trailer saver air 5th wheel install

[hot rod]

OK, so I'm finally getting my Topkick 6500 ready to tow. Bought a trailer saver air ride 5th wheel hitch for it, as the truck is leaf sprung and rides like a brick and I figure the cost of the hitch will be worth it in the long run vs. wear and tear on the trailer.

So I'm ready to jump in and fab up a mount for it as soon as it gets here next week. By my quick measurements it is going to have to sit down between the frame rails by several inches, as opposed to on top of the rails as I have seen on similar trucks, due to the low trailer I have. It is a 2000 trailer, which I picked up for a bargain price in like new shape, but which means it was built basically the last year before all the duallys started getting a taller stance when Chevy changed in 2001 and Dodge changed in 2002 etc., and now they build the overhang area a little higher to accommodate taller trucks. So short story long, I need to mount my hitch a little lower.

Has anyone seen one mounted that way? Or even better, have pictures? I know I can fab it up, just hoping for a few other good ideas before I start welding stuff together, I know y'all will toss me a few ideas I did not think of. The mounts I have seen, and all the trailer saver instructions show, is basically a big flat 5/8" thick steel plate that gets attached to the top of the frame rails, and drilled to bolt down the hitch. I need to be lower, so I'm thinking of something with side plates that bolt inside the C of the framerails, drilled and bolted through the rails, then a couple of crossmembers maybe out of heavy 2x4 channel welded across the gap, and the steel plate on top of the channels. Sort of like the framework you see for an underbed gooseneck hitch for a pickup, but much heavier.

Thoughts?

[blizzardND]

you could just put lift blocks on the trailer axles...
-blizz

[hot rod]

Blizz-

I've actually considered that, but for a different reason. The trailer has triple 6000# 6 lug axles and 15" tires that are just barely adequate for the load I carry (just under 18000# on the axles, and 4000# on the pin), and I have looked into replacing them with 7000# 8 lug axles and 16" tires with a heavier rating. That would require some sort of spacers between the axles and trailer frame to create some clearance for the taller tires vs. the wheelwells in the trailer. I talked to a guy here in Ohio that was in the business of converting 5th wheels campers up to 8000# axles and 17.5" tires, and they space the axles down for those taller tires. I was a little suspicious of spacers in that crucial area, but apparently they do it on heavier trailers than mine. Any thoughts on material for that?

I actually had not thought about the axle project for a while now, that was sort of a separate issue from the "toter" project, but that just might be the ticket to kill 2 birds with one stone. Even if I did it on a budget and spaced down my existing axles by 1", and gained an inch of ground clearance from the taller 16" tires, that would help my pin height by 2" and should be just what I need to mount the hitch to the top of the frame rails on the Topkick.

Any idea what the "correct" height off the ground is for a rv fifth wheel hitch? There has to be some sort of optimum range to be able to hook up the average camper and roll. I've asked a couple of local RV dealers that install hitches that question, and they look at me like I'm stupid and say "we just adjust the hitch on the trailer to fit the truck". Well there has to be some sort of ideal spec there, fifth wheel hitches only have a limited amount of adjustment on the trailer side. And I'd like to be able to pull an average fifth wheel camper with this if I want to (preferably without having to unbolt and move the entire pinbox), so I don't want to set it up where I can only pull my trailer, and the height is off for anything else.

[hot rod]

Got the Trailer Saver hitch delivered yesterday. Very heavy duty top quality hitch. Makes my 22K Reese fifth wheel look absolutely flimsy.

These things are $3000 new, got this one on ebay for $1500. Looks like new, just missing a few airline fittings and such, no big deal. Nothing beats half price!

Now I just need to find a fab shop to cut me the steel plate, fire up the welder....

[Bob86ZZ4]

Have you looked around on the escapees hdt forums? HDT - Escapees Discussion Forum
I bet you could find the hitch height most common there. There's also the heavy haulers resource guide here: The Heavy Haulers Resource Guide & HDT Rally Site - Escapees Discussion Forum

I've gone to two hdt rallys in Hutchinson, Kansas. Spending a couple weeks visiting with lots of experts in heavy 5th wheel trailers. My take on it is the axles/brakes/tires on these things are the most underbuilt and prone to problems areas. Knowing what little I do about a heavy 5th wheel trailer if I was to haul one I'd upgrade the axles/brakes/tires to the heaviest heaviest heaviest duty ones I could possibly get under there. No matter what amount of fab work is needed. I'd get some of those auxiliary axles from a dump truck with 17.5" tires, air ride, etc.... As far as I know nobody has put those under a 5th wheel trailer yet. But, there's got to be a way to do it. Those axles aren't that expensive and they've got good air brakes. And, if you did it right using the large air bags those things have you could lift two of them for manuevering into parking spots. That would be cool. At a minimum how about doing to measuring and figuring on what a finished height for something like that would be and mount your t/s hitch according to what that might be? Then a bit down the road you can upgrade those axles/brakes/tires and it'll be just right.

