Lower my truck's rear end or raise up the 5th wheel camper?

DuluthCamper · 03-30-2021, 01:30 PM

In my first-timer inexperience, in 2020 I bought a 2010 FR Rockford Signature Ultra Lite 5th wheel (and we LOVE it!), and a 2016 Chevy 2500 HD Diesel to tow it.

The trailer dealer installed the 5th wheel hitch in the truck without questions, and the truck hauls the trailer very nicely.

My concern is the clearance between the top of the rear of the pickup box and the underside of the 5th wheel overhang. It's about 2.5", and that's not enough to manage small gullies or big pot holes, or campsites that have to be backed up a fairly steep hill. The underside of the camper's overhang impacts the truck's rear end at the truck corners & tail gate.

I've seen a dozen different solutions offered / recommended. FR's factory rep says not to do anything to the trailer height. Chevrolet says don't modify the truck in any way. I understand; they're concerned about safety, and haven't tested with the modifications I'd like to make.

Short of buying a different truck, what experiences do 5th-wheel-owners in this forum have to share?

Things I've been advised to try include:
* Smaller truck tires in the rear, or all the way around
* Put on bigger trailer tires or wheels & tires
* Put in a Fifth wheel hitch lift kit. I'm not excited about raising the front of the trailer in any way--it's already riding front-end-high. I'd rather get it riding level on all four tires.
* Install a "drop shackle" kit on the rear springs of the truck to lower it
* Install a lift kit on the camper to raise it (these are torsion axles--doesn't seem possible to put a lift kit on them, but I'm an amateur at it. I can't flip the springs to get the trailer to ride higher. Is this possible with torsion spring axles on the trailer?)
* "De-Arch" the truck's rear springs to lower them. I Googled it, it's a thing. A local business has a big press that can take some of the arch out of truck springs. They can also re-arch them if a person wants the "factory condition" back, without having to buy new springs.

If you've been in this position, what solution did you use to get the trailer to ride level, and have more clearance between the 5th wheel overhang and the top of the rear of the truck box?

phillyg · 03-31-2021, 08:24 AM

Yeah, 2.5" is way too little clearance. The recommendation is 5-7". I don't see you can increase it much with smaller wheels/tires that can still carry the required load, leaving spring mods or increasing trailer height. I can't opine about the springs. However, the normal method of "flipping" the axles might do it. Flipping is a misnomer, as it really means relocating the axles below the spring perch rather than above. The best method I've seen is to have thick-walled rectangular box steel, about 6' long, welded to the underside of the frame, and the spring mounts welded to the box steel (make sure alignment is done). Depending on the height, you might not have to flip the axles. I suspect the RV mfgr. advises against it because it raises the center of gravity, but......

Brother Les · 03-31-2021, 09:15 AM

Very sad when one has to do 'aftermarket' mods in order to have the correct height on your truck bed/5thwheel combo, to keep from doing damage (and damage will occur if nothing is done). Many 5-vers have come before you with this dilemma and you will get better advice from them than from me. I am interested on the GOOD advice that will come. Please think, Safety, First and Always. Never compromise on a short term and shabby fix just to get by. Too much is at stake for a not so good compromise. I have seen some 5-vers going down the road (fast) and the front end of the camper is a foot or so higher than the back.... NOT a good idea.....

**Bama Rambler** · 03-31-2021, 01:29 PM

The good news is that they make a lowering kit for that truck. It lowers the front 2" and the rear 3", so that would help some. At least it would allow you to increase the distance between the bed rails and overhang and not change the current RV levelness.

DuluthCamper · 03-31-2021, 04:19 PM

Thanks for the suggestion! I haven't had damage from the low clearance due to road conditions yet, but I worry about it. And I've gotten the back of the truck uncomfortably close to the overhang's bottom when backing the camper up a steep driveway onto a campsite that was level. We'll see what other options appear.

Smooth roads your way!

Quote:

Originally Posted by Bama Rambler

The good news is that they make a lowering kit for that truck. It lowers the front 2" and the rear 3", so that would help some. At least it would allow you to increase the distance between the bed rails and overhang and not change the current RV levelness.

DuluthCamper · 03-31-2021, 04:22 PM

Thank you for your thoughts.

In my trailer's case, flipping the axle springs isn't an option because it's a torsion axle. The trailer's already riding on top of it as high as it can.

