goose neck trailer hookup.

[dave thomas]

Just purchased a M923a1, tractor, Would liken to remove the 5 th wheel plate and add goose neck ball, Would like to pull a 30 foot dual tandium trailer, Any suggestions on the electric brakes for the trailer they are 12 vdc, lights should be easy to change to 24 vdc. New to steel soldiers, any help would be great.

Thanks, Dave

 

[73m819]

I have seen a adaptor fifth wheel plate used, one side had a fifth wheel king pin, the other side had goose neck ball. this was used so the tractor owner could pull a end dump for the job and live in the RV trailer, then when moving to the next job, they pull the end dump to the new job then go back and get the RV useing the adaptor plate.

 

[rosco]

The tractor is a little "overkill" for your gooseneck. You won't know if its back there - by the same notion, you won't know if its not back there either. To respond to the subject though, just make a ball hitch in back of the real fifth wheel, and add special place to hook in the lights, but not disturb the existing applications, useing the rear cross member. Its not likely that you will have a weight issue

 

[USMC4302]

On my non-MV road tractor ('72 GMC 9500), I have a gooseneck ball mounted on a reinforced cross plate just aft of the 5th wheel. I retain my regular 5th wheel and I have the ability to pull gooseneck trailers, too. Even though the G/N ball is behind the axle, so far it hasn't been an issue. I have a 40-foot flat trailer I've pulled in excess of 30,000 lbs and the truck hasn't noticed. I doubt the 923 would, either. Don't give up the 5th wheel!

 

[quickfarms]

I have seen two types if fifth wheel rv trailer hitches. The one you are referring to that uses a ball and the other one uses a small fifth wheel.

 

[wreckerman893]

When I had my M915 I bought this to pull our 28 foot gooseneck. Never used it since I sold the truck.

 

[SLOrazorsedge]

Your probably going to want a 24v to 12v converter. They're not cheap, run in the $250+ arena. I think Erik's military surplus has them online

 

[ichudov]

On my non-MV road tractor ('72 GMC 9500), I have a gooseneck ball mounted on a reinforced cross plate just aft of the 5th wheel. I retain my regular 5th wheel and I have the ability to pull gooseneck trailers, too. Even though the G/N ball is behind the axle, so far it hasn't been an issue. I have a 40-foot flat trailer I've pulled in excess of 30,000 lbs and the truck hasn't noticed. I doubt the 923 would, either. Don't give up the 5th wheel!

This is the best idea so far. My opinion.

 

[Trailboss]

This is the best idea so far. My opinion.

You just might have to be careful when hitching to a semi trailer so the trailer kingpin doesn't hit the gooseneck ball. I'm not sure of the clearance if the semi-trailer is riding the ramps when you hitch. If you have the trailer raised high enough to clear the ramps, you're probably safe. I may be talking out of my hat, and it may not be a problem, but I don't have a gooseneck ball to put the tape measure to.

 

[ichudov]

You just might have to be careful when hitching to a semi trailer so the trailer kingpin doesn't hit the gooseneck ball. I'm not sure of the clearance if the semi-trailer is riding the ramps when you hitch. If you have the trailer raised high enough to clear the ramps, you're probably safe. I may be talking out of my hat, and it may not be a problem, but I don't have a gooseneck ball to put the tape measure to.

You are actually talking out of your hat

The fifth wheel on M931 is 12 inches above the frame. (which I think is crazy).

i

 

[USMC4302]

Well for what it's worth, here's a picture of my civvie set up. Could you do something similar on the 931?

 

[tobyS]

Wreckerman, I can see the advantage of having that trailer adapter but note that the tractor hitch has no ability to swivel side to side. That would make the trailer have extreme force twisting, probably bending the frame. It could be made work well with a lengthwise swivel fabricated in however.

USMC, that would make a nice setup but require cross member frame removal and modification. May well be worth it but I would want to retain the pintle. I wonder about making a 923 cargo shorter and have a center pull. Is that a 2 5/16" ball?

