DIY: Low $ Trailer Hitch Receiver
 

Before anyone flames this thread about installing a trailer hitch on a 370Z, I have a question. How do you get your race tires and wheels to the track?

I would appreciate it if we could keep this thread to improving my design or tips on cutting the bumper bar.

I spent about two weeks studying hitches on the internet trying to find one that would fit on our car. The requirements I had were that the hitch would exit out the fog light opening and that there would be no modification of the bumper cover.

I thought I had finally found one that would fit with little modification. I ordered the Curt #19101 Bumper Hitch which cost $56.00 with shipping. As you may see, it is designed to bolt on to a 2 inch by 4 inch RV bumper. My initial measurement of our 370Z bumper was that it was also two inches thick. Therefore, I thought I had hit the jackpot. All I would need to do is slide the hitch on the bumper and drill two holes to mount it.

http://www.the370z.com/members/resip...-hitch-box.jpg

http://www.the370z.com/members/resip...mper-hitch.jpg

The reality was different. It turns out our bumper bar is more like 2 ¼ inches thick. The hitch would not fit. Undaunted, I was determined to make this work.

Taking a closer look at the bumper I discovered that it is essentially a square aluminum tube thicker in diameter on the front and rear surface and substantially thinner on the top, bottom, and the middle stabilizer. In fact, the front surface of the bumper is about ¼ inch thick. Therefore, if you cut out the 10 inches of the front surface of the bumper it will fit.


Now you are going to have to get a rough idea how far up on the bumper the hitch will need to be mounted to exit the fog light hole. You’re just going to have to use your best guess on this one. You can always cut away more material later. To determine the center of you bumper use the three ridges on the fire wall. The middle ridge is the center.

That is when I put a cutting wheel on my drill and did a little experiment on the bumper. It was going to be time consuming, but I could cut the face of the bumper bar. Then I drew an outline of the hitch on the bumper and started cutting.

http://www.the370z.com/members/resip...bumper-cut.jpg

IMPORTANT: If you are going to do this mod, I suggest that you first determine what and how you are going to use to cut the bumper. I can tell you that even a dremel tool can work but that will take a lot longer. I went through 12 drill mounted metal cutting wheels and 12 dremel cutting wheels. I also ruined my Dremel tool and damaged my electric drill tool in the process. Just take your time and let the cutting wheel do the work.

As you can see, my measurements were really crappy. I suggest that you do a better job than I did. You will need to make five separate cuts because there is a support in the middle of the bumper. First cut the two vertical lines. Then cut the top line horizontal line.

http://www.the370z.com/members/resip...h-half-cut.jpg

Now you are going to have to cut the middle line just above the bracing. When that is complete, you will then have to take a Dremel tool and cut the middle support just behind front side.

http://www.the370z.com/members/resip...bumper-cut.jpg

Once you have finished cutting the bumper take the hitch and make sure it slides up easily on the bumper. You will probably need to do some additional cutting and grinding to facilitate this.

******Now here is the most important step. You will need to determine where the hitch will be mounted to squarely exit the fog light hole. This means supporting the hitch with something like a jack stand on the bumper bar and using wooden shims on the side of the hitch to hold it still. Then take the bumper cover and slip it over the hitch tube and snap it onto the car. Make sure everything is centered and in place. This step is difficult but important. You are probably going to bump the hitch with the bumper cover and knock off your measurements multiple times.

http://www.the370z.com/members/resip...ch-measure.jpg

When you have everything lined up drill the holes in the back of the bumper bar. As you feed in the large included bolts you should insert metal spacers to close the gap inside the hitch. I used an old socket and a crush washer which fit perfectly. Make sure you use plenty of LocTite on the end of the bolts.

http://www.the370z.com/members/resip...tch-spacer.jpg

When you tighten the bolts the hitch will compress slightly on the lower and middle bumper supports creating a surprisingly sturdy connection. I found this out when my 300 pound neighbor came over to admire my work. To my horror, he placed his foot on the end of my receiver tube and gave it a good push. The rear of my car dipped as the suspension compressed. He just looked at me and said “that looks good”.

http://www.the370z.com/members/resip...-installed.jpg

No modification to the Styrofoam bumper is needed. It will just pop right back into place.

http://www.the370z.com/members/resip...hitch-foam.jpg


Now reinstall the bumper cover and admire your work.


http://www.the370z.com/members/resip...76-t-hitch.jpg

I was a little concerned whether I was going to be able to insert the locking pin. However, the area around the fog light hole is very flexible making installation of the pin easy.

http://www.the370z.com/members/resip...-hitch-pin.jpg

And for the coup de grace! Ok. You can flame me on this…

http://www.the370z.com/members/resip...1100-skull.jpg

Nicely done, its a 2 inch setup too. I do recommend reinforcing your bumper boltss as they are weak from the factory. Yours also sit farther away from the body than mine, makes it much easier to reverse

Do you mean replacing the bolts with higher grade ones?

Yes, plus you should extend the bolts through the outer parts of the bumper, not just insidr

I'm not sure I'd be comfortable towing with a hitch attached to aluminum... or did I miss something?

I designed and built one for my S2000 that consisted of three parts that stay on the car and a removable hitch. Basically two plates sandwiched between the car and bumper beam and one attachment point utilizing the diff mounts; the hitch receiver itself attached to these with pins - for quick removal. I was planning to do the same for the Z. I can post some pics of the S one I made if anyone's looking for alternate ideas.

From the few seconds I've spent under the new car (Z), a center attachment seems rather impossible... But are you actually bolting to the car itself (through the bumper beam), or just to the aluminum bumper beam?

Can you clarify?

Which part?

S2000 hitch pics: Trailer Hitch Pics

That's a pretty sweet hitch mount for your S2000.

I would not suggest towing anything very heavy with my setup. Just a small trailer holding three wheels and tires at 45 lbs each (the fourth wheel fits in the spare tire compartment).

I'll be attempting the same type of design on the Z, but I'm not sure that 3 points of attachment will be feasible...

Bump for bad taste...

I always wanted to do something like this.. only If I had something cool to pull around, like a seadoo or bikes.

Sweet ! Any pics of the trailer you use attached to the setup ?

I ordered a small 40 inch by 48 inch trailer from Northern Tools. UPS tracking says it will be delivered tomorrow.

you may also be able to use a hitch for a jeep tj, very simalar disign, but it may be 2 1/4" for the frame on the jeep, which means no cutting on the car...

I would use a design based on this one:

Who makes this trailer hitch : 350z / 370z Discussion

I'd change it up slightly to compensate for the fog light assembly which interrupts what would be a smooth surface on the inside face of the bumper. I'd have a custom cut plate of steel that runs the along the inside face of the bumper with a cutaway for the fog light assembly. You could then use two of the down tubes whereas they only used one on the above link. If you wanted to go further, a forward running tube mounted just behind the diff would add more strength.

The best thing about this design is that you could take it off when not in use. That way no one would know you fuked a fat chick had a hitch on a sports car.