Rob Posted November 8, 2010 Share Posted November 8, 2010 Hey guys, I don't know much about this so I'll ask here:My R612 has a 52" level 5th wheel height with a 39" frame height from the floor. It sits on 11RX24.5 tires. Most of my other truck/tractors are on 10.00RX20, or 11RX22.5 tires. This of course relates to a different 5th wheel height on the other trucks that I've not measured but it seems to be about 48" in height. Does this limit me in any way on my search for a single drop, low profile trailer? I don't want anything running up, or downhill going down the road.Thanks,Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment Share on other sites More sharing options...
RowdyRebel Posted November 8, 2010 Share Posted November 8, 2010 Hey guys, I don't know much about this so I'll ask here:My R612 has a 52" level 5th wheel height with a 39" frame height from the floor. It sits on 11RX24.5 tires. Most of my other truck/tractors are on 10.00RX20, or 11RX22.5 tires. This of course relates to a different 5th wheel height on the other trucks that I've not measured but it seems to be about 48" in height. Does this limit me in any way on my search for a single drop, low profile trailer? I don't want anything running up, or downhill going down the road.Thanks,RobYou can buy 5th wheels that hold the trailer at varying heights above the frame....and that will affect the overall height just as much as anything else between the 5th wheel plate and the ground. Tire size, suspension, frame rail height, etc...for example, an 11R24.5 tire will add an inch over an 11R22.5 tire. Suppose you have a 38K spring ride on one and a 46K spring ride on another truck...the 46K will probably have more leafs or thicker leafs, which makes for a taller spring pack, which may increase the ride height.Keep in mind, you are only talking about a difference of 4".....not likely to have any noticeable affect on a 48' trailer. If my math is correct, a 4" elevation change over 48' is a 0.7% slope...and in all likelihood, it'll be less because the trailer will probably be perfectly level somewhere between the two extremes. If that minor difference is going to bother you.... Quote When approaching a 4-way stop, the vehicle with the biggest tires has the right of way! Link to comment Share on other sites More sharing options...
Rob Posted November 8, 2010 Author Share Posted November 8, 2010 You can buy 5th wheels that hold the trailer at varying heights above the frame....and that will affect the overall height just as much as anything else between the 5th wheel plate and the ground. Tire size, suspension, frame rail height, etc...for example, an 11R24.5 tire will add an inch over an 11R22.5 tire. Suppose you have a 38K spring ride on one and a 46K spring ride on another truck...the 46K will probably have more leafs or thicker leafs, which makes for a taller spring pack, which may increase the ride height.Keep in mind, you are only talking about a difference of 4".....not likely to have any noticeable affect on a 48' trailer. If my math is correct, a 4" elevation change over 48' is a 0.7% slope...and in all likelihood, it'll be less because the trailer will probably be perfectly level somewhere between the two extremes. If that minor difference is going to bother you.... Thanks for the input as I have zero experience in this. I was concerned a lot with swing clearance and don't know if trailers are built to be hauled specifically by a particular setup or are generic in nature. This R612 was purchased and setup new to haul a folding neck lowboy trailer which is all it did. The 5th wheel is mounted to "I" beam that is clamped to the top of the trucks frame rails raising it up. The 5th wheel is also fixed with ramps built up to the back of the platter. I'm assuming that it's commonplace to need to crank landing gear either up or down to pull a trailer with varying pulling units, (tractors). Don't mean to sound naive but I've always repaired these things, never actually worked them.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment Share on other sites More sharing options...
Gambi80 Posted November 8, 2010 Share Posted November 8, 2010 If you get an air ride trailer you can fart with the ride height to level it out. Otherwise I think there's a zillion different 5th wheel combinations out there as far as height goes. Quote Ever wonder how a blind person knows when to stop wiping? Link to comment Share on other sites More sharing options...
David Posted November 8, 2010 Share Posted November 8, 2010 The 52" is not a problem until you hook to a 13'-6" trailer that's made to ride on a 48" fifth wheel. Then you will learn to notice those yellow signs that give you the clearance under bridges. Quote Link to comment Share on other sites More sharing options...
Rob Posted November 8, 2010 Author Share Posted November 8, 2010 If you get an air ride trailer you can fart with the ride height to level it out. Otherwise I think there's a zillion different 5th wheel combinations out there as far as height goes.I'm looking at an older 45' single drop on spring that is in nice shape but needs a floor. The guy went to low profile tires due to height differences and lack of clearance on his rear fenders with a newer tractor that is on low profile rubber. I'm wondering if I could pull it home without problems.The trailer is in Carbondale so not far. The guy is wanting to do some horsetrading for the trailer.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment Share on other sites More sharing options...
