Upgrading E350 rear springs - options?

sportcoupe · 12-10-2021, 07:28 PM

My new 2022 Vegas on E350 chassis rear springs are overloaded direct from Thor (IMO). The spring packs bow upward slightly when parked and level. I have not exceeded the CCP rating of the coach.

Or, is a negative arch completely normal in E350 for ride height?

Being the E350 chassis has been around a while, are there upgraded rear springs available? What have you used? I would like a solid 2 inches extra clearance in rear only.

Sorry if this has been asked a million times. I came from Class B Transit.

ducksface · 12-10-2021, 07:44 PM

Deever spring
Santa ana California
They'll build you, from scratch, cheaper than you'd expect, exactly what you need.

They built me a five inch under axle lift for my 2dr blazer.
They'll build my four inch 24.1(I have lift blocks now) lift springs if I ever need them.

sportcoupe · 12-10-2021, 09:31 PM

Thanks duck. Of course the custom places are in CA. I am on the other end of the country in GA. My old body can't do HD suspension work anymore.

Chance · 12-10-2021, 10:30 PM

Ford Media pictures show springs with unusual reverse curvature, even when empty, so it seems normal. The only way to know if you are overloaded is to weigh your rig. The Axis/Vegas on E-350 have 5,000-pound front axle and 8,500-pound rear axle ratings. I wouldn’t guess, but weigh instead. If you want a lift anyway, that’s a different matter.

.

sportcoupe · 12-10-2021, 10:54 PM

I'll weigh. My normal weigh station doesn't have dual scales for front/rear weights. They have a single scale. I'll check for a dual scale in my Savannah area.

LarryD · 12-12-2021, 05:37 PM

many of the Love truck stops have scales on the 95 and 75.

sportcoupe · 12-12-2021, 09:45 PM

Yes, easy to find multi-axle scales along I-95. I'm 40 mins one-way from them. Was looking for a closer scale, found one at a rock and sand store but it's not multi-axle.

I'm sure weight check will prove I'm underweight. That will mean the leaf springs on a E350 HD have a negative arch. A flat arch would give me my 2" height increase.

ducksface · 12-12-2021, 10:35 PM

You can see the negative bend in the above photo of the cutout and bare chassis.
These pictures are
My 24.1 negative spring
My 24.1 4" lift block.

sportcoupe · 12-12-2021, 11:57 PM

Photo above looked a little bit like CGI. Also, don't know if that's before or after Morryde modifications. I suspect before.

Duck, thanks for picture confirming negative bend. I wonder is a 1" block is available? I'm not looking for a huge "lift" at all.

Alternately, maybe a reduced height rear shackle? That would raise the rear slightly.

ducksface · 12-13-2021, 12:03 AM

The blocks are easy.
A block the height you like
Longer u bolts(maybe not needed for just an inch)
A jack.
Potentially, not probably, inexpensive sway bar link extensions.

I'll check my dimensions so you'll know it fits your pad.
And
Check your pad to make sure it's right sized.

It's one of the very easiest mods to do.

Any 4x4 shop has done it 100 times.

sportcoupe · 12-13-2021, 12:46 AM

Googling 1" E350 lift block. Not finding an exact one yet.

I've lifted maybe a dozen vehicles in my life, mainly jeeps. Never a E350 HD.

I have hydraulic leveling that can support the rv (with jack stands).

ducksface · 12-13-2021, 12:50 AM

You won't find a block, you'll have to make one.
I think mine is just a chunk of bar stock.
Very. Big. Bar Stock.

A steel supplier can cut one for you at the one inch you want.

sportcoupe · 12-13-2021, 12:58 AM

No locator pin?

ducksface · 12-13-2021, 01:03 AM

Half inch diameter
I think two of them.
Maybe 1/2 inch high.
Hand drill type work.

sportcoupe · 12-13-2021, 01:19 AM

Well, one side will be a hole, the other side will be a pin.

Positive 1/2? I would have thought the dually E350 would have the larger 9/16" locator pin.

ducksface · 12-13-2021, 01:45 AM

Maybe.
I didn't do the making of these.
Like you I've done/helped with so many and they're all so similar. I've helped with even wooden ones.
It's pins and holes nontheless.
A drill a bolt and a tap if you don't have a welding machine(notice I didn't say 'welder')

6inthefamily · 12-13-2021, 03:37 PM

Here is what I have found out along the way as I have been redoing the suspension on my Thor 29 J E450 Class C toyhauler. Do your own research, but here are the part numbers I have found, and the work I have had done. Half loaded and full of fuel (all other tanks empty) my Class C weights 4600lbs (front axle) and 9320lbs rear axle. 13,940lbs total with a 14,500 GVWR.
Ford states that the Econolines are designed to have 26" between the ground and the top of the frame in both the front and rear. My RV started 22.5"F and 23"R. So significantly lower than where Ford expects the ride height to be.

