Hitch custom fabrication

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(Created page with 'Lots of rod builders are building vehicles that could make annual trips to far away places, but may not carry enough stuff. Or you may want to build and take a teardrop trailer f…')
 
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Lots of rod builders are building vehicles that could make annual trips to far away places, but may not carry enough stuff. Or you may want to build and take a teardrop trailer for a little mild camping. Whatever. You can order a new hitch for any pickup built in the last 20 years, but not much else. And when you find something close, it's nearly guaranteed to be a weak class 1, or maybe a class 2. By comparison, most pickups start at class 3, and any full-size can have a class 5.
 
Lots of rod builders are building vehicles that could make annual trips to far away places, but may not carry enough stuff. Or you may want to build and take a teardrop trailer for a little mild camping. Whatever. You can order a new hitch for any pickup built in the last 20 years, but not much else. And when you find something close, it's nearly guaranteed to be a weak class 1, or maybe a class 2. By comparison, most pickups start at class 3, and any full-size can have a class 5.
I have an '84 Trans Am, a '79 Chevy C-20, and an '06 GMC Sierra. I had no trouble finding a new Curt class 5 for my '06, at $168 delivered. Great. What about my '79? Since that chassis continued through 1990, I found a Reese for $270, delivered. Ouch. And my car? I found a new Curt, but only rated to half as much as my car is rated to tow.  
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I added all 3 costs, then decided I could buy a welder and the steel for much less. Pics next month.
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For example; I have an '84 Trans Am, a '79 Chevy C-20, and an '06 GMC Sierra. I had no trouble finding a new Curt class 5 for my '06, at $168 delivered. Great. What about my '79? Since that chassis continued through 1990, I found a Reese for $270, delivered. Ouch. And my car? I found a new Curt, but only rated to half as much as my car is rated to tow.  
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I added all 3 costs, then decided I could buy a welder and the steel for much less.  
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Read everything I've typed before starting.  
 
Read everything I've typed before starting.  
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First was a bit of cardboard, a sharpie, and some scissors. Use this to make templates. To do this, you need to know that you'll be using square steel tubing, which is commonly sized by the outside measurements. And the minimum measurement you'll be using is 2.5" My pickups are using 3" for the cross-tube. Your side-plates will be 1/4"-thick. Don't forget plenty of gussets. Also, you need at least 3/8" clearance everywhere, as the heat of welding will distort the cross-tube, by a full 1/4" in the case of my '06.
 
First was a bit of cardboard, a sharpie, and some scissors. Use this to make templates. To do this, you need to know that you'll be using square steel tubing, which is commonly sized by the outside measurements. And the minimum measurement you'll be using is 2.5" My pickups are using 3" for the cross-tube. Your side-plates will be 1/4"-thick. Don't forget plenty of gussets. Also, you need at least 3/8" clearance everywhere, as the heat of welding will distort the cross-tube, by a full 1/4" in the case of my '06.
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Once the templates are done, get some tape, and try to make it something that can be test-bolted to the vehicle. Good clearance everywhere? Adequate attachment to never rip loose, or distort the chassis? Good, move on to building a wooden mockup. Now you need a drill and a jigsaw, and if you get a really good one, you can also use it to cut most of the steel later on. I did.  
 
Once the templates are done, get some tape, and try to make it something that can be test-bolted to the vehicle. Good clearance everywhere? Adequate attachment to never rip loose, or distort the chassis? Good, move on to building a wooden mockup. Now you need a drill and a jigsaw, and if you get a really good one, you can also use it to cut most of the steel later on. I did.  
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The wooden mockup is easier, quicker and cheaper to revise if necessary, and it is easier to test-fit, plus it's disposable. Save your templates.  
 
The wooden mockup is easier, quicker and cheaper to revise if necessary, and it is easier to test-fit, plus it's disposable. Save your templates.  
 
