E-450 Ford Rear Suspension Options?

DesertRatt · 12-07-2021, 08:12 AM

2004 Minnie Winnie WF329K Ford E-450

We've now logged about 5,000 miles on our rig in the past 18 months, and for sure the most annoying aspect is the crudeness of the rear leaf spring suspension. It feels crude and untamed.

Since getting the rig we put on new Michelin XPS tires, Bilstein shocks, and Hellwig bars front and rear. The driving and handling are now fine, but that bang!bang!banging from the rear axle is buzzkill on concrete roads. I weighed the unit and adjusted tire pressure downward according to Michelin specs.

Just looking at the rear suspension it looks crude, like a dump truck. Is there a system where the leaf spring could be replaced with air bags or something more forgiving of road cracks?

**creativepart** · 12-07-2021, 08:47 AM

Many Class C RVs come factory equipped with air bags on the rear. Back in 2015 we bought a new 31’ Class C (Ugh!) and it had rear air bags. The air bags didn’t help with banging on rough roads, etc, but were there to help with weight and sagging. They did help some preventing the rear of the coach from bottoming out too frequently.

The leaf spring suspension was invented for the horse and buggy era and is crude but effective for dump trucks, gravel trucks and delivery trucks worldwide. Unfortunately, it has become the suspension for all Ford F53 based motorhomes. There is not much that can be done about it. Liquid Spring makes a complete rear suspension replacement for gas Class A motorhomes but it costs $12,000+ to have it installed. And they’ve just introduced a new front suspension version too. Another $12K. Two manufacturers are offering this as an option on new gas Class A RVs. But I don’t think it’s available for Class C RVs.

DesertRatt · 12-07-2021, 09:11 AM

Thanks C. As always, a great source!

Right. I forgot to mention that we have the "airbag option" on our Minnie, but it seems to do little. We have a lightly loaded RV. If i recall, our original RV service guy set them to 80# and said leave it there.

**creativepart** · 12-07-2021, 10:36 AM

Quote:

Originally Posted by DesertRatt

If i recall, our original RV service guy set them to 80# and said leave it there.

I would disagree with the one setting fits all advice. 80psi is pretty high and might make them rock hard and make the banging worse if you are lightly loaded.

Time to experiment. Try 45 to 60 psi making little 5 psi changes at a time and see how that does. Also, on level ground measure front and rear height and play with the air bag pressure to achieve level front to back. Then check the rear side to side, too. Note that you may need to have different settings for the left and right side. Level is good.

Every RV is obviously different, and ours was a very heavy very long Class C (Forest River Forester 3051S - not good). I think we settled at about 55 psi.

By the way, the ride comfort at 80 psi was vastly worse than the ride comfort at 60 psi.

PS. You should check the pressure frequently. I usually did so before the start of every trip (not every day, the first day of the trip).

DesertRatt · 12-07-2021, 02:41 PM

Super! We're on a trip now, so good time to experiment! I'll let you know how the lower pressure works tomorrow.

TravatoJohn · 12-07-2021, 06:45 PM

I had a 2003 E450 chassis on our Lazy Daze. Biggest problem is the 16 inch tires I suspect you have. I always ran 70 lbs in the rear tires which seemed to help. My weight on the rig was 12,500 at the time and never had any problems. Good luck, Travato John.

DesertRatt · 12-08-2021, 01:17 PM

Quote:

Originally Posted by TravatoJohn

I had a 2003 E450 chassis on our Lazy Daze. Biggest problem is the 16 inch tires I suspect you have. I always ran 70 lbs in the rear tires which seemed to help. My weight on the rig was 12,500 at the time and never had any problems. Good luck, Travato John.

Hi,
Yes the 16"ers on Such a heavy vehicle are too small. I run 65psi in the rear and 55 psi front. That made a big difference from the side wall maximum that my tire dealer set them all to.

Montanwyo · 06-27-2022, 07:26 PM

Check out {TIMBREN} @ E-Trailer, I just did our rig on all 4-corners,,,,, BIG Improvement, Hands Down.....

Our Rig, 2018 FORD E450 Winny 31K.....

l1v3fr33ord1 · 06-28-2022, 03:33 AM

DesertRatt-

You could call the folks at Kelderman. They make a product for 2011-and-newer E-series chassis (link here). They may have one for a 2004, or ideas on what their competitors may offer.

A number of shuttle buses use the E-series chassis. You'd think ride comfort would be important to that business. Maybe if you came at it from that direction...