Rear axle width of chassis cap trucks after conversion to SRW

[Oshkosh-P]

Hello,

so as far as i understood it, the Ford and Ram chassis cap trucks 450/550 or 4500/5500 have a wider track in the front (at least at some point in time, apparently not back in the day) to match the width of the dual rear wheel end.

So if you convert such a truck to SRW, will the front end end up beeing wider than the rear, or is that still compensatet but the yet wieder again rear axles on those extra heavy trucks?

And for the F-350 /Ram 3500, if i convert one of those to SRW, will the width then match or the rear still be wider, since the front axle is still narrow?

Kind regards

Marcus

 

[Kingsize24]

Even the SRW 3500 Rams have a wider front axle. I know my 2018 is .6 wider front than rear. It's pretty common. I wouldn't worry about it.

 

[andy_b]

Hello,

so as far as i understood it, the Ford and Ram chassis cap trucks 450/550 or 4500/5500 have a wider track in the front (at least at some point in time, apparently not back in the day) to match the width of the dual rear wheel end.

So if you convert such a truck to SRW, will the front end end up beeing wider than the rear, or is that still compensatet but the yet wieder again rear axles on those extra heavy trucks?

And for the F-350 /Ram 3500, if i convert one of those to SRW, will the width then match or the rear still be wider, since the front axle is still narrow?

Kind regards

Marcus

Generally, if you’re converting a dual-rear wheel truck to singles, the new single wheels are designed to have the same width front to rear. They have offsets and mounting faces such that you mount them oriented one way for the rear and the opposite for the front.

I don’t know why you’d go to the hassle of getting such expensive wheels for a 350/3500, though. If you’re thinking of a 450/550 truck, just get a 550. They are the same size and virtually the same cost for a usable increase in payload.

 

[LikeABoss]

There are only a handful of companies that build the conversion. I have first hand experience with both stazworks setups. They can do a square setup for ram 45/5500 where both front and rear match width at 93” wide. Obviously very positive offset in front, flip and very negative in back.

Or even more positive offset in front and come in at 91” wide. Flip and 95” in back. This setup allows taller or wider tires without rubbing and would recommend despite a slightly different track.

 

[Oshkosh-P]

I mean beeing 0.6 is not that bad of course, but for me a more significant discrepancy would be weird.

Thank you Boss, so 91 would be the minimum for a big RAM CC? I guess similiar for a Ford? And from the comments i guess it will logically be pretty much impossible to get the front an rear of an older F-550 in line right? Since those would have the biggest difference in idth front to rear with the huge rear axle and the "short" Dana Super 60 in the front?

How much wider would a F-350/Ram-3500 end up beeing after a conversion. (I agree that its probably not gonna be worth the hassle, but it's lim pickings over here in terms of trucks anyways)

 

[LikeABoss]

I would say 91” is minimum for ram. I’ve not seen dbl design or buckstop in person but looking at pictures of the wheel lip, they don’t tuck in any further than my narrow Stazworks setup.

Here was my 4500 with the 91 wide setup mounted. The 93” are strapped on the back.

 

[Oshkosh-P]

Wow i love that plattform!

Ok so with 91" beeing the minimum für that weigt class, what is the front and rear minimum width for a F 350/Ram 3500 which used to be DRW?

 

[LikeABoss]

Wow i love that plattform!

Ok so with 91" beeing the minimum für that weigt class, what is the front and rear minimum width for a F 350/Ram 3500 which used to be DRW?

I don’t know the specifics on a 3500 but you will not have the wide front axle, you will have an 8 bolt wheel and a ton more aftermarket options. I may be wrong but if you want a singles, don’t get a 3500 dually and then run singles. Just get a 3500 SRW…. Going to a 45/5500 is the way I went but limits options for super singles and/or keeping a dual wheel setup less than 102” wide. It is very possible but limited to a handful of companies and therefore not inexpensive. My Stazworks duels were 98” wide in back with a 37x11.5 tire. If you want a narrow (for an hd truck), stick to a 25/3500 platform.

 

[Oshkosh-P]

What is WMS? So the the front axle is wieder even before the extra wide 2005+ version was introduced? I mean it kinda makes sense with the space for 4 tires on the rear and all. But if we take the F-350 DRW for example, how much wider would a SRW conversion be compared to the standart SRW F-350?