Similarly, installing an extension "spacer" box between the frame and axle, or between the camper and the frame, is also not an option due to design.

But I appreciate you thinking about the problem and offering some ideas.

Smooth roads to you!

Quote:

Originally Posted by phillyg

Yeah, 2.5" is way too little clearance. The recommendation is 5-7". I don't see you can increase it much with smaller wheels/tires that can still carry the required load, leaving spring mods or increasing trailer height. I can't opine about the springs. However, the normal method of "flipping" the axles might do it. Flipping is a misnomer, as it really means relocating the axles below the spring perch rather than above. The best method I've seen is to have thick-walled rectangular box steel, about 6' long, welded to the underside of the frame, and the spring mounts welded to the box steel (make sure alignment is done). Depending on the height, you might not have to flip the axles. I suspect the RV mfgr. advises against it because it raises the center of gravity, but......

wanderingbob · 03-31-2021, 05:08 PM

A lift kit for torsion axles is fairly common , I bought mine for less than $200 from E-Trailer . Fit perfect , took about two hours for the first axle then 30 minutes for the second !

JJaxon · 03-31-2021, 09:41 PM

Clearances between the truck bedrail and the bottom of the 5th wheel over the bed. The only way to increase that distance is to increase the hitch height in the bed. Lowering the truck brings the hitch with it and the 5r too, so nothing gained. Identify the make and model of your hitch, and read the manual on how to raise the hitch plate, raising the front of the camper. Flipping axles raises the rear of the trailer, not the front. Expand the hitch height gives you more clearance. Dealers aren't always your best resource for in use adjustments.

Thomas ho · 03-31-2021, 09:58 PM

you could go with a b and w turnover ball with a anderson ranch hitch. snout is adjustable up and down. you can put on the ranch hitch yourself its easy. ball by a ranch supply.

bplantcjf · 03-31-2021, 10:01 PM

I had the same issue. Got a 3" lift from the axle manufacture. Same torsion axles. Same set up as you with a Signature ultralight and Chevy 2500 duramax. 5th wheel rides level now but still only about 5 inches clearance but haven't hit with about 8,000 miles. Had the lift installed at a frame and axle shop that did an alignment after putting it on.

BMullins46 · 03-31-2021, 10:09 PM

Funny thing nobody as suggested adjusting the hitch height. My B&W has a couple holes on either side so the hitch height can be adjusted. OP didn't say what hitch he has so that may be an option. Also my pin box has adjustment holes. In either case neither would be considered a modification to either vehicle.

AnderGlamper · 03-31-2021, 10:20 PM

I’m new to towing a 5th wheel, I had an Anderson Ultimate hitch installed to my ‘08 Chevy 2500HD Duramax and it gives me that clearance and an ability to adjust the height if needed. You might want to consider this before modification of your truck or trailer. It might actually be the cheaper solution.

DouglasReid · 04-01-2021, 05:33 AM

Quote:

Originally Posted by JJaxon

Clearances between the truck bedrail and the bottom of the 5th wheel over the bed. The only way to increase that distance is to increase the hitch height in the bed. Lowering the truck brings the hitch with it and the 5r too, so nothing gained. Identify the make and model of your hitch, and read the manual on how to raise the hitch plate, raising the front of the camper. Flipping axles raises the rear of the trailer, not the front. Expand the hitch height gives you more clearance. Dealers aren't always your best resource for in use adjustments.

In addition to raising the hitch in the bed of the truck the pin box on the 5er can be lowered to gain overhang/truck bed clearance too.

I think your first concern should be the clearance. After you tet that issue solved then leveling the camper while connected to the truck should be the next issue to work on.

The dealer threw it together to get it connected and you off the lot while they ran to the bank with their loot. Now it is up to you to get it right.

JJaxon · 04-01-2021, 06:55 AM

Post #8 did mention hitch height. That is the only way he can gain clearance

DouglasReid · 04-01-2021, 07:10 AM

Quote:

Originally Posted by JJaxon

Post #8 did mention hitch height. That is the only way he can gain clearance

NOT correct, lowering the pin box where it attaches to the 5er frame has the same effect of increasing the bed clearance as raising the hitch height.

If the difference in height between the overhang bottom and the hitch pin is right now 12" and you lower the pinbox so that distance is now 14" you haveincreased the bed clearance by that extra 2"

Think about it!