 

[quickfarms]

Well for what it's worth, here's a picture of my civvie set up. Could you do something similar on the 931?
View attachment 459029

I like your mud flaps

If I remember correctly they also make a retractable mount.

 

[wreckerman893]

Well for what it's worth, here's a picture of my civvie set up. Could you do something similar on the 931?

You can but it puts the weight behind the wheels instead of on top of them where you get the most traction. In my opinion it would cause the front end to raise up more than if you had the weight on the 5th wheel itself. Just my opinion for what it's worth.

Wreckerman, I can see the advantage of having that trailer adapter but note that the tractor hitch has no ability to swivel side to side. That would make the trailer have extreme force twisting, probably bending the frame. It could be made work well with a lengthwise swivel fabricated in however.

He said he has an M932 tractor. It has a 5th wheel that allows it to move on uneven terrain (you have to unbolt and move the locks). If he wants to retain the ablilty to pull semi-trailers he can get the adaptor I posted and use his gooseneck.

 

[tobyS]

So the fifth wheel hitch can rotate not only front to rear, but side to side? I've never seen one. That would make a difference with the adapter you posted, since it is fixed to the frame with no rotation. Are you sure that is the type Dave has?

I too would retain the semi hookup if I had one, but with most trailers they probably (without measuring) would not reach to the center of a tractor fifth wheel and have turning clearance. USMC's setup would not have that issue and unless a really heavy trailer, it wouldn't seen to have much effect on the truck front. Perhaps USMC can tell how it performs, if he has used it with a heavy trailer.

 

[USMC4302]

I've had a 40-foot gooseneck flat trailer on that hitch with approximately 20,000 lbs on it (30 concrete well rings) with no issues (no big hills or heavy traffic) but that was probably too much for several reasons. I wasn't going that far and I don't like putting that much weight on the G/N. I routinely haul a 25' G/N trailer at 14,000 lbs, which is very comfortable and the truck doesn't even feel it back there. More than the 20,000 lbs and I would probably start having issues with the hitch being behind the axle ... but at that point, I would just use the regular 30-ton lowboy on the 5th wheel anyway.

 

[KaiserM109]

On my non-MV road tractor ('72 GMC 9500), I have a gooseneck ball mounted on a reinforced cross plate just aft of the 5th wheel. ... Even though the G/N ball is behind the axle, so far it hasn't been an issue. ...

The reason over-the-road trucks mount their 5th wheel either in front of a single axle or closer to the front axle is because of the way a trailer starts into a turn. If it is mounted behind the center of the power point, as the tractor starts into the turn, the trailer actually starts the other direction. If you get everything just right (actually wrong) a small movement of the truck, such as dodging something in the road, can start an oscillation.

Double and tripple trailers occationally have trouble with the second or third trailer swaying because of this. I think 73m819's idea is the best.

 

[Ddmk18]

This adapter With the xm381's adapter he offers many different variations mine works great

 

[tobyS]

Yea KeiserM109, I know exactly what you describe and would expect more problems with a heavy load, like USMC describes. As he states, he goes to a bigger trailer on the fifth wheel when the load gets larger and heavier. That ball max may be 20k or so to do it safely.

I like 73m819's idea too, but one would have to measure to see if the trailer clears. A neck extension may be necessary, which one may want to avoid.

My nephew rented a U-haul truck and car trailer to move to Idaho from Indiana, trailer(ing) his car. I helped him with the drive out. The distance from the back axle to the hitch was huge and the trailer distance from it's hitch to the axle was small. I can't imagine a worse setup. Unfortunately he did not understand the consequences of that oscillation that you describe. I do. On about the third time of being woken to major oscillation, I decided he could not drive the rig safely and took the wheel from then on. We made it without a wreck but it was pure luck that the oscillation did not rapidly degrade into out-of-control with him driving @70+.

 

[m16ty]

While you can overload things by having the hitch behind the axle, you'll never notice it with a gooseneck mounted even on the very back behind a 5-ton. It would really be no different than pulling a pintle hitch trailer of the same size (they are mounted as far back as you can get.