BlizzND, you could figure out how to add those axles couldn't you? The guy from Doonan Trucks was at the 2010 rally saying he thought it could be done. Somebody's got to be the first in anything.

[Bob86ZZ4]

Going from a 15" to a 16" is only going to give you 1/2" more height, isn't it? All other things being equal.

[Bob86ZZ4]

I just did a search for tag axles on truckpartsinventory.com and found quite a few: Truck Equipment/Accessories | Tag Axles - Truck Parts Inventory - Heavy duty truck parts results

Looks like these axles are up in the 10-20k lbs range. So, you'd only need two of them. One of them I saw said 34" chassis width. I'd guess that would be pretty standard. How does that compare with your 5th frame?

[volvoman]

if you put fifth wheel below frame rails will trailer hitch clear rear cross member on truck? i think standard semi truck 5th wheel is 48" from ground to top of plate when its flat. from what i know about goose neck trailers is they adjust trailer hitch so bottom of trailer is as straight as possible. if you adjust trailer up or down would it change weight on hitch? any solid block of steel would work for spring spacers. just need longer u bolts. several semi trailers have blocks you can buy.

[hot rod]

Bob- Thanks for the links to the escapees forum, I've not browsed over there for a while, I'll do some digging.

My current 15" tire size is a 225/75/15, the bigger of the 2 "standard" 15" trailer position tires, and is 28.3" tall. The Goodyear marathon trailer tire in 16" is a 235/80/16 which is 30.7" for a 7/10" change in ride height/wheelwell clearance. But I am leaning towards the Goodyear G614 235/85/16, which is a heavier tire and is 31.7" tall for a 1.2" difference in ride height/wheelwell clearance. I don't have that kind of room in the wheelwells so the axles would need to be spaced as well.

My trailer is a 40' pace race trailer with living quarters, triaxle, not an RV type fifth wheel. It was a gooseneck, and I have the fifth wheel adapter on the trailer. Not really any room for any other type of axle with the way it is built except for a heavier version of the Dexter trailer axles that it uses. Definitely can't go to a tandem without rebuilding the entire trailer, it would be easier to start over.

Volvoman- I should not have any problem with the pin clearing the crossmembers backing in. The hitch is 10" from the base to the top of the plate, and I only need to drop it a few inches between the rails, the fifth wheel itself would still be well over the frame rails. My adapter on the trailer is already adjusted up as far as it will go to get the trailer level. It seems this setup drops a little farther than on a trailer with an actual fifth wheel pin box.


The thing is I want to set the truck up to be as "standard" as possible in regards to hitch height, but still be able to tow my current trailer. I know my current trailer is an unusual setup, and don't want to match the truck to that and find I need to redo the truck if I get a different trailer, or need to hook to somebody else' trailer. The Trailer Saver has an inexpensive gooseneck adapter I'm going to buy so I can go either way if needed. It seems like most guys with similar trailers use a gooseneck. I like the fifth wheel for ease of hookup. I'm too old to crank the landing gear a hundred times to clear the ball, then let it down to level the trailer, then crank back up to hook the truck. The fifth wheel is way easier, and worth my trouble to set it up the way I want.

I figure it's easier to do my thinking on the forum, rather than with the welder. Easier to change the plan halfway through. Thank for all the ideas, keep them coming.

[Bob86ZZ4]

Not tandem/dual wheels. I'm talking about those single tire add-on axles that you see on larger dump trucks. They have a big air bag that runs them up and down as needed for extra weight carrying on the dump truck. I think those look like they'd be the cat's meow on a heavy race trailer like yours. BlizzND, this is right up your alley. What do you think?

[hot rod]

Finally getting the tools dirty on this project.

I found toterman's thread on the escapees forum where he installed his trailersaver hitch, and it was close enough to my situation to steal his ideas (thanks!) and mount 2 4" angles to the framerails to support a steel plate about halfway up the frame rails. I needed the mounting plate to be 4" below the top of the framerails for the heights to work out with my trailer. I had a local fab shop cut a 46" x 31" x 1/2" steel plate with all the mounting holes already cut in to save a bunch of drilling. Hensley supplied a drawing on their website of the mounting hole locations (14 of them) and the fab shop just programmed the holes and cut them in when they cut the plate to size. Now I just need to drill the 6 5/8" holes in each framerail to bolt the angles to the frame (not looking forward to that!) and then I'll weld the plate to the angles top and bottom.

In the meantime I had the cab painted white to match the trailer. No more Schwan's harvest gold! This rest of this weeks project is to sandblast and paint the propane tanks and frame and get that painted prior to bolting the hitch down.

Good to be doing actual work instead of planning. Hope to be towing the trailer in a couple of weeks, then figure out what to do for a downsized box.

Note: is there an easy way to add pictures?