 

[andy_b]

What is WMS? So the the front axle is wieder even before the extra wide 2005+ version was introduced? I mean it kinda makes sense with the space for 4 tires on the rear and all. But if we take the F-350 DRW for example, how much wider would a SRW conversion be compared to the standart SRW F-350?

WMS = wheel mounting surface. Allows axle widths to be compared at a common reference point (rather than measuring off the wheels, which have variable offset/backspacing).

Could you clarify your design objectives or limitations?

The cabs of 350/3500 series trucks are the same as their bigger brothers. It depends upon the year, make of truck and make of wheel, but a 550/5500 truck would be 3-8" wider, per side, than a 350/3500. I agree w/ @LikeABoss, don't bother converting a DRW F350 to singles.

Sorry for the poor quality but maybe this photo will help visualize it better. These trucks are >20 years apart and not the same make, but the point still stands. The truck on the right is a RAM 5500 converted to singles. The truck on the left is a Ford F350. You can see how much wider the box on the right is - that is how much wider the track width is on a singled DRW 5500 chassis.


I would give the guys at TrailReady a call to discuss your plans. They have a ton of knowledge about it and make a great product.

 

[Oshkosh-P]

Huh 8" is a LOT. The thing is, over here, anything above 2meters (roughly 80") becomes more and more bothersome. Of course there is a bit of wiggle room, but 91 is simply to much, because at that size, i can just get a commercial truck/Unimog.

The only reason why those conversion might be a topic worth discussing is the scarcity of those trucks over here. There is simply a good chance the one truck thats perfect for u in any way will of course not be SRW If it is possible to get a 350 DRW-SRW conversion down to around 83", that would be an option, but i totally agree, going SRW right from the start would be way easier.

But isnt the DRW axle also stronger? Would at least be one upside against the extra cost and hassle...

 

[Oshkosh-P]

Ok so about 85 should be possible then? Well Unimogs are crazy expensive and very slow moving at any gear and most of the European stuff thats isnt an unimog is kinds fragile compared to a F-350

 

[andy_b]

Ok so about 85 should be possible then? Well Unimogs are crazy expensive and very slow moving at any gear and most of the European stuff thats isnt an unimog is kinds fragile compared to a F-350

Why bother with a US-market truck instead of one of the many great Euro platforms? The overall length of a traditional pickup vs cab-over seems like another strike against the pickup platform. In the end, I can't imagine the hassle is worth it but I am admittedly ignorant of the realities of living with Euro cabovers. They sure look cool though!

 

[Oshkosh-P]

Well i guess this is one of those "the grass is always greener on the other side" situations? Dont get me wront in terms of sheer practicality a lot of european solutions would be better, but when you take looks and horsepower into account this becomes a different picture.

Also as i mentioned, some european solutions are much less massive in their components. For example the Iveco Daily 4x4, which would of course be the closest to a class 4/5 US-Truck. The GVW is 7.5 tons so 16.500lbs. But the C-Channel frame is only 185x70x5mm. The Ford base C-Channel without the xtra layers for the 19.500lbs version is already 190x70x8mm, so a bit larger but more importantly more then 50% thicker! The RAM frame is 7.7mm in thickness and is about 220 in height, with some areas even reaching 300mm. Of course there is also quality of steel, amount and design of crossmembers etc. but with these big differences there will also be a difference in strenght. Again you could always go Unimog, where some version are even smaller while beeing stronger (The U140 for example is 82" in width and features a 4ton front axle) but those are really slow most of the tiime.

Also a F-350/Ram 3500 is sitting at a comfortable position in terms of weight, in that i could always take the cab off and rate it down as a car in terms of weight limit (3.5tons) especially with the lighter gas engine. This way i could use it as a camper for a couple of weeks and drive it full throttle on the autobahn the rest of the year. Reason is that as a truck above 3.5tons (metric) you are limitet to 80km/h (50mph) while having no speed limit as a car. This again would also be possible with some of the Unimogs, but there top speed is technically around 90km/h (56mph) anyways so does not matter. I know people driving their Rams at around 100mph regulary, thats not possible with most european solutions.

And also the looks, as impractical as a long snout might be, it beats a cap over in terms of looks any day of the year and twice on sunday.

 

[andy_b]

I suppose the grass is indeed always greener. You know your travel needs and objectives better than I, but wouldn't the extra length and poor turning circle of American pickups be as much of an issue as width in many parts of Europe? Cabovers do have limitations (no Euro manufacturer makes a cabover interior as nice as higher trim US trucks) but their overall packaging seems like a better fit for your needs.