Custom trailer hitch

[Rutjes]

Hey guys,

My current trailer hitch is kinking the frame on my '98 K1500 so I'm designing one of my own. I'm using my Iveco Daily hitch as a reference. Here's a 3D drawing of the design I have so far:




I plan on removing the stock X shaped crossover and replacing it with a custom made one as seen in the second drawing. The side plates will be laser cut from 10mm thick steel (about 3/8"). I did not draw them in yet, but there will be gussets between the rear crossmember tube and the tube that holds the hitch. The bolts highlighted in green are where the leaf spring hanger is mounted, I'm re-using those holes. I'm thinking of using M14 bolts. The crossmember tubing is 80x40x3mm and the tube that holds the hitch is 60x60x6mm.

Will adding a 10mm plate between the frame rails and the leaf spring hanger cause any problems? I have come across Rust Buster frame repair kits that do the same thing, but they are 4.78mm thick (3/16"). What do you guys think, will it be fine or will it cause binding in the hangers or shackles?

 

[SnowDrift]

Before I would make a suggestion on a project like this, I believe it would be wise to ask what is the cause of the problems you are experiencing? Then we can work from there.

 

[Rutjes]

I will try to explain.

The current one is mounted to be bottom of the frame rails. Where it is mounted to the frame is very short while the whole thing is very tall. Forces from the trailer pushing against it makes the whole thing want to rotate. This is kinking the frame upwards on the front side of where it is mounted to the frame.

My thinking is that by making the mounting to the frame longer and having it sit as high up against the bumper as possible will distribute the forces over the frame rails much better.

And as a plus, it will look good. The current one is an eye sore.

I will take a couple of pictures of the current hitch when I'm at the shop tonight.

The truck is supposed to me my daily driver, but is also my back-up for when one of my Iveco Daily's is out of action. I pull heavy trailers for my work. Also, my girlfriend will be using it for her mobile (candy) store in the near future.

 

[Will L.]

Include pictures of the crossmember you are talking out

 

[MrMarty51]

The 1993 K1500 GMC I once owned, the hitch was mounted under the frame, on the lower portion of the [ channel. That design was tearing out the bolt holes.
I used thick hard warshers on the inside of the lower rail and that stopped the hitch from tearing out the bolt holes.
I think if it were me building this, I would run those mounting pads that bolts to the frame full length instead of having two small pads on each side. If there are no obstructions. Maybe the same on the outside to sandwich the frame.
Maybe get a couple of pics of the current setup as it is mounted to the wehicle.
Nothing better in the world than over kill.

 

[jrsavoie]

The 1993 K1500 GMC I once owned, the hitch was mounted under the frame, on the lower portion of the [ channel. That design was tearing out the bolt holes.
I used thick hard warshers on the inside of the lower rail and that stopped the hitch from tearing out the bolt holes.
I think if it were me building this, I would run those mounting pads that bolts to the frame full length instead of having two small pads on each side. If there are no obstructions. Maybe the same on the outside to sandwich the frame.
Maybe get a couple of pics of the current setup as it is mounted to the wehicle.
Nothing better in the world than over kill.

Whichever one of the hitches I messed with had rectangular plates set im the the frame so the hitch was not hanging on the holes

 

[Rutjes]

I took some pictures of the existing hitch and crossmember. In the first 2 pictures you can see how it is pushing up against the frame.

I think if it were me building this, I would run those mounting pads that bolts to the frame full length instead of having two small pads on each side. If there are no obstructions. Maybe the same on the outside to sandwich the frame.
Nothing better in the world than over kill.

That has been on my mind and with you also mentioning it, I think I will.

Plus, any extra weight back there will be useful, especially when towing. One thing I have noticed about these trucks is that the rear does not stick to the ground very well.

Nothing better in the world than over kill.

I prefer over kill as well.

 

[Will L.]

Ok, what you’re are loosing from the design is the diagonal support.
Add a large X in the middle of your crossmember with same square tubing you are using to build the new crossmember. - guessing you are using 1/4” wall tubing for that? If you don’t want the X, just use some of your flat plate and cap the top of it- that will create the same support. Just stitch weld it on.

Bumping out the leaf spring hangers won’t hurt anything provided you are replacing the leaf pad mounts on the axle to accommodate the wider spread.
Obviously make sure you aren’t running some crazy deep offset rims that pushes the tires to close to the now wider leaf spring position.

