C4500 Ambulance Camper

cjken

Explorer
Got the new valve in.
May do the other side as well.
852ff3e998561dd48f8b323f8a331fb1.jpg


Air ride problems solved. For now.
 

cjken

Explorer
Fundamentally the problem in converting a DWR to SRW is that on the front the wheel mounts with an offset of ~+180-200mm. The duals on the rear of course have a net offset of 0mm. A “proper” rear SRW wheel will have an offset of 0mm, but front still quite positive.
A choice: 2 sets of wheels, with a ??? spare, or unequal tracks, or excessive stress on front or rear wheel bearings. The only really good solution is a (rear?) axle swap with proper width so that equal offset wheels will give nearly equal tracks and optimize rear wheel bearing stress, in most cases. And brake protection.
AFAIK, none of the USA medium to HD mfgs offer SRW as a factory option.
Apologies if I am repeating the obvious.

Yes Charlie,
I was luck with my E350 Ambo. Just had to source SRW front hubs and everything worked out. This MDT not so much.
I’m intrigued by those MXT rims, but they seem nearly impossible to get. The MXT is probably the only SRW MDT I can think of.
My friend had wide 22.5’s on his CXT, but took them off because he said it ride like a dump truck. However, some seem to like the wide 22.5 setup in the C4500/5500. Maybe he was running them too hard, but the intended load rating on those is so far above our trucks.
 

mog

Kodiak Buckaroo
this could be a possibility

385/65 22.5 on Alcoa EIGHT LUG rims

Yup. There are some 'odd balls' out there. All the Alcoa 8x275mm super singles are listed as 'obsolete', but they did make some, and they are floating around.
I have a pair of Alcoa PN 823400 which are 12.25 x 22.5 with a 0.56" offset. You might want to check if that 6.25" offset will work on the C4500/5500s.
 

motorman

Active member
mine is a 10 lug so they are all yours

im probably going to be 'forced' to purchase new wheels as i have never seen more than a pair for sale 12.25 x 22.5 10 lug

probably save around 300 lbs total, have singles and pick up some mpg by reducing the rpm at cruising speed . . . not to mention a couple inches of ground clearance
 

Brewdiak

kodiak conversionator
Update on my tires/wheels- the tires are out of round... I drove it finally yesterday to burnish the brakes, that part went fine but the truck is still basically undriveable above 40. I had considered trying to grind the tires true myself, but fact is the move to singles has cost me 2+ years and a lot of time money and effort. So I’m done. I’m going to get 255/70r22.5 I think and call it a day. I may see if I can find a wider front tire that would match the diameter and get a pair of Alcoa that are 8.25” but not sure that is possible. Goodyear caused me a lot of trouble and money with their egg shaped tires ?
 

java

Expedition Leader
Update on my tires/wheels- the tires are out of round... I drove it finally yesterday to burnish the brakes, that part went fine but the truck is still basically undriveable above 40. I had considered trying to grind the tires true myself, but fact is the move to singles has cost me 2+ years and a lot of time money and effort. So I’m done. I’m going to get 255/70r22.5 I think and call it a day. I may see if I can find a wider front tire that would match the diameter and get a pair of Alcoa that are 8.25” but not sure that is possible. Goodyear caused me a lot of trouble and money with their egg shaped tires
************

Sent from my SM-G973U using Tapatalk
 

shortbus4x4

Expedition Leader
Kind of like running old bias ply tires, you had to let them "warm up" for a few miles before they were round. It had been years since I had driven a truck with them but I brought one home a few years ago that had bias ply tires and it took over 5 miles before the tires lost their flat spots.
 

cjken

Explorer
Sorry to hear that the tires are giving you such drama. The truck itself is coming along awesome.

If you are planning to tow a Jeep, which I think you said, maybe you can run the dually and just take the Jeep to the more extreme places.
We have tons of beach sand up here. Not sure I can make the duals work, but am going to take baby steps figuring it out.
 

cjken

Explorer
Cool! Jeff at 1st Attack was easy to work with. Will report back. I was thinking similar on bed. Saw where someone just used barn door track for the verts. Need to find some low profile surface mount pulleys for thin cables.


Sent from my iPhone using Tapatalk

Hey Korey, any updates on the rims and tires? Really curious as to how the MPT-81’s are working out on your rig.
 

Brewdiak

kodiak conversionator
so...if i were just starting my build I'd go with what you did Korey - 1st attack and mpt81's

i'm not done with singles...but for now i'm going to run it on the 22.5's and finally go find places to sleep in it. i'll revisit the tires and wheels after I put some miles on these, for reference if anyone else is in the tire/wheel hell now or in the future I put the style/size below. Initially it was REALLY hard to look at it on these skinny tires, i've gotten more used to it especially after I finally did about a 200 mile road test and found it to be 'acceptable'. I still do not like how close the inside dual tire is to the rear airbags...i figure it's unlikley a rock or something could get kicked up and wedge or slice the bag....but with only 1/2" it wouldn't take much to find its way in there even for a second.

rear: Sailun S753 EFT 255/70R-22.5
front: Sailun S637 255/70R-22.5
wheels - 4 alcoa / 2 steel *** with rear air bags on this rig I had to mount the rear alcoa inside and the steel on the outside due to different offset, that gives only about 1/2" tire to bag clearance
 

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