New springs or add to?

[patrick51]

I am considering a spring upgrade on my 07 4WD E350 SMB. Since a trip to Deavers from Ohio is out of the question now, I have been talking to a local outfit. They have been in the truck spring business for years and have a great reputation. I am wondering though? they have not yet seen the van but agreed to look at it and check the existing set-up and distances on the suspension. They said they have no way of weighing it. They mentioned the possibility of adding to the existing springs to get the 7 or 8 leafs that I hear many SMB folks are going to. Does anyone have thoughts on this? I am using EMU shocks. Like most everyone else we are trying to solve the rough ride problem. Thanks

[j.whitbread]

The rough ride. What's up with that? F350's don't ride like the vans. Is it wheelbase, or something about the frame, or the body of the van? The van body is one piece. The pick up truck bed is separate. Is sitting right over the front wheels part of the problem? Oh well.

I think adding springs will make it worse. When I spoke to Deaver, they wanted to increase the ride height slightly to gain travel but make the springs softer. Not harder, which is what adding springs would do.

Deaver wanted to replace my front springs with taller springs and a softer spring rate. Same concept for the back leaf springs. The additional ride height increases suspension travel and gets the axle further from the bump stops. The spring rate is determined by the vehicle weight. Also less axle block is used. They start with the arch in the springs, then after settling of the suspension, adjust block size as needed for ride height. But it will still be less than the Quigley blocks, in my case.

There must be a competent spring guy in your area. I guess Deaver has done the work on these vans so they are the vendor of choice right now.

[jage]

Getting the Deaver's shipped is a good solution. They know the vans and once mine settled it has been great. The Deavers are actually 11 layers with no real "overload" spring.

My van rode rough because the rear were on the overload springs in the rear, and the front was flat with somewhere between 1½ to 2 inches of up travel, meaning it bottomed out all the time.

My F250 on the other hand rides rough because it's empty. One ¾ and 1 ton vehicles are factory designed to ride best loaded, at or near capacity. Does SMB or Quigley change the rear springs when doing the conversions? I would think that stock springs with the SMB build would not only ride better (not the case in my van) and be able to handle the load without being on the overload springs 100% of the time (also not the case in my van).

Regardless the Deavers are worth considering as a shipped item installed by a local shop. I would be interested in what the shop wants to build custom springs for you though.

[daveb]

Originally Posted by jage

Does SMB or Quigley change the rear springs when doing the conversions? I would think that stock springs with the SMB build would not only ride better (not the case in my van) and be able to handle the load without being on the overload springs 100% of the time (also not the case in my van).

Yes the rear spring pack is different on my 06EB and is not stock. In fact it has a partial military wrap backup spring.

Pat, SMB had changed the rear pack in later 05 (I think) due to complaints about rear end sag. (John K should know). Although my vehicle never did have rear sag even when loaded, I had rear air bags installed just in case. My van is 12K lbs loaded and in 06 it was between 10.5 and 11K when loaded back then. Several owners had an extra leaf or two added on their 4x4's to offset the sagging problem probably more for cosmetic purposes but also for future extra loads. Just before the new 08 came out I think SMB was on the issue for the most part, so the 07's should sit level at least. The 08's are quite different but might suffer from stiff ride (someone with a 08 would have to comment here). I would think Jage is correct on adding a leaf = stiffer ride. My 06 rear spring pack is stiff enough and I would not want to jeopardize the ride by adding a leaf. But your vans total weight could make a difference I would think. Your mileage might vary due to the vans weight. It's going to be a gamble going to Deavers in the rear of my rig because I don't know what I'm gonna get for the money. I might not see that much of an improvement and I just have to take the plunge. Owners claim Deavers should allow more flex for a softer ride, less rear end bounce and an increase in height by about 2 inches. I have no sway or cornering issues but I'm hoping that Deavers can help with bounce. I'm sure some is a shock issue also and I'll probably switch to Bilsteins. Most of my problem is in the front with washboard shutter. It’s wicked. BTW when I'm on a rough road, pumping up the air bags makes the ride rougher so I let them down to 10 or 15 lbs and let the springs absorb all they can. Also when I went to E-rated tires it became absolutely necessary to air down on rough roads. Now that I'm running E tires I'm thinking the drive down south might be worth it. Air bags have problems with leaks and don't last forever. Maybe you can speak with Deaver to see if they can custom build them like Jage said. Just weigh the axles and each tire (corner) on the van and give them the necessary info. Sounds like Deaver has done enough SMB's to be on top of them.

[yvrr]

We had an extra spring added to the rear packs but only because of a sagging rear end. It was done by a spring shop in the Bay Area that makes their own springs and deals primarily with trucks. They didn't need to know the weight of the van (ours is around 10,700)...all they needed to do was make some measurements. I didn't notice any difference in ride (neither better nor stiffer), maybe because our van is so heavy. In fact, my wife, who has back problems, can ride in the van for longer times than in our auto, especially after replacing the OEM shocks with Bilsteins....