My 2018 Roadtrek 210 Dually & suspension updgrades

[valvegod]

Though I would share the outcome pics of my dually rear axle conversion and suspension upgrades. 11.5" American Axle.

Handles like dream at 80 mph one handed going through the mountains. Plenty of power for acceleration up the steep hills. Switched from 3.42 to 3.73 rear gear. (lost less than 2 MPG, but gained tons of power). Suspension 3" higher in front overall with 1" taller diameter tires. 2" higher in back. NO SPARE NEEDED which was a plus and also now the park assist sensors are functional as they are not blocked.

 

[rowiebowie]

You're not the first to do this type of suspension modification, but I admire your work. I like the 210 layout but always thought the rear suspension needed to be widened with dually's to fill out the widened body.

Glad it worked out well and you like the result.
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[User1213]

Dana 60S or 70S differential?

 

[valvegod]

All GM Express vans went to American Axle 2010 and up, maybe even before but cannot verify. I used an 11.5" American Axle which is not available on any of the Express options. Express only used 9.5" and 10.5" even on cut a way duallys 2010-2019.

 

[User1213]

What tires / load rating are you using?

 

[valvegod]

I am running Michelin LTX M/S2 235/80/17 Load E 3085 LBs. single., 2835 LBs Dual @ 80 PSI. So far I ran them 2400 miles 50 PSI front and 50 PSI rears cold. Need to check with GM techline to see if I can have them write a new BCM program to lower the trigger PSI on the TPMS. Right now the rears trigger low at 62 PSI, but do not affect ABS or stabiltrac. Just annoyance.

 

[rowiebowie]

Need to check with GM techline to see if I can have them write a new BCM program to lower the trigger PSI on the TPMS. Right now the rears trigger low at 62 PSI, but do not affect ABS or stabiltrac. Just annoyance.

What does the trigger code look like? Is it the TPMS symbol that illuminates, or does a warning appear in the message center? My '2011 3500 chassis has PSI status, but I have no idea what the trigger level is for front & rear and have never gotten a warning.

I manually check the display daily, but would like the peace of mind to know it will alert me before the tires go flat while on the road. I've never let out air to test, but fronts have been to 49 and rears to 68 without showing a warning. I'd probably want the warning to appear pretty close to those levels as I run 60 front/80 rear as my preferred settings when fully loaded (even though door frame sticker recommends only 50 front).
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[User1213]

Why are you running a lower rated tire on the rear?


With one rear wheel removed & used as a spare the remaining single tire in the rear will be limited to 2835 lbs of certified tire load instead of the rear axle limit which is usually used for single tire selection. (6084 / 2 = 3042 lbs IIRC)

 

[valvegod]

Yes TPMS symbol is the indication of low tire pressure.

 

[valvegod]

Hondo. Not running lower on rear. all 6 tires are the same. The tire companies de-rate the load capacity when running as duals. Look on the sidewall of any tire used on both applications and it will be stamped in the sidewall. Click the link below for an example of load ratings for Michelin truck tires.


https://www.michelintruck.com/refer...s-and-warranties/load-and-inflation-tables/#/

 

[ICkNonDRon]

1) Factory TPMS only supports 4 wheels, which two have you left out, or are you using aftermarket TPMS system?
2) Express van application dual axles never had ABS in them so I doubt there were sensor provisions. I presume the 11.5" axle you used came from a pickup truck. What year and model truck did it come from? Did that axle have speed sensors in it? Is it a direct bolt on in terms of spring perch distance, shock absorber mounts and driveshaft mount?

 

[valvegod]

Yes only 4 TPMS. I am running fronts and inner rears as the outer 2 are easier to see if there is an issue and easier to check pressure, but sensors in all 6 so when I rotate.

Its a custom 11.5" axle all new parts, that I built with custom ABS tone rings etc.

If you have an older model Express without JL4 you could run an express cutaway axle, but not sure if there is room to retro ABS or not. Besides, all the salvage yards wanted more for a used hi millage axle than I could build a new 11.5" for.

 

[rowiebowie]

Yes TPMS symbol is the indication of low tire pressure.

Ok, much appreciated.

Next time I'm at the tire shop I'll drop one front and one rear to see when the alert symbol lights up. It will give me some peace of mind knowing if I'm driving an a tire starts to go flat, I will have some warning.
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[AreCF]

You're not the first to do this type of suspension modification, but I admire your work. I like the 210 layout but always thought the rear suspension needed to be widened with dually's to fill out the widened body.

Glad it worked out well and you like the result.
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The dually conversion looks very nice. What impact does this conversion have on the OCCC of this 210P? Obviously, the dually axle setup weighs more than the original setup. On the other hand, the rear axle weight capacity has to be much higher than the original.

 

[rowiebowie]

The dually conversion looks very nice. What impact does this conversion have on the OCCC of this 210P? Obviously, the dually axle setup weighs more than the original setup. On the other hand, the rear axle weight capacity has to be much higher than the original.

I don't have the conversion, just an admirer of valvegod's work.

I agree with your speculation the load capacity should increase significantly more that the additional weight of his dually conversion. Pretty sure valvegod calculated that at some point.
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