suspension strengthening!!

[copperman]

. I am a piledriver/carpenter/certified welder/commercial diver. From job to job I have to tote around alot of gear. 500lbs or better. My 89' jeep grand wagoneer just started sagging abit with its factory suspension. I've been thinking about getting new shocks to try and improve the sag. Maybe raising the rear an inch or two. Possibly adding leafsprings or new, improving its rating or carrying capacity to 1/2 ton or 3/4. But I don't want to loose the smooth glide of the ride. I know absolutely nothing about this subject so any help is appreciatted! Happy New year!! :confused:

[River Beast]

Welcome....

IF you beef up the suspension to carry more weight, you will deifinitely lose the cush ride.... You can add leafs to the rear to stop the sag.. such as Rancho full length Add-a-leafs or go to a local boneyard and find suitable leafs from a Chevy and put them in your existing packs using new centering pins on the leafs... that's the cheapest way to go to boost the rear...

remember.. adding leafs will ulitmately raise you up some when unloaded and give you a stiffer ride...

Have you thought of those cheap add-on overload springs? just a thought....

[waggin'ear]

The overload springs are a good idea. I have them in my '79.

They are cheap and easy to install and will cure the sag problem.

They will stiffen the ride when you are not carrying anything, but the ride is great when you have a couple hundred pounds.

[Bob Barry]

You may want to consider airbags to level the rear of the truck; there is apparently a kit that bolts to the top of the leaf-springs and has a receiver that bolts to the side of the frame-rail. This was detailed in FSJ Magazine some time back, I think. Mike Ahlman is the guy who did the install; I don't know if he's joined us on this board yet.

Don't be concerned with that weight, though; your GW can easily carry a 1000lb payload and still be under the factory GRVW.

[Dan G]

Copperman,

Cheapest fix is either add a leafs or the overload springs.
I just put a pair of the 1500 lb COIL 'helper' springs in the rear of my 87 GW. They bolt to the axle and land on the frame right where the bump stop was. Stiffened the ride to hell, however, I can continue to abuse her without worrying about the stock springs giving way. I needed to relocate the brake lines a bit by merely prying them out of the way. Springs were like $24 at Pep Boys.

Plus I'm at least at stock height in the rear, maybe even 1" higher. I've got the same plans for the front (poor man's lift kit) as I plan to mount a snow plow.

[Sgt. Dave]

I like Bob's idea. I had Firestone air bags on a Ford F250, and they were great. You can either run an on-board compressor, or air them up externally. Pressure range was a min. of 3 psi, max of 90psi. Plus, you can compensate for unequal loads from side to side. They aren't real cheap, but not too bad. I even pulled a leaf out of the F250 to soften up the springs, and let the air bags pick up the load. It rode s m o o t h........

[Stuka]

I have heavy duty monroe's in the rear, which when added to the already stiff suspension (factory 5/8 ton) the back end is beyond stiff ont he road. Unless I have about 600 pounds or so int he back its a bone jaring ride. But it takes the weight well.

[nograin]

My .02

For taking the consistant extra weight, springs are where you want to make any changes.

Shocks basically help control motion. For example in automobile racing, shocks are the place to concentrate on when dealing with transitions (eg slaloms), as opposed to steady state (long sweeping turns).

Springs control your steady state conditions, and are also what carries your vehicle.

You didn't mention cost as a factor, so I'll ignore it. 500 lbs over the rear axle is pretty reasonable. I would not be suprised if putting in New springs (or having the old ones rebuilt and rearched) to stock specs would deliver what you are looking for.

All springs lose a little tiny bit of spring every cycle, so in 60-80 K miles, you will be down a little from stock height I expect. If you are always carrying the 500+ lb. load, then a helper, or slightly stffer spring would still produce a pretty good ride.
But, if you drive withoit the extra weight, thats when the stiff springs will transmit the road surface to the entire vehicle. So, if you drive with the extra load only some of the time, then the air-bag helper "springs" would appear to be the best solution.

IMO air shocks are not the way to the smooth ride you were trying to keep. You want a shock that dampens motion, not one that is holding the weight - thats the springs job.
If you are consistantly carrying a much greater load, you may want a slightly stiffer shock to reduce roll in corners or improve control. Deal with this after you take of the springs however. If you do, and wish to experiment, the adjustable RS9000 may be something to consider.

One final point, if you stiffen up the rear suspension relative to the front, it will make the back more likely to come around. :eek: If you add more weight for the rear suspension to carry, the opposite is true. smile.gif To much, and the front tires won't bite well when cornering redface.gif

So from a handling perspective, more weight and stiffer springs on one end of the vehicle go together. If its only a part time thing, then the adjustable "load levellers" or the like are the way to go.

[Sgt. Dave]

Just to clarify, we're not talking about Air Shocks. The Air Bag system is an add on between the axle and the frame. It will not stiffen the suspension unless you really pump up the pressure. The main purpose is to allow you to level the vehicle, and compensate for heavy loads without compromising the unloaded ride. These systems (Firestone Ride Rite is the one I've used) are designed for full time use and will probably outlast the springs. If you want to see the large economy size version, look under a big rig or road bus. Same thing.There is even an outfit that pretty much replaces the stock spring system with these. Think its "Kelderman Air Ride". www.keldermanmfg.com (http://www.keldermanmfg.com)