Hitch Extension Options on OEM Hitches

HI Folks: I just came across this comment from a person on another truck camper forum and found it interesting and wanted to share it with everyone. cheers christl
"I realize this is a little late but just put a curt industrial hitch #15607 on my dodge that mounts under my oem receiver cost $196 with free shipping. I then went to a welding shop got 5 feet of 2.5x2.5x3/8 tubing 5 feet of 2x2x3/8 tubing, a 2 inch receiver tube, and had a buddy weld it all togethor. I mimicked the superhitch setup by using both oem and curt receiver hitchs and making my own truss extension using thicker steel than superhitch on the truss part. I've got a grand total of $300 dollars into the set up. My truss sticking out of my receiver is 4 feet long, and I have a good piece of mind that my 21 foot sea doo is safe. I just couldn't justify $900 on a hitch setup. Just my 2 cents."

If it is an OEM hitch it should have a label on it stating the class and the capacities .

Christl wrote:
Thanks everyone for your comments as I will again be able to make informed decisions with the information provided. This is especially true for the information provided by mkirsh and kerry4951. If the extension I need is 36 inches from the cross pin in the receiver and as you indicated mkirsh, if the normal hitch shaft (ball to pin) is approx. 9 inches, I will be reducing the design capacity by 36/9=4 times. Therefore if the design tongue load is 500lbs for a Class lll, I must keep my tongue load below 125lbs or switch to a torklift or reese hitch. I am still trying to confirm which class of hitch comes OEM with GMC 3500. Kerry4951 I sure do agree on your comment about the truck advertising pictures. cheers everyone

I just found out that GMC no longer provides a Class for their hitches and that the towing and tongue weight of both are stamped on the hitch they come with. My 2015 GMC 3500 will have a stamped tongue weight of 1500lbs on the OEM hitch. Therefore I should be good for approx. 375lbs of tongue weight using a 36in hitch shaft (cross pin to ball). I believe our 14ft. aluminum duck boat is well under that tongue weight and safely coming with us camping!

Thanks everyone for your comments as I will again be able to make informed decisions with the information provided. This is especially true for the information provided by mkirsh and kerry4951. If the extension I need is 36 inches from the cross pin in the receiver and as you indicated mkirsh, if the normal hitch shaft (ball to pin) is approx. 9 inches, I will be reducing the design capacity by 36/9=4 times. Therefore if the design tongue load is 500lbs for a Class lll, I must keep my tongue load below 125lbs or switch to a torklift or reese hitch. I am still trying to confirm which class of hitch comes OEM with GMC 3500. Kerry4951 I sure do agree on your comment about the truck advertising pictures. cheers everyone

I used the OWM hitch on my 09 Silverado dually for a few years, with a 42" Reese extension. I pull a lighter aluminum trailer with an ATV, probably 2500 lbs,, with electric brakes. The tongue weight is minimal. Then I read a report from a fellow member on this forum who had done the same thing and reported seeing stress cracks on some of his hitch welds. That kinda scared me so I did upgrade to a Reese Titan hitch with the same extension. I continue to use this set up. I do have side support safety chains also.
The thing that always annoyed me are the ads we see with these new fancy HD trucks pulling all this heavy weight. Each truck manufacturer trying to out do the other guy. If thats the case then they should be installing hitches comparable to the Torklift set up, and not these cheap flimsy things that all 3 truck manufacturers are actually putting on.

This is just a guess, but I would expect the "rating" for your hitch with a 36" extension to be about 1/5 of its rating with a standard shank.

Remember torques from high school science class? Force times distance?

Typical standard shanks are around 9" from the cross pin to the center of the ball. You're adding 36" to make a total of 45" from cross pin to the center of the ball.

45/9 = 5

The trailer is 5 times the distance from the receiver. A force of 100lbs at 9" feels like 500lbs to the receiver if it is 45" from the receiver.

THIS IS NOT EXACT. This is just my best guess given my engineering background. The actual de-rating of the receiver might be more, or it might be less. Only the guys who designed it know for sure.

What does the owners manual state for longest recommended extension with factory hitch? 18"?

I switched to a Torklift 20K hitch on my 2015 GMC 3500HD dually, so my truck would fit into my garage, by 1.5" , but I plan on towing a trailer and you can't beat a Super Truss for safe towing. If you have to change hitches go with Torklift.

I would at least want some chains pulling at an angle to help handle the torque magnification of the extension.

I used a Reese 48" extension in my factory '07 Chevy 2.5" receiver to pull my 4,500 pound boat for 2 years. I didn't have any problems with it. I like my current set up better which is a Torklift hitch and extension.