DuluthCamper · 04-01-2021, 02:33 PM

Thank you, Wandering Bob. I did reach out to E-Trailer prior to posting my question here. I like their staff & technical abilities.

For now, I'm concentrating on a way of keeping the trailer as it is, for a few reasons:

1. I don't need any more height on it; clearance below lower bridges is a concern, and even two more inches are inches I'm not yet willing to give up.

2. The trailer already rides front-high. I'm not liking the unequal distribution of weight on it. So lowering the truck seems to be the best solution to get the trailer to ride level.

And since the trailer's riding on the king pin centered over the rear axle, lowering that axle will also result in an increased clearance between the tailgate's top and the underside of the camper's overhang. Probably not as much as I'd like, but still, it's something.

Please keep me in mind if you have other advice. I truly appreciate your input!

Rick

Quote:

Originally Posted by wanderingbob

A lift kit for torsion axles is fairly common , I bought mine for less than $200 from E-Trailer . Fit perfect , took about two hours for the first axle then 30 minutes for the second !

DuluthCamper · 04-01-2021, 03:05 PM

Thank you so much for the advice, John!

I'm going to keep looking a bit longer for the solution, but I appreciate your ideas.

It turns out I have two goals instead of just one.

1. Increase the clearance between the truck's tailgate and the overhang of the 5th wheel.

2. Lower the front end of the camper when it's attached to the truck to help correct it from riding "front-high".

Help me out, as I try to think through why some of your ideas don't yet click right in my mind, please?

You wrote: "The only way to increase that distance is to increase the hitch height in the bed. Lowering the truck brings the hitch with it and the 5r too, so nothing gained."

My thoughts: The trailer's already riding front-high on its two axles. I don't want to exacerbate that by raising the 5th wheel higher in the truck bed. I want to lower the front of the camper so weight is equally distributed across both trailer axles & all four tires.

Height is already a concern when approaching low bridges, and Forest River has advised me to NOT raise the camper for a couple of reasons:

1. Making the camper ride higher increases it's sideways momentum, making it more tippy when driving around curves. I don't want that.

2. Installing spacers above the axles requires longer mounting U-Bolts. Longer bolts results in greater leverage on them. They must be correspondingly stronger, or the increased leverage may twist and weaken them. (I'd assume a shop that installed longer U-Bolts would know this in advance, and automatically use stronger/thicker U-Bolts, but E-Trailer recommended watching out for this).

You wrote: "Clearances between the truck bedrail and the bottom of the 5th wheel over the bed. The only way to increase that distance is to increase the hitch height in the bed. Lowering the truck brings the hitch with it and the 5r too, so nothing gained. "

After looking it over, it turns out that lowering the truck DOES also lower the hitch, but not quite as you mentioned. The truck's tail gate is offset back towards the camper about four feet; when lowering the truck's height, the camper's overhang doesn't decrease in height proportionate to the amount that the truck's rear axle is lowered. There's a greater space left above the tailgate area as the axle is lowered. Unfortunately, I don't think it would be as much clearance as I'd like.

You wrote: "Identify the make and model of your hitch, and read the manual on how to raise the hitch plate, raising the front of the camper. "

The hitch is a PullRite 4100. The manual does talk about a lift kit that can be installed. But this raises the front end of the trailer even more. That will make the camper ride with even more weight on its rear axle, and even less on its front axle, when it's already riding front-high.

I might consider installing the lift kit AND dropping the truck's rear axle 2". That would keep the trailer as it is, while gaining space over the tail gate. I'll have to do some calculating & measuring to see if it would be enough.

You wrote: "Flipping axles raises the rear of the trailer, not the front." You're correct, but only to a certain extent. It turns out that raising the trailer's height, either with a spacer solution or by flipping the axles, is like raising one end of a 30' board, whose other end rests on a sawhorse. The sawhorse is the king pin, but the area 4' away from the king pin end (where the truck's bed rail is) does see an increase in clearance. Just not as much as one would like, but it does increase the clearance.

Installing a spacer, and flipping the axles, are apparently not jobs compatible with my trailer's torsion axles, due to design. But someone else suggested replacing the axles with a different angle-degree torsion, effectively raising the trailer. This might accomplish the height increase of the trailer, resulting in some amount of space increase over the truck's tailgate. But it brings me back to my original concern about not increasing overall trailer height.

You wrote: "Dealers aren't always your best resource for in use adjustments."

