KDS Class III/IV Hitch

I am finalizing the design on a Class IIII/IV wagon hitch. The goal is to have a design that fits 77-96 wagons. Here is a sneak peak at the design, you will see the chain plate, receiver tube are not in the model, but i wanted to get the side plates out to my laser cutter so he can get working on those ASAP.


The hitch uses the ~17mm hole in the underside of the frame rail, as well as the 4 lower bumper shock bolts, similar to how the production hitches were made when they were still available. . The bumper bolts are will be upgraded to 10mm bolts, likely grade 9.8, up from the stock 8mm bolts. Minor drilling will be needed to open the holes up from ~9mm to 10.5, aka roughly 13/32. You will see that i have included access to attach the dual exhaust hanger brackets for the LT1 cars, and the hitch should not interfere with the earlier single exhausts that route closer to the fuel tank.


Hardware includes:
2-internal frame plates to keep the bolts from turning
2- 1/2" Carriage bolts
4- M10 bumper mount bolts
4-M10 flange nuts
4- heavy self tapping screws for the exhaust brackets.

I am targetting a price of $225 + shipping. This will include all mounting hardware required and I intend to ship them uncoated/unpainted, since they get chipped up in shipping anyway. I'd also like to do these in batches, so feedback on a group purchase is welcome.  

Please let me know your thoughts, all feedback is welcome.

I know everyone appreciates your effort as they can't be found anywhere.  I also realize that you are new to the forum.  Hate to be the bearer of bad news, but there is a forum member who makes them, powder coats and ships for @ $150.  Not sure of the exact price, but it is close.  I realize you probably weren't aware of that.

You might want to check out this thread:   https://gmlongroof.4umer.com/t10451-class-3-4-hitch

Tom

I don't think $225 is unreasonable. I think rabalc said he was going to up the price a bit as he spent more time on them than he thought.

One note since I just installed a hitch, if you take off the bumper, you have good access into the frame to hold the back bolts.

autoarcheologist wrote:

I don't think $225 is unreasonable.  I think rabalc said he was going to up the price a bit as he spent more time on them than he thought.

One note since I just installed a hitch, if you take off the bumper, you have good access into the frame to hold the back bolts.

The pricing is prelimimary. I priced them in the ballpark of the still-available sedan hitches. And you likely realize that very  low volume production of anything drives a decent amount of cost into a part. Between design, prototyping, materials, hardware and jigs, there's a fair amount of investment. If I can get an order or about 10, I can cut costs set up fees etc at the laser cutter and getting the steel tube, hardware etc. .

Let's see where this goes I guess. It's Christmas season and all but if there's enough interest, I cam get a run of them ready to ship by the new year.

Regarding fishing the bolt, there's a simpler method. There is a way to fish the carriage bolt and plate down the frame with some string and a coat hanger.  

Thanks for the feedback.

Is the drawing to scale? The cross-member just looks a little small for it's length to my eye, but then it might be an optical illusion because the chain plate and receiver are not shown. The price sounds fair, especially if you are including the upgraded bolts. If I didn't already have a hitch, I'd certainly be interested. And I like the way you are ensuring compatibility for all flavours of B-body wagon.

buickwagon wrote:

Is the drawing to scale? The cross-member just looks a little small for it's length to my eye, but then it might be an optical illusion because the chain plate and receiver are not shown. The price sounds fair, especially if you are including the upgraded bolts. If I didn't already have a hitch, I'd certainly be interested. And I like the way you are ensuring compatibility for all flavours of B-body wagon.

It's to scale and should be within a few mm in width. The crossmember is 2.5" x 1/4 wall tubing. I'll be uploading a finished 3D model of version 1 later today. It likely looks different because Rebalc's design had the vertical plates biased toward the inboard side of the rails. I wanted to tuck the structure up along the rails for better exhaust clearance but the inner face is not very straight and compromises the design as you go rearward if you try to keep the vertical plates tucked up along the rail.

Here's the current design. I have the bumper pieces and side plates out for quote now. Once i get a better idea of those costs, I'll announce final pricing.
Total shipping weight should be pretty darn close to 47#

Ummm. If the cross bar is 2" x 2", and the receiver is the same size, how will a 2" x 2" ball mount fit in the reciever? Or did you mean 2-1/2" x 2-1/2" x 1/4" in your previous post?

buickwagon wrote:

Ummm. If the cross bar is 2" x 2", and the receiver is the same size, how will a 2" x 2" ball mount fit in the reciever? Or did you mean 2-1/2" x 2-1/2" x 1/4" in your previous post?

Yes, 2.5" 1/4 wall. I corrected my typo.

I assume you will ship these with some sort of hefty waiver where you're not responsible for damages, blahblahblah.

Glad to see these out there. I'll never tow again with my current wagon, but my next one might.

looks just like a drawtite,.

phantom 309 wrote:

looks just like a drawtite,.

Similar design, but designed from scratch. I had one on my 94 1A2 10+ years ago, always liked how it tucked.

Just a suggestion, but maybe a mounting bracket for 6 or 7 wire harnesses so we don't drill holes in the brand new hitch? wouldn't have to be heavy duty, but it would require some thought, as the harness connectors are about 3" deep. Maybe angled? I've seen that on some aftermarket hitches.

FarmingEngineer wrote:

Just a suggestion, but maybe a mounting bracket for 6 or 7 wire harnesses so we don't drill holes in the brand new hitch? wouldn't have to be heavy duty, but it would require some thought, as the harness connectors are about 3" deep. Maybe angled? I've seen that on some aftermarket hitches.

