Sumo springs

On my 1990 p30 It had the rear springs replaced. It was starting to sag in the back. Well the springs did level it out somewhat. A couple of years ago I added air bags on the rear to bring up the ride in the back. I was surprised by how it softened the ride in the back. I keep about 60 psi in the back and it has just a slight rake to it.

I mounted Sumo springs on my P32 chassis. It did improve the ride somewhat, but more importantly helped eliminate body roll in corners.

It also helped stop the jarring effect when hitting a bump. I mounted Timbrens on the front with the same result.

The best thing I did was Super Steer springs in front and Rearched and add a leaf in the rear.

the trippers wrote:
Sumo springs, or Timbrens, are designed to prevent sag, to keep an overloaded vehicle more level, don't think they will ever soften the ride. Unless your RV is now sitting on the factory bump stops.
I use them on my 12 yr old pick up truck for carrying heavy loads and maintaining some levelness and control.

On F53 chassis, the Sumo/Timbrens are preloaded. They replace the bump stops when installed. The problem with the F53 chassis is that the manufactures wanted a softer ride, so Ford tried to give them it by installing a light single rate spring. Unloaded, the MHs ride pretty good, but when you get close to the max weight, the free space between the bump stop and springs is well less than 1". Under normal road conditions, this can, and does cause a jarring ride when the springs hit the bump stops. If you doubt this, just put some modeling clay on top of the springs, below the bump stops and drive it. Then measure the clay, if there is any left, to see the results. If Ford would install a dual rate spring sets, much like they do on their heavy duty pickups, the ride would be more than acceptable. Bad roads, and misaligned bridge abutments will still be bad, just as they are in a DP.

Sumo springs, or Timbrens, are designed to prevent sag, to keep an overloaded vehicle more level, don't think they will ever soften the ride. Unless your RV is now sitting on the factory bump stops.
I use them on my 12 yr old pick up truck for carrying heavy loads and maintaining some levelness and control.

I had a Workhorse Chassis a few years back. I did just about every suspension upgrade including Sumo springs to improve the ride and handling. The handling improved somewhat............probably 25%, the ride, maybe 15%. I now have a diesel pusher and the ride and handling is 100% better then gas, plus the noise level going up grades is 1000% better. My DP is on a Freightliner and after market upgrades are available. I plan on zero upgrades, why? it rides and drives great as it is. If I had a gas motor home. I might do some sway bars do help with handling, as far as ride, it's been my experience, it's basically money down the drain. I've had two gas motor homes one I just did shock upgrades and again, no difference, the other I talked about above. I've found that quite often when people spend money on an upgrade, that they've convinced themselves into a positive improvement no matter what the outcome, so will talk positive about the product.

Sumo or Timbren springs replace the bump stops, or snubers, that are on F53 chassis. These bump stops are what cause the rough, jarring ride, as there is very little room between them and the springs when loaded. They will help smooth the ride, but as mentioned before, will not make it ride like an air suspension rig. You can try to lower tire pressure to improve ride, but I found the increasing the front to 100 psi and the rear to 90 psi has improved the ride and handling.

Also lowering the PSI in your tires by 5psi can make the ride a lot smoother. You will burn a bit more gas though.

I replaced the hard factory Bilstein's shocks with Monroe RV soft shocks and there was a difference, start there 1st, its cheap.

A lost cause trying to get a F53 to ride like a DP chassis. You're talking about a old school straight axle v/s independant suspension. The up side is that the Ford only has 4 grease fittings on the axle and if you keep them greased, the front end will never wear out. A lot more moving parts to fail on the Diesel BUT you get the nice ride. Unless you are regularly bottoming out the suspension on the F53, the Sumo springs won't make the ride much softer but if you are where potholes are a big problem, the Sumos will take a lot of the crash out of them.