Making a B+ or C Class more capable.

pnichols

Member
For the 2005 model year of our Class C's E450 cutaway van chassis it differed from the E350 cutaway chassis at least as follows:

- Front and rear torsion bars. (E350 had only a rear one).
- Larger diameter drive shaft, hence less chance for any drive shaft vibration under load.
- Larger swept area for brakes (so new brake pads required less often for any given vehicle weight, at ~85K miles my front pads are still original).
- Hydraulically boosted power brakes instead of vacuum boosted power brakes.
- Wider rear dually stance for improved side-to-side (lateral) stability on curves, in high cross-winds, and when getting passed by trucks.
- Higher rear differential ratio (4.56:1 instead of E350's 4.10:1) for improved hill climbing, offroad crawling, towing, and less transmission internal heat generation due to less torque converter slippage under load.
- More weight carrying capacity so we can load it anyway we want with no concerns for (in our small Class C) total vehicle weight
- Way less, if any, front versus rear height difference due to how we might load the front versus the rear.
- No stabilized jacks required to eliminate coach movement when walking around inside.
- Thicker steel used in the base chassis frame so there will be less chance of frame twist when traversing rough or rutted roads.

We basically wanted chassis overkill when we bought our 24 ft. Class C on the optional E450 chassis. Most of the advantages listed above of course go away if a large(er) Class C is built on the E450 chassis ... because "chassis overkill" no longer will apply as much or at all.

Basically, chassis overkill provides a better K.I.S.S. approach because you're using a heavy duty tool in a light duty way.
 
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Photobug

Well-known member
For the 2005 model year of our Class C's E450 cutaway van chassis it differed from the E350 cutaway chassis at least as follows:

- Higher rear differential ratio (4.56:1 instead of E350's 4.12:1) for improved hill climbing, offroad crawling, towing, and less transmission internal heat generation due to less torque converter slippage under load.


We basically wanted chassis overkill when we bought our 24 ft. Class C on the optional E450 chassis.

Sounds like some very good upgrades for an RV intended for offroad use. Did you buy it new?

Any suggestions on how to determine what my differential ratio is?
 

pnichols

Member
Sounds like some very good upgrades for an RV intended for offroad use. Did you buy it new?

Any suggestions on how to determine what my differential ratio is?

Yes, we bought our 2005 new ... after looking for a long time to find just the right small Class C that happened to be built on an E450 cutaway chassis - instead of the E350 cutaway chassis usually used for small motorhomes.

Note above in my post #92 that I've had to correct my post -> back in 2005 (and I think still today) the E350 rear differential ratio was 4:10.1 ... NOT 4:12.1.

I think that it's very difficult anymore for the general public to locate detailed specifications on the Ford E-Series chassis (even though Ford still offers it in a cutaway version to RV builders). Years ago I was able to easily locate extensive specs (i.e. such as info on frame construction) for the 2005 E450 cutaway chassis under our Class C.

Here's a typical link of about all that can be found nowadays on E-Series chassis specifications: https://www.ford-trucks.com/specs/
 

Bikersmurf

Expedition Leader
Try finding specs for a ‘97... even harder. Or parts interchange. My 12/96 now has a 2001 master and booster for improved braking. It was a direct bolt in, however it did require new brake lines to cross over. I had them custom made, but they could be the same as a 2001 for all I know.

I guess our rigs are just becoming obsolete. ;)
 
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Buddha.

Finally in expo white.
Sounds like some very good upgrades for an RV intended for offroad use. Did you buy it new?

Any suggestions on how to determine what my differential ratio is?
I think the fords often come with a tag on the diff. 4 10 would be an open 410. 4L10 would be a limited slip.
Or look up the code on the door jam sticker where it says “axle”.

 
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Photobug

Well-known member
So I ended up with a Born Free 22. I have been out 4 times in it. It has been awesome. Because of its purchase cost and my need to keep it under budget. I want to do the following with it for short term upgrades.

Locking differential.
2" lift blocks.
Should I add a spring also?

I am hoping or some advice on choosing these. The Axle is a Dana 70 HD. I have found these that look like they may work. Which model should I look for?
Where should I look for lift blocks?


20210627_211032.jpg
 

rruff

Explorer
Locking differential.
2" lift blocks.
Should I add a spring also?

I'd recommend the lift first. From a brief search it looks like Moog front springs (and alignment cams) and 2" blocks on the rear will get you in the ballpark, and be cheap. Swap the block for springs + new shocks + better tires when you can afford it. Then look at lockers. Get a good pump (or two) and air way down for sand if you think you might get stuck.
 

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