You're correct. It's a sad thing. A "tail light warranty" is what you'd expect when purchasing stolen goods, not a reputable vehicle with a title from a dealer with a permanent location and a reputation to maintain.

I'm not certain what the right solution is, and I've little trust in certain RV Dealers & their shops. Perhaps I'll lower the truck as much as possible (while hating to give up clearance!), and then raise the PullRite hitch. It would be nice to have this all in CAD/CAM so I could predict the results without going through the purchases & work, only to (potentially) have to undo it all.

John, thank you so MUCH for your ideas! They've helped me think more of this through. Please send your analysis of my thoughts. Am I way off base in my thinking or concerns?

Yours,

Rick

P.S.: Smooth roads to you & your family & your rigs!

DuluthCamper · 04-01-2021, 03:13 PM

Thank you, PhillyG, for your ideas!

I've looked hard at my 5th wheels axles. They're torsion style, and I don't see a way of flipping them or relocating the axles below the spring perch. They're quite different from leaf springs.

If there WERE a way to do that, I'd still be hesitant, since I'm already concerned about overall trailer height. Installing the rectangular box spacers you mentioned would also raise the trailer, if there's a way to cut the trailer off its frame at the torsion suspension axles.

But there've been too many low bridges in my travels. I've not hit any, but I'm yet willing to give up a couple of inches of clearance. Maybe eventually . . .

I've a secondary goal in mind, beyond gaining clearance between the truck rails and the underside of the overhang of the camper: leveling the camper front-to-back as it travels. It's already riding high due to the high rear end rake of my 2016 Silverado HD 2500.

I think that lowering the truck, either just the rear end, or overall, will get me some more clearance. At the same time it should help the trailer ride more level, properly distributing the weight on both axles.

Thank you again for your suggestions! If I've shown unclear thinking here, if you disagree with my thoughts, or if you have new advice, please share it with me here! You sound much more experienced than I in this realm.

Yours,

Rick

p.s.: Smooth roads to you & yours & your rig!

Quote:

Originally Posted by phillyg

Yeah, 2.5" is way too little clearance. The recommendation is 5-7". I don't see you can increase it much with smaller wheels/tires that can still carry the required load, leaving spring mods or increasing trailer height. I can't opine about the springs. However, the normal method of "flipping" the axles might do it. Flipping is a misnomer, as it really means relocating the axles below the spring perch rather than above. The best method I've seen is to have thick-walled rectangular box steel, about 6' long, welded to the underside of the frame, and the spring mounts welded to the box steel (make sure alignment is done). Depending on the height, you might not have to flip the axles. I suspect the RV mfgr. advises against it because it raises the center of gravity, but......

DuluthCamper · 04-01-2021, 03:20 PM

Thomas ho---thank you for the idea!

Your suggestion would gain some clearance over the truck rails, but at the expense of raising the front of the trailer even further. It's already riding too high, sadly.

I'll keep looking for a solution, perhaps a combination of steps. I'm looking for a solution that increases clearance while also lowering the front of the trailer--without raising the trailer's height (since I don't want to worry about low bridges any more than I already do.)

Thanks again!

Yours,

Rick

Quote:

Originally Posted by Thomas ho

you could go with a b and w turnover ball with a anderson ranch hitch. snout is adjustable up and down. you can put on the ranch hitch yourself its easy. ball by a ranch supply.

DuluthCamper · 04-01-2021, 03:40 PM

Quote:

Originally Posted by wanderingbob

A lift kit for torsion axles is fairly common , I bought mine for less than $200 from E-Trailer . Fit perfect , took about two hours for the first axle then 30 minutes for the second !

Thank you, WanderingBob.

I considered increasing the trailer height--it would help! Yet Forest River / Rockwood recommends against it. Probably for safety reasons, because it's already riding front-high. E-Trailer also suggested it would be a safety risk, since it increases the tippiness of the camper on turns. They also mentioned they'd be concerned about the longer U-Bolts installed. Longer bolts means the trailer has greater leverage on them, making twisting/straining them a possibility. Longer U-bolts would have to be stronger, maybe thicker, to compensate for the extra leverage the trailer would have on the axles. I really do appreciate your thoughts. If you have other ideas, or specific part numbers, or if my analysis is faulty, please send your clarifications my way!

Thanks again! May your roads be smooth!

Rick

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