Once the wooden mockup is built, bolt it to the chassis exactly as if it were steel. Then go for a test drive. If you manage to rip it loose, then you need to revise the design, or stay off the Rubicon trail, if that's where you freed it :)
 
Once the wooden mockup is built, bolt it to the chassis exactly as if it were steel. Then go for a test drive. If you manage to rip it loose, then you need to revise the design, or stay off the Rubicon trail, if that's where you freed it :)
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If you're bolting to an actual frame, such as my pickups, then use at least 3 bolts per side, 1/2" grade 8. If not, then plan on welding in large steel plates, probably 1/8"-thick, to spread the load out. Plan on more plates inside, and plenty of through-bolts to sandwich as much of the chassis as possible. This is how racing roll-cages are secured to cars without frames (like my Trans Am) Typically those sandwich plates are like 6" x 6", so plan accordingly.  
 
If you're bolting to an actual frame, such as my pickups, then use at least 3 bolts per side, 1/2" grade 8. If not, then plan on welding in large steel plates, probably 1/8"-thick, to spread the load out. Plan on more plates inside, and plenty of through-bolts to sandwich as much of the chassis as possible. This is how racing roll-cages are secured to cars without frames (like my Trans Am) Typically those sandwich plates are like 6" x 6", so plan accordingly.  
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If you have a length issue, note that adding length is best done in the side-plates, not the tail tube. Tail tubes come 12", so that's 9.5" past the cross-tube. If you must add length to the tail tube, then plan on up-sizing every tube by 1/2", and using a reducer inside the tail end.  
 
If you have a length issue, note that adding length is best done in the side-plates, not the tail tube. Tail tubes come 12", so that's 9.5" past the cross-tube. If you must add length to the tail tube, then plan on up-sizing every tube by 1/2", and using a reducer inside the tail end.  
With the wooden mockup finalized, you can dis-assemble it and take the parts to buy the steel equivalents. They'll cut the cross-tube to your desired length, at a good low cost, since your jigsaw won't do that.  
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With the wooden mockup finalized, you can dis-assemble it and take the parts to buy the steel equivalents. They'll cut the cross-tube to your desired length, at a good low cost, since your jigsaw won't do that.
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Once the steel is cut and the side-plates are bolted in, time for some spot-welding. Then it can be removed for the bulk of the welding.  
 
Once the steel is cut and the side-plates are bolted in, time for some spot-welding. Then it can be removed for the bulk of the welding.  
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Don't paint it yet, just clean up all the welds. Re-attach it to the vehicle, with the final bolts, but grade 5 nuts. Now go find a trailer 50% heavier than you expect to ever tow, and have it brought to a deserted country road at a very non-busy daylight hour. Hopefully a rough road. If your hitch is going to pop a weld or otherwise fail, you want it to happen here and now. And you want the guy in the pickup close by. So, drive rough, with your window down and your radio off. If you hear any metallic noises, stop and cautiously investigate.  
 
Don't paint it yet, just clean up all the welds. Re-attach it to the vehicle, with the final bolts, but grade 5 nuts. Now go find a trailer 50% heavier than you expect to ever tow, and have it brought to a deserted country road at a very non-busy daylight hour. Hopefully a rough road. If your hitch is going to pop a weld or otherwise fail, you want it to happen here and now. And you want the guy in the pickup close by. So, drive rough, with your window down and your radio off. If you hear any metallic noises, stop and cautiously investigate.  
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Once you're satisfied with your deliberate abuse, put the trailer back on the pickup, and go remove your hitch for inspection, then repair and more testing, or painting and final installation.  
 
Once you're satisfied with your deliberate abuse, put the trailer back on the pickup, and go remove your hitch for inspection, then repair and more testing, or painting and final installation.  
In my case, I started with my '06 because I could order the CURT if my idea was flawed. But I typed here exactly what I did, and I feel very comfortable with this.  
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I accept no liability for other ideas, other designs, other people's welding, steel or bolts from any source but mine, and / or any vehicles other than mine. Use only as directed, your mileage may vary, limit one per customer, may cause drowsiness, and any / every other disclaimer you've ever heard or read.
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In my case, I started with my '06 because I could order the Curt if my idea was flawed. But I have built custom hitches before, all successful. So I typed here exactly what I did this time, and I feel very comfortable with this.  
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[[Category:Undeveloped General hotrodding articles]]
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[[Category:Undeveloped articles]]

Latest revision as of 02:48, 2 December 2012

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