep the back end from sinking down while towing my TM 3326. When I got there the tire dealer told me that I should put air shocks in instead because according to her it would do the same thing and be less money. I will also be using a WDH always while towing. What do you think?
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Old 05-05-2008, 08:07 AM   #5
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I am certainly not as expert as many on this forum, especially in the use of a WDH. Are you getting the back end sink while using the WDH? If so, then I would think it is not adjusted properly. If the rear of the TV sinks without the WDH, this would probably be what you would expect. As I understand it, the WDH is designed to take weight from the TV rear and distribute it to the trailer tires and to the front end of the TV, keeping your TV level. Get a ruler and measure from the ground to the center of the fender on both the front and back wheel of the TV when unhitched. When hitched, using the WDH, measure again. If the front and back of the TV did not sag approximately the same amount, then you have a WDH adjustment issue.
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Old 05-05-2008, 08:33 AM   #6
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With the WDH I am getting the same amount of sag. The problem I am trying to solve is that the back tires with the WDH are too close to the wheel well and I need to lift it. So back to the original question is there an advantage to using an adjustable airbag in the coils vs. an adjustable air shock to raise the back end higher off the tires.
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Old 05-05-2008, 09:26 AM   #7
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I'm not sure how to help you with this one, because you are doing something that is very unusual. As we have discussed, air shocks / air bags are generally "forbidden" as a way to level the vehicle when you add weight to the rear end - and that is what you keep describing as one of your goals.

If you are going to continue down this path, your first step is to modify the Jeep's suspension to get the tire-to-wheelwell clearance you need, before you add any load. With no weight on the hitch, install the air devices and pump them up get the clearance you need. This is the new permanent position of your Jeep. You've jacked up the rear end, you have the tire clearance that you need, but the headlights are pointed down. So adjust them up to the proper aim, and you are good to go, with or without a TM. My question at this point is why not do this with a solid lift, instead of air devices? At any rate, at this point you can go ahead and use the WDH as it was intended, to provide weight distribution without juggling the rear end height any more.

Your Jeep now has a new definition of "level". Next step, as Scott said, is to measure the distance from the fender wells to the ground.

Now add the WDH and the TM. The rear end of the Jeep will sag - but do not pump up the air devices to compensate! Instead, crank up the WDH springbars so that the Jeep is again level by the new definition, and the headlights are again pointed in the right direction. You can tell when the Jeep is level by measuring the distance from the ground to the fender wells once more. When you've got the WDH right, the front and the rear will both have settled by the same amount, and at this point, the WDH is doing its job. Incidentally, once you've got the WDH right, I wouldn't expect the front and rear to settle by more than 1/2 inch or so. If this matters, then your oversize tires are really too oversize.

I know this wasn't your question, but I'm not sure anyone can advise you because you're trying to so something very unusual (so no one has experience), and you continue to describe doing something that is technically unwise. And it is complicated by the fact that the Grand Cherokee has such a short wheelbase, which makes proper use of a WDH even more important.

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Old 05-05-2008, 01:30 PM   #8
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Viking...sorry I missed your 2nd sentence! Changes everything. As Bill said, you are in sorta uncharted territory. When I put larger tires and wheels on my Tacoma, a also added a 2" lift kit to both ends. This allowed me to keep my wheel well/tire clearance when I hooked up the TM. If I understood Don correctly, this is what he was suggesting. Probably not as inexpensive as air shocks, but a better way to go in my opinion. And it would give you more ground clearance in your Jeep if you want to do any off-roading...
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Old 05-05-2008, 03:20 PM   #9
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Dunno about Don, but that's certainly what I had in mind ... Thanks for stating it better.

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Old 05-05-2008, 08:16 PM   #10
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Many apologies and begs for forgiveness Bill Bill Bill Bill Bill Bill Bill...the 65th birthday seems to have taken a quick toll!
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