Sagging rear: re-arch + extra leaf or airbags?

[AndrewST]

The trailer level is given by the hitch height.
The trailer load will bring the rear to sag even more then not loaded.
Might be good to see if unloaded it sits as low or not.
Options are air bags for when you tow and or new leafs...

[jage]

Originally Posted by Ocsmb

Trailer looks pretty level to me but I think you're right the rear leaf pack might be tired

Trailer level is a achieved by height or drop of the hitch ball, not how much the tongue weighs.

Have you weighed you tongue loaded? That seems low even for flat springs. Make sure your trailer is loaded correctly before you address the symptoms.

[carringb]

How much is the front lifting when you hitch up the trailer? This is where the weight-distribution hitch comes in. You may even need to drop the hitch height as you increase tension on the weight-distribution bars.

How does the van sit without the trailer? If its sagging un-hitched, then leaf springs should be adjusted/added to establish the desired static ride-height. Then, use airb-bags to address weight added beyond that, but only if ensure proper weight distribution (using the hitch) first.

And finally, don't forget to weigh your rear axle when hitched up. You may be over the tire and/or axle rating. If you have a semi-float axle (it looks like you do) the mechanism of failure is not pretty.

[1der]

What does the van sit like with no trailer? Level?

Looks like hitch height is way too high as trailer is sitting level. A heavy trailer, heavy tongue load, plus too high a hitch would create that exact condition. And, it would put a heck of a load on the springs. If this has gone on long enough, Springs would be worked.

[Ocsmb]

This is how she sits without the trailer.

Didn't realize the hitch ball was to high.

I'm going to swap to a drop hitch ball.

I've got a 3.5" and 5.5" drop.

Will see how the 3.5" looks next.

[carringb]

It does look droopy even without the trailer. I think you would be good candidate for some rebuilt rear spring packs.

I don't think dropping the ball is the solution since the trailer is level. Especially if you have torsion axles on the trailer. They don't equalize like leaf-springs, so and out-of-level will overload one of the axles, and can even induce sway.

[Ocsmb]

I measured height over the center of the rear wheel from the ground to the middle body line and then did the same over the center of the front wheel. The rear height is higher than the front. Still dragging ass?

[1der]

Does not seem like it is droopy based on the measurements, especially in light of the weight hanging off the rear of an extended van. What else do you have in the storage box and behind the rear axle of the van?

I still believe the hitch is too high and possibly the tongue weight is too heavy due to a front heavy load distribution in the trailer. I would try the 3.5" drop and 5.5" drop and see what happens. Repeat your measurements to see what you have with each set up. If possible, play with weight distribution inside the trailer so the tongue weight comes in between 10 and 15 percent of the total loaded trailer weight.

All that being said, if the trailer tongue weight / high hitch combo has been used for lots of towing, the springs may simply not be up to the extra task of supporting the tongue load and may need some helpers.

[1der]

Too late and need some sleep - forgot to add this:

On a relatively flat area, have the trailer disconnected from the van sitting level on its front wheel/pad. Make sure trailer tongue load is 10% to 15% of total trailer weight. Back the van up to the trailer without connecting up. The tongue height on the trailer will dictate approx. what the drop on the hitch should be. Install the proper hitch drop. Take your measurements of the van before connecting trailer and then again after trailer is engaged and fully resting on the ball. You should not see much drop if springs are in good shape and tongue weight is correct (and you do not have a bunch of unnecessary weight in the rear the van) If you get more than a couple of inch drop over the rear wheels, you likely need some stiffer or helper springs/or air shocks/bags.

btw - what is the weight of the trailer?

Ray