Bed Rail Clearance (trying to maximize clearance between truck bed rails and RV)

[atom ant]

Originally Posted by bergeman

I see what your trying to say. I hooked my GMC up and didn't think twice. Sure I have a little damage now. The damage to the metal will be covered up when I get a new plastic rail for the truck. I would still rather have the GMC then a ford.

Sorry you had damage, but couldn't let this comment go without some kind of response

Originally Posted by bergeman

Let me say that you do have absolute best truck available, bar none.

[bergeman]

Brad, wrote that comment with you in mind.

I ended up on a dead end street, apartment complex in denver. The fact that I was able to turn around with this rig and get out of there, the damage was insignificant. I was happy I didn't take 10 cars with me. All I can say, I need a bigger gas tank.

[atom ant]

I understand Scott - I did a little site seeing at a Nebraska State Park and the ranger said "no problem" about turning around in the parking lot at the observation point. Wrong! We had to wait for everyone to leave and I ripped up pavement in my 90 degree turn. It looked like a U.S. Army tank retriever just turned around in there

I did twist a spring so the leaves are not aligned. I still need to fix that.

[mhs4771]

"Could this issue also be fixed by raising the hitch a notch?"
Probably not, what would need to be raised is the Pin Box itself
"Do you have the GMC dually? If so what hitch and king pin assembly do you have? Also, how much clearance do you have?"
Not a GMC, but the Chevy version, with a 20K Reese and have 8 to 9 inches clearance, but we are just a tad nose high, but because of the bed rail issue I don't want to lower the hitch, really need to raise the King Pin box, but just don't have the tools here if Florida to do the job, Maybe in the summer when we're back north I'll thing about trying.

[Mike&Pam]

Hi All,


Thanks so much for all of the responses. I appreciate the feedback.


Sounds like when adjusting the fifth wheel hitch and the position of the king pin, there is compromise in many cases.


If you want more bed rail clearance, you have to compromise being "nose high" and if you want to tow level, you have to compromise bed rail clearance. The trick is to "maximize" both parameters (i.e. maximize bed rail clearance and keep the trailer as level as possible) the best you can.


From my understanding so far, I think that if you are too nose high, you will put more weight on the trailer axles and suspension and cause more wear & tear.


Having said that, what is a good compromise for maximum bed rail clearance and being nose high? Furthermore, how much "nose high" can you be and not do any damage to the trailer axles and suspension?


Say you had a couple reasonable choices...


1) Have 8+" bed rail clearance but be an inch or two nose high.


2) Have < 8" bed rail clearance and be perfectly level but have occasions when pulling into a gas station, there is some rubbing going on.


Me personally, assuming that being only an inch or two nose high doesn't cause damage on the trailer axles & suspension, I would choose choice #1.


What do you all think?


Mike

[markw]

You might be over thinking this right now. Get the hitch that you want installed, hook up and adjust from there.It might be nose high at 7'' or level and 9''.

Mark

[TnB]

I have a Silverado with a Curt 24K hitch. I previously had a GMC with a Reese hitch. Both trailers had the Tri-Glide king pin. Both had problems with clearance problems when making 45 degree or sharper turns.

My solution was to move the electrical box from outside of the rear of the king pin, to inside of the kingpin box. This gives me more room behind the pin for tight turns.

[Ford truck guy]

I was running around 9" of bed clearance with the nose about 4" high.. By raising the pin box 1 set of holes (1-1/2" on centers) I was able to achieve 7-1/2" bed clearance and almost level conditions..

With the placement of the axles , as you lower the front , you will also raise the rear a bit ( not exactly an inch for an inch).. Now I have to go out and do more towing to assure I don't have an issue with bed clearance... At least that's my excuse to my wife to go !

[Mike&Pam]

Tom,
After moving the electrical box, can you turn now and not worry about contact?


Mark,
I am very tenacious and extremely detailed oriented and am trying to be as knowledgeable as I can be. Given the fact that I know "very little" about towing fifth wheels, the shop guy who finally installs the hitch and does all of the adjustments could probably tell me just about anything and I would believe it because I am not in a place to question what he did. As a matter of fact, I have had comments from the dealership indicating that as long as you have 6" clearance, there are no issues whatsoever. Well.... being on this site definitely proves otherwise. I have also done searches on other sites and found that most folk want more than 6" clearance. Therefore, my goal is to draw from the knowledge that folk on this site have because I have a feeling that just about everyone on this site knows what they are talking about. Obviously, there will be matters of opinion but when it comes to the basics (which I know nothing about), I would assume that everyone here will know a whole lot about that. Having said that, you mentioned in past comments that you lowered your hitch and that you are still running a tad bit nose high. If you don't mind me asking, how much nose high? I am assuming that you are ok w/ that amount. Just trying to get a feel for what amount "nose high" is acceptable.


-Mike

[rob_fla]

Since our 38FL only has approx. 3000 lbs. of pin weight and our GMC does not squat very much under load and does not sit solid on the overload springs, I was hitting the overload springs and getting a lot of bounce on entry and exit to bridges and such.
I installed lowering shackles on our GMC to reduce the distance between the overloads and the overload spring brackets.
Wound up with two positives, one no more bounce when hitting the bridge entry and exits due to more weight on the overloads and now our truck sits level when hooked up to our 38FL so I had to raise our Curt 24Q one more position giving me better clearance.
Now the Truck and the Trailer are both level and the ride is much better.