 

[dbrannon79]

That hitch on your truck looks awfully short for what it is. I am used to seeing receiver hitches with both front and rear mounting points. if I am looking at the photos correctly your current hitch only has one mount point on the frame giving it a weak spot for tongue weight. do you know what that current hitch is rated for tongue weight?

 

[Rutjes]

That hitch on your truck looks awfully short for what it is. I am used to seeing receiver hitches with both front and rear mounting points. if I am looking at the photos correctly your current hitch only has one mount point on the frame giving it a weak spot for tongue weight. do you know what that current hitch is rated for tongue weight?

It is very short indeed. I have not seen a data plate on there. I think these where made for or by the company that imported these trucks back in the. They are very odd. Same with K30's. I've seen multiple around here with a receiver hitch that looked custom made, but I've seen them on more K30's here in the Netherlands.

Ok, what you’re are loosing from the design is the diagonal support.
Add a large X in the middle of your crossmember with same square tubing you are using to build the new crossmember. - guessing you are using 1/4” wall tubing for that? If you don’t want the X, just use some of your flat plate and cap the top of it- that will create the same support. Just stitch weld it on.

Bumping out the leaf spring hangers won’t hurt anything provided you are replacing the leaf pad mounts on the axle to accommodate the wider spread.
Obviously make sure you aren’t running some crazy deep offset rims that pushes the tires to close to the now wider leaf spring position.

1/4th seems a little thick? I have tubing that is about 1/8" laying around. Wouldn't that be sufficient once it is all welded up like in the drawing? Maybe with some gussets or like you said, a plate to cap it off. Stock crossmembers are thin stamped steel, they don't look much thicker then 1/8".

I have a couple sets of leaf spring perches from RuffStuff laying around for my K30. D60, D70 and 14B FF. Maybe I can use one of those sets, but I'd rather not.

Maybe loosening the u-bolts before mounting will prevent adding tension. If the Rust Buster 3/16" pieces don't require any additional modifications, maybe I will get away with 3/8".

I can have the side plates bent so they can be mounted to the bottom of the frame, like most aftermarket receiver hitches, but to me it seems stronger mounting them to the sides.

 

[Will L.]

Oh yeah- also- HOLY CRUD! How much tongue weight did someone have on it?!?

Actually I get the feeling someone rear-end collision on the hitch.

 

[Rutjes]

Oh yeah- also- HOLY CRUD! How much tongue weight did someone have on it?!?

Actually I get the feeling someone rear-end collision on the hitch.

I couldn't say if it happened before or after I got the truck. Maybe both. I mainly tow drawbar trailers, so I don't usually have a lot of tongue weight on the hitch, but they are heavy and with such short mounting and being tall I can see how the receiver hitch can be pushed into the frame like that.

 

[Rutjes]

Any ideas about the following:

Adding a lift kit has been on my mind for a while. Unfortunately I had to delay this project. Anyway, I was looking at combining the Rough Country 4" lift kit with a shackle flip from Offroad Design. Now with this new hitch, the shackle flip gets a little more complicated... or not... What if I continue the hole pattern from the original hanger downwards and just bolt it on lower then it is stock? Maybe even flip it over to go from a tension to compression shackle like the ORD kit does?

 

[Will L.]

The shackle flip is desired not just for adding height but articulation off road.
Not sure if that is your goal- softer offroad with a little more suspension travel…
Kinda think you are using it the opposite way would be my guess.

If you are going to use it offroad and for towing those trailers, seriously consider adding a heavy duty sway bar that just has quick pins to release it for offroad.
Then do the higher arc leaf springs that are still soft rated, and add air bags for handling the weight as a work truck.
Then for the shocks- something like the Rancho adjustable that have the control on the dash.

 

[Rutjes]

To be honest, the lift will purely be for aesthetic reasons. I know for towing it would be better to keep it as is.

 

[Rutjes]

Last week I spent some time removing the rivets. Drilled the holes to 12mm and put in grade 8.8 M12 bolts. Just a couple of rivets left that hold the stock crossmember in place. I'm getting good at removing them. I spent A LOT more time removing them from my K30.



Today I traced my drawing onto cardboard and cut it out to do a test fit.



It is close, but it did need some adjustments, so here is the new drawing:



The dashed orange line is the old drawing. Don't know when I'll get another chance to test fit. Maybe next week.

The added bolt holes are an idea I'm thinking about. I figure they would allow me to move the shackle hanger down for lifting the truck? Maybe even move it down and flip it to switch from a tension to compression shackle? A lift/flip kit from ORD or similar will no longer be a bolt on modification. Any thoughts on this?