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Proper Tire Pressures on 5th Wheel - 23ML

RockDr896

Prominent Member
Appreciate the reply and questions. I did measure the 5th wheel twice to get the left to right weights (just didn't show it on the first picture as I didn't want to confuse people). 1st weigh had both left and right wheels on the platform. 2nd weigh had only the right wheels on the platform. I calculated the difference to determine the left wheel weights on the trailer. You can see that the left side weight 360 lbs more than the right side.

The left side had the refrigerator, oven, microwave and the slide so this makes sense that it is heavier. I'm guessing that Alliance is using tires / wheels / axles that are rated high enough that differences in weight between left / right due to construction / loading and differences between front trailer axle and rear trailer axle due to hitch height / loading don't really matter. Given the feedback everyone has provided, I think I'll continue to run with pressures between 75 and 80 psi. Thanks!!!
Well you really did your homework!! Thanks for sharing your weights left to right! I think that is close enough for RV engineering, although the vehicle manufacturer is better balanced....until a 300lb driver gets in the truck with his 98 lb wife...LOL
 

M and E

Prominent Member
You are correct that I'm running a little nose high but there is a reason. What may not be obvious from the picture is that this RAM 2500 has RAM boxes which makes the bed narrower. I uncomfortable adjusting the hitch / pin box to lower the front because the clearance is minimal on the inside of the bed due to it being narrower (not the height over the bed rail). Wish I had options here. Appreciate the suggestions.
That is a good looking combo! Delmonico Red?

Like @BryanValRox said, I'd really consider trying to change that nose high attitude. It almost looks like the rear axle is loaded and ready to rebound. I know you said you were uncomfortable with that idea but maybe take a few measurements and see if it might work. Good intentions only.
 

Flyer32RLS

Well-known member
After looking at your set up, it looks like you have more than enough clearance on the truck rails to lower it a bit and put some more weight on the front axle of the RV. I'm guess you have 8-9 inches clearance. 6-7 is enough unless you go cross country.
 

RockDr896

Prominent Member
That is a good looking combo! Delmonico Red?

Like @BryanValRox said, I'd really consider trying to change that nose high attitude. It almost looks like the rear axle is loaded and ready to rebound. I know you said you were uncomfortable with that idea but maybe take a few measurements and see if it might work. Good intentions only.
I agree with Flyer and M&E....the clearance on the rear tire fender compared to the front, is noticeably different. The clearance to the truck bed, seems to have plenty of clearance for adjustment. I looked back at your axle weights and I did not see if you paid to check the 5th wheel axles individually. Normally, that would require the state police to pull out their individual scales and not an option at CAT Scales, that I am aware of. However, the eyes don't lie! Let us know how it pulls, if you stay the course! Enjoy the rig...
 

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Slats

Member
Understand, thanks for sharing.
You do you, but I guess I am having trouble understanding how lowering the nose by 1 hole would alter the swinging radius of the hitch when turning and risking contact with the ram boxes. Maybe there is just something I can ‘t see or am to hard headed to understand (most likely the later)😂. Enjoy the new rig!!
Yes. I had the same issue understanding the clearance issue until it was setup at General RV and saw it with my own eyes. I have a Pullrite auto-sliding hitch that is attached to rails in the bed of the truck. I was looking at lowering the nose of the RV by 1 hole on the Curt Rotaflex pin box to get the RV more level.

Obviously the radius of swing doesn't change but (#1) raising the hitch by 1 hole (1 to 2 inches) results (#2) in lowering the corner metal plates on the RV the Curt hitch attached to by 1 to 2 inches (see picture). This leaves me with very little clearance between that lower corner of those plates that stick out below the hitch (see yellow box) and the inside of the bed (remember my RAM 2500 has ramboxes where the width of the bed is 50 inches instead of 66 inches.) The clearance is only about an inch when on level ground and making a tight turn. On unlevel ground where the RV is not on the same plane as the truck, the clearnance gets even less. I'm not willing to risk having a 'collision' between the corner of the metal plates and the inside of the truck bed. Ramboxes make it very difficult to get a 5th wheel hitch setup properly due to clearance issues. I do think I'll go across a CAT scale again and put the RV front axle on one scale and the RV rear axle on the rear scale to see what difference in weight exists before I decide what to do next.

By the way, I found a link to Grand Design website where someone had clearance issues with their Rotaflex pin box and their bed cover rail. Note - this is on a regular width bed with the bed rail attachment that slightly narrows the bed by ~2 inches on each side.
 

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BryanValRox

Elite Member
Yes. I had the same issue understanding the clearance issue until it was setup at General RV and saw it with my own eyes. I have a Pullrite auto-sliding hitch that is attached to rails in the bed of the truck. I was looking at lowering the nose of the RV by 1 hole on the Curt Rotaflex pin box to get the RV more level.

Obviously the radius of swing doesn't change but (#1) raising the hitch by 1 hole (1 to 2 inches) results (#2) in lowering the corner metal plates on the RV the Curt hitch attached to by 1 to 2 inches (see picture). This leaves me with very little clearance between that lower corner of those plates that stick out below the hitch (see yellow box) and the inside of the bed (remember my RAM 2500 has ramboxes where the width of the bed is 50 inches instead of 66 inches.) The clearance is only about an inch when on level ground and making a tight turn. On unlevel ground where the RV is not on the same plane as the truck, the clearnance gets even less. I'm not willing to risk having a 'collision' between the corner of the metal plates and the inside of the truck bed. Ramboxes make it very difficult to get a 5th wheel hitch setup properly due to clearance issues. I do think I'll go across a CAT scale again and put the RV front axle on one scale and the RV rear axle on the rear scale to see what difference in weight exists before I decide what to do next.

By the way, I found a link to Grand Design website where someone had clearance issues with their Rotaflex pin box and their bed cover rail. Note - this is on a regular width bed with the bed rail attachment that slightly narrows the bed by ~2 inches on each side.
I certainly respect your decisions and certainly hope that you find a solution that you are comfortable with.
Enjoy the new rig!
 

Slats

Member
Thanks Bryan. If / when I need / want to upgrade my truck, I'll think twice about getting RAM Boxes. While they are are nice for storage, the narrower width of the bed can cause issues / limitation when it comes to towing a 5th wheel. I very much appreciate everyone's thoughtful responses.
 

M and E

Prominent Member
Thanks Bryan. If / when I need / want to upgrade my truck, I'll think twice about getting RAM Boxes. While they are are nice for storage, the narrower width of the bed can cause issues / limitation when it comes to towing a 5th wheel. I very much appreciate everyone's thoughtful responses.
I loved Ram boxes on my Ram but that was with a bumper pull. Hated losing them! The convenience of access for just diesel additives alone makes them worth it.
 
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