[markw]

Originally Posted by Mike&Pam

Tom,
After moving the electrical box, can you turn now and not worry about contact?


Mark,
I am very tenacious and extremely detailed oriented and am trying to be as knowledgeable as I can be. Given the fact that I know "very little" about towing fifth wheels, the shop guy who finally installs the hitch and does all of the adjustments could probably tell me just about anything and I would believe it because I am not in a place to question what he did. As a matter of fact, I have had comments from the dealership indicating that as long as you have 6" clearance, there are no issues whatsoever. Well.... being on this site definitely proves otherwise. I have also done searches on other sites and found that most folk want more than 6" clearance. Therefore, my goal is to draw from the knowledge that folk on this site have because I have a feeling that just about everyone on this site knows what they are talking about. Obviously, there will be matters of opinion but when it comes to the basics (which I know nothing about), I would assume that everyone here will know a whole lot about that. Having said that, you mentioned in past comments that you lowered your hitch and that you are still running a tad bit nose high. If you don't mind me asking, how much nose high? I am assuming that you are ok w/ that amount. Just trying to get a feel for what amount "nose high" is acceptable.


-Mike

I understand what you're saying but until your hooked up and fully loaded, you're mostly guessing at it. The air ride pin box will will give more clearance than without. You probably won't need a hitch the goes very high. More likely you'll need lower settings. I have my Pullrite two holes lower after installing my Flexair box. IIRC I'm still well over 7".maybe 8.

Mark

[bergeman]

Could someone explain "Nose High" and how I would recognize it. I'm thinking that the bottom of the trailer should be level with the ground. When someone says they are 2 inches high, that means the front part of the trailer frame is 2 inches higher then the rear frame.

[GA1817]

Keep in mind that the air bag on the trail air pin box can make a big difference as well. Letting just a little air out can drop that nose quickly to level the RW.

[xtasee]

Originally Posted by TnB

I have a Silverado with a Curt 24K hitch. I previously had a GMC with a Reese hitch. Both trailers had the Tri-Glide king pin. Both had problems with clearance problems when making 45 degree or sharper turns.

My solution was to move the electrical box from outside of the rear of the king pin, to inside of the kingpin box. This gives me more room behind the pin for tight turns.

I think you mentioned this before on another thread. Where exactly did you mount it inside the box? Picture? The first thing I want to do (if my new unit ever gets here) is to relocate that box. It looks like you could screw it to the floor above the pin box or to the side in the metal. I would like to make sure there is no interference with the travel of the Tri-Glide

[RCAircraft]

I

Originally Posted by Mike&Pam

One more question for mhs4771.

Do you have the GMC dually? If so what hitch and king pin assembly do you have? Also, how much clearance do you have? Just curious also if you just live with that issue with tight turns and pin box corners scratching or did you trim off some of the corners (assuming you have a gmc)? Perhaps this issue is rare or can be avoided?

Mike

Congratulations on your new rig
I have a very similar truck and hitch as yours. The king pin is a TrailAir Ride 18 K mated to a Reese Elite 25K removable hitch with Reese under belly rails. The hitch height is adjusted to give clearance between the Retraxpro 4011 sliding bed cover and the hitch release handle. The clearance to the bed rails on the 2016 Silverado High Country 3500 DWD long bed measures about 10-11 inches however I will be road testing next week to get better clearance dimension with everything loaded. I hope to have at least ten inches to the bed rails as bridge joints, pot holes and tight turning really close the gap quickly. My previous 2012 Ford 350 Lariat SWD short bed had 12 inches bed rail clearance and still I lightly nicked the protected bed rail backing into a tight spot. The rail clearance along the tail gate has been more concern for me especially with extreme dips between the truck and trailer. I chose the 25K Reese rating as bridge joints, pot holes, rail crossings and stop/go traffic really hammer the hitch. As noted by others the amount of air (air pressure) in the pin air bag does impact bed rail clearance. I usually have about 110 PSI inflation pressure.
Wishing you many years of happy RV'ING.

[YogiBear]

My 2013 Ford F-350 6.7 Powerstroke, backed into the Redwood 39 MB and went down the road no problems at all clearance or level of the RW.
Using the trail air glide ride pin box and away we go.
Love my Ford and RW.

[travelin' texans]

Those air bags are only rated to 100psi! At that pressure it would most likely negate most all of the jarring/banging it was designed to minimize. On mine anything over 70psi is way too stiff, I don't have 10/12" of clearance either & never had a problem.

[RCAircraft]

100 Psi on mine will not lift the pin to the designated line. My manual is showing 110 PSI max. I will double check on though. Thanks.

[hoosierguy]

Originally Posted by travelin' texans

Those air bags are only rated to 100psi! At that pressure it would most likely negate most all of the jarring/banging it was designed to minimize. On mine anything over 70psi is way too stiff, I don't have 10/12" of clearance either & never had a problem.

Danny..........I agree. I run the Tri-Glide air bag at 65 to 75 psi depending on load.

[travelin' texans]

I don't pay any attention to their line on the shock as that makes it too stiff for mine. I've experimented with several pressures & found 70psi before hooking up is the best ride for my setup. If your having to run max air pressure for bed clearance I would be adjusting the hitch or king pin up/down & let some air out of the bag & see if your ride doesn't improve greatly.