Rear Suspension
1. RV comes with leaf pack part #43-1791 with 5100lb load rating per spring.
2. First, I installed Sumo Springs part #SSR-130-47 in the rear that provide 1500LBs of support at 50% compression. I also installed Koni FSD shocks all around at this point. With just the rear Sumo Springs/Konis the ride has been improved, but parked the Sumosprings are about 1/8th compressed. (According to SumoSprings their should be a small gap between the axle and the sumo spring while parked) So, I was looking for more lift.
3. After some research and stopping by a local local spring and commercial truck service center to talk with their techs I learned the following. Rear leaf pack part #43-1791 HD is a heavy duty spring pack rated at 7200lbs pre spring. Apparently, this spring size is a very common upgrade for Ambulances and Class C RVs. (I have these on order now)

Front Suspension:
1. The front coils on my E-450 are part # 9C245310XA. I have been told that these are the same from springs that come on E-150, E-250, E-350, and E-450s.
2. A common upgrade for E-250/E-350 Econoline van owners are Moog front springs Part # CC880S. These are progressive springs compared to the linear springs that came on my E-450. Research found that these raise the front of 5.4L E-350s about 2.5", and the front of 7.3 diesel E-350s about 1.5". So I felt comfortable trying these on my E-450 with the 6.8L and bunkover cab. They raised my ride height 7/8", and have been a massive improvement to the ride our RV.
3. Other front suspension changes I have made. SumoSprings SSF-106-40 which are lighter weight that what Sumo recommends for the E-450. They are rated at 500lbs at 50% compression. Koni front shocks.

Overall my Class C is better in every way compared to stock. 5 minutes into our first ride my wife and kids all commented about how quiet the RV got and how less impactful the bumps felt.

Chance · 12-13-2021, 04:31 PM

Quote:

Originally Posted by 6inthefamily

....cut....

Front Suspension:
1. The front coils on my E-450 are part # 9C245310XA. I have been told that these are the same from springs that come on E-150, E-250, E-350, and E-450s.

.....cut....

Ford specifications clearly show about a dozen different coil springs for current E-350 and E-450 Cutaway and Stripped Chassis. Discontinued E-150 and E-250 vans probably had even more spring options due to lighter weight. Even my E-350 Super Duty van has low front axle weight rating so front coils are much softer than your E-450 has.

Dimensions are such that coil springs appear interchangeable, but the wire gauge (diameter of bar used to form coil) are very different, and are designed according to desired spring rate for given axle weight. Ford specs also show that coil springs are designed so that ride height ends up the same once vehicle is loaded. This is very important with E-Series. Basically, a softer spring compresses more for a given load, so it has to be made longer so loaded length is the same.

If I installed E-450 (5,000-pound front axle rating) coil springs on my van, it would end up jacked up since coil springs wouldn’t compress as much, and also would ride harsher due to stiffness.

sportcoupe · 12-13-2021, 04:41 PM

Interesting to hear the 26" measurement for E-series chassis. I went outside and measured my E350. I got 25.5" front and rear. As suspected without being weighed, I shouldn't be overloaded.

To me, if a shorter replacement rear shackle was available, that would be the simplest way to gain 1" lift.

My shackle is 4.5" center to center.

6inthefamily · 12-13-2021, 05:01 PM

Quote:

Originally Posted by Chance

Ford specifications clearly show about a dozen different coil springs for current E-350 and E-450 Cutaway and Stripped Chassis. Discontinued E-150 and E-250 vans probably had even more spring options due to lighter weight. Even my E-350 Super Duty van has low front axle weight rating so front coils are much softer than your E-450 has.

Dimensions are such that coil springs appear interchangeable, but the wire gauge (diameter of bar used to form coil) are very different, and are designed according to desired spring rate for given axle weight. Ford specs also show that coil springs are designed so that ride height ends up the same once vehicle is loaded. This is very important with E-Series. Basically, a softer spring compresses more for a given load, so it has to be made longer so loaded length is the same.

If I installed E-450 (5,000-pound front axle rating) coil springs on my van, it would end up jacked up since coil springs wouldn’t compress as much, and also would ride harsher due to stiffness.

Hence why I stated, do your own research!

Progressive front springs vs linear are a game changer for the E-450 front suspension. I assume the same would be true for the lighter E-350 with the appropriate spring.

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