RowdyRebel Posted November 8, 2010 Share Posted November 8, 2010 Thanks for the input as I have zero experience in this. I was concerned a lot with swing clearance and don't know if trailers are built to be hauled specifically by a particular setup or are generic in nature. This R612 was purchased and setup new to haul a folding neck lowboy trailer which is all it did. The 5th wheel is mounted to "I" beam that is clamped to the top of the trucks frame rails raising it up. The 5th wheel is also fixed with ramps built up to the back of the platter. I'm assuming that it's commonplace to need to crank landing gear either up or down to pull a trailer with varying pulling units, (tractors). Don't mean to sound naive but I've always repaired these things, never actually worked them.RobThe carrier I'm leased to has low-pro 22.5's....my truck rides on tall 24.5's. That means I've got 2" extra ride height just in the tires & rims...and that's not figuring on suspension, frame rail height, or the 5th wheel. When I drop a trailer, they have to crank on 'em to lower it down to their level before they can hook to it. I can USUALLY back under it easy enough when they drop 'em, though...either by dumping my airbags to lower my 5th wheel, or because the 5th wheel will lift the dolly legs up off the ground (as long as the edge of the 5th wheel gets under the front of the trailer).Sounds like the 5th wheel was raised up to allow for clearance when the tongue is extended...otherwise, you'd risk getting hung up at every corner with a hump in the road. Quote When approaching a 4-way stop, the vehicle with the biggest tires has the right of way! Link to comment Share on other sites More sharing options...
Rob Posted November 8, 2010 Author Share Posted November 8, 2010 The 52" is not a problem until you hook to a 13'-6" trailer that's made to ride on a 48" fifth wheel. Then you will learn to notice those yellow signs that give you the clearance under bridges.Hi David, this is a valid concern as I've purchased a 13"6" furniture van on air with 17.5" tires in Grand Rapids, MI. I don't know if it is set up for the taller, or shorter 5th wheel height. I only have this one truck that is any kind of shape to go to work so this is a concern as I really need to get some things wrapped up before the snow flys. A furniture van is of really no use to me other than storage but the suspension under it is what I'm after to build a trailer fitting my needs.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment Share on other sites More sharing options...
RowdyRebel Posted November 8, 2010 Share Posted November 8, 2010 Hi David, this is a valid concern as I've purchased a 13"6" furniture van on air with 17.5" tires in Grand Rapids, MI. I don't know if it is set up for the taller, or shorter 5th wheel height. I only have this one truck that is any kind of shape to go to work so this is a concern as I really need to get some things wrapped up before the snow flys. A furniture van is of really no use to me other than storage but the suspension under it is what I'm after to build a trailer fitting my needs.RobTake a tape measure with you. Once you are hooked up, measure the height from the top of the trailer to the ground. If it is more than 13'6", you'll have to dodge the scales....easy enough to do if you don't mind running a few extra miles. The extra miles will be cheaper than the fine...just make sure you watch the signs for low bridges. BTW, when ya coming to C'dale? I'm only 30-40 miles South of there...depending on whereabouts in town you'll be going. Quote When approaching a 4-way stop, the vehicle with the biggest tires has the right of way! Link to comment Share on other sites More sharing options...
Lmackattack Posted November 9, 2010 Share Posted November 9, 2010 sounds like you have what is known as a Hi mount 5th wheel. common on tractors that haul Dump trailers in the off road or pull tanker trailers. It gives more space between the frame and trailer bottom and reduces the risk of interfearance. Does it have holes welded to the wheel and mounting plate so that a Bar can be installed and hold the 5th wheel level? if so it was set up for a frameless or 1/4 frame end dump. Quote Link to comment Share on other sites More sharing options...
cgallamore Posted November 9, 2010 Share Posted November 9, 2010 Hey guys, I don't know much about this so I'll ask here:My R612 has a 52" level 5th wheel height with a 39" frame height from the floor. It sits on 11RX24.5 tires. Most of my other truck/tractors are on 10.00RX20, or 11RX22.5 tires. This of course relates to a different 5th wheel height on the other trucks that I've not measured but it seems to be about 48" in height. Does this limit me in any way on my search for a single drop, low profile trailer? I don't want anything running up, or downhill going down the road.Thanks,Robi have the high profile fithwheel on my truck and have had no issues with it......it keeps the trailer off my fenders.... Quote http://www.bigmacktrucks.com/uploads/1272400769/gallery_4852_794_314995.jpg Link to comment Share on other sites More sharing options...
Rob Posted November 9, 2010 Author Share Posted November 9, 2010 sounds like you have what is known as a Hi mount 5th wheel. common on tractors that haul Dump trailers in the off road or pull tanker trailers. It gives more space between the frame and trailer bottom and reduces the risk of interfearance. Does it have holes welded to the wheel and mounting plate so that a Bar can be installed and hold the 5th wheel level? if so it was set up for a frameless or 1/4 frame end dump.There is nothing to hold the 5th wheel stationary in any level or plane. It is also not a sliding setup. The truck was put together new to haul a folding neck trailer and I'm told it was dedicated to this job only.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment Share on other sites More sharing options...
Rob Posted November 9, 2010 Author Share Posted November 9, 2010 i have the high profile fithwheel on my truck and have had no issues with it......it keeps the trailer off my fenders....The 5th wheel sets 4-6 inches higher than the rear fenders on this truck. Assuming king pins are never recessed into the neck of a trailer, I should be alright as far as clearance.Thanks,Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment Share on other sites More sharing options...
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