4 Wheel Drive/SUVs/rear suspension

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Expert: - 10/6/2004


Question
Hi, I recently bought a 1973 ford F-100 4x4 short box. It has a 4.5 inch suspension lift(rancho).It has a steel flat deck on it, which is heavy. I notice when the truck is on level ground, It sags in the rear, and when I put my atv on it really sags. I was wondering what would be the simplest way to fix this. ( More leaf springs, or lift blocks).  

Answer
Chris,

This is a very common problem.  Try to stay away from blocks, as they put more strain on the springs in the form of axle wrap.  There are several things that you can do to help reinforce the rear springs.  You can go with air bags, booster springs, overload springs, etc.  The best way to start, would be to contact Rancho, and see what they suggest.  I would suspect that they would suggest an additional spring due to the weight.  You can purchase a few 4x4 magazines, and contact some of the parts distributers, especially ones that specialize in lifts, and see what they might offer.  This is a hard one to answer with one solution, as many of the options available, are left up to personal preference.  You can ask 5 off road drivers, and you will get 5 answers as to which system is best.

Carl  

4 Wheel Drive/SUVs

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Carl Brandt

Expertise

Will discuss suspensions, lifts, lockers along with tire suggestions. Trail ratings and possible requirements needed for specific type of trails. Safety equipment and what you should carry with you. Certified off-road instructor. I am not a mechanic, and 4-Wheeling is a hobby, so if I can't answer a technical question it is due to my mechanical knowledge being related to vehicles that I have owned, or have worked on. I do not have manuals on all vehicles.

Experience

40 plus years of 4 wheeling in a variety of vehicles. At the present time, my major off-road rig is a 94 Jeep Wrangler with a spring over and a 1 1/2" suspension lift. This gives me a total lift of 7" or so. I have lockers front and rear. I have removed the track bars, and sway bar for maximum articulation. I am running a stock 2.5 ltr 4 cylinder with a Jacobs ignition along with a cold air high flow filter. It has 4.56:1 gears with a Dodge NV4500 transmission along with a 3.8:1 Atlas II transfer case. This gives me a final ratio of 105:1 in low gear/low range. Other vehicles I own, are a 96 Ford F-250 with a 6" lift, posi rear end, 36" Hummer tires, 5 speed with a fuel injected 460 ci engine, an 87 Samurai with an 8" lift, Ford 9" rear end with a spool, Chevy Dana 44 front end with an electric locker, 5.88 gears, 16% reduction in high range and a 6.5:1 low range with 35" Baja Claws, and a stock 2003 Grand Cherokee Overland. Trails I have run are the Rubicon (10 times), Dusey Ershim, Fordyce Creek trail, McGrew trail, several trails in Moab, Utah along with local monthly runs.

Organizations
Lost Coast 4x4's Cal 4-Wheel Corva UFWDA Blue Ribbon Coalition

Education/Credentials
Certified off-road instructor - Certificates in engineering/electronics

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