I've thought about that, as I will be doing a trailer brake controller in the future. It will be tricky to locate it in a protected area that does not hang below the receiver. I'll see what it looks like when the hitch is on the car, but I'm thinking one facing down might work. When there is no shank and ball in place, the cover would be protected vertically by the receiver tube, and when the shank is on a portion of it will likely hang lower and protect the mating connector. This is a first thought though.

I hear you on the drilling into a new hitch part. I had to do it on my Class V Curt hitch I put on my old Dmax.

Speaking of my old Dmax - here's a front mount hitch I built for it to maneuver trailers in the yard. This one was hand fab'd with some old 1/4" plate (hence the pitted surface) I had and a receiver tube I bought. Worked awesome. I totally forgot I built this last year.
The 79 Caprice makes an appearance here. This is after I blew up and removed the LS1.

OK, I know we are still hashing out the fine details, BUT, the line has to start somewhere...

I'm IN FOR ONE.

May I suggest that we all source the hardware locally, rather than trying to attach a bag of loose parts to the hitch or shipping it separately, might make life a bit easier



I vote for a round 7 pin plug mount, with cover, mounted horizontally, on the front of the cross bar. Out of sight and protected.
Drill and tap two 1/4 X 20  holes and use the bracket supplied with the 7 pin female plug.

Thanks, Paul

Count me in...let me know if/when you run a batch. Like the design.

I'm interested pending the plug mount

Sorry Red, the line was already started, you just got in it... I agree that it should be a 7pin mount as that seems to be pretty standard. I like the idea of the hardware coming with the hitch, but I don't have to worry about shipping.

Are we going to get an installation manual with this? May a utube video?

If it fits my OCC without major mods, I'm interested.......

Does it use the long-slot towing securement holes in the underside of the frame? On my wagon, the exhaust is just a pipe but turns out just behinf the spare well. Your design looks like it will fit

Regarding 7pin plug attachment, my Hidden Hitch did not come with any brackets. It did come with a plastic mount that attach to the main tube at an angle. Seems to work fine.

Wow. That is some serious work put into the design.

I said it on the other thread but I'll say it again, I'm in for a hitch. Rather have it now and find a use later.

Hey Beertestr,

Count me as +1 for the hitch.

Thanks everybody. My laser cutter is cutting the first set of pieces, and we'll be tweaking in the bend for the side plates in the next couple of days. I hope to have a prototype made up before Christmas.

So you guys want a beefy version of this? This is a generic Hopkins 7 way connector mounting plate.

That would suffice. I had to make a drop down bracket out of some chinsy tin metal. It holds for now, but could really use a solid mount

I have something like this:

http://www.etrailer.com/Accessories-and-Parts/Bargman/54-77-074.html

It accepts both a round 7-pin and a flat 4-pin. No need for adapters, I just plug into whichever one the trailer of the moment requires. Very handy.

Just a thought...

buickwagon wrote:

I have something like this:

http://www.etrailer.com/Accessories-and-Parts/Bargman/54-77-074.html

It accepts both a round 7-pin and a flat 4-pin. No need for adapters, I just plug into whichever one the trailer of the moment requires. Very handy.

Just a thought...

the Hopkins one I have has both 7 and 4 way connectors, but appears more compact. I put one of them on my Dmax when I upgraded the hitch. Let me mull on it a bit. I have a beefy bracket I can make up that also protects the connector a bit too.

Still may need the 6 round. I just carry the adapter that does 7 to 6 and 4 and covered

Yep, that's eggzackery what I was asking about, If one has some hand skills and tools, one can be easily fabricated. (Drill press, hole saw, drill bit's) Perhaps offering one as an option would be more appropriate.

Paul

Actually, the bracket you show would also work with a 4/7 wire unit: Etrailer Kit. I'd stick with some variant of what you show.  I was more thinking of pre-installed studs or tapped holes (or if you really want to protect the hitch from corrosion, an offset mounting bracket for the mounting bracket made of more lightweight steel (kind of like an inverted din rail). Not really looking to add more work for you, just trying to help the design to be flexible for varying needs.

I need a proper hitch for my wagon so I am probably in for this.  I would like to see the prototype though. Will this hitch design lock out the bumper shocks and make the bumper mount to the frame solid?

Progress pics, i made up a side plate for mockup out of thinner guage stock, just to check fit. I'm going to try a few tweaks but it's in the ballpark. My wagon has a fabbed up exhaust, I'll be tweaking the pipes to clear the hitch, hence the weird location of the pipe in the pic.




And a underside shot showing how the plates fit along the outside of the frame. Again, this is test fit with ~10gage steel, the real pieces will be out of 1/4" steel.

The drawtite hitch looks identical,. it has two tweaks either side of the receiver tube

NO RTR 7 wrote:

I need a proper hitch for my wagon so I am probably in for this.  I would like to see the prototype though.  Will this hitch design lock out the bumper shocks and make the bumper mount to the frame solid?

No, the shocks are unaffected with this design. No lock outs, or any modification to the bumper shocks.

phantom 309 wrote:

The drawtite hitch looks identical,. it has two tweaks either side of the receiver tube

I've been pretty clear that it was based on the Drawtite design, but I've designed it from scratch. FWIW it will have some Curt parts in it too.

I'd be in for a hitch - been overloading the class II I currently have...

Interested if this moved forward

Any chance of getting one to come out of the plate hole on a roll pan?

BigBlackBeaSSt wrote:

Any chance of getting one to come out of the plate hole on a roll pan?

I couldn't say for sure without having something to measure.

oldfriendabb wrote:

Interested if this moved forward

just got my wagon back after an unexpected engine swap and 2 transmissions. Weather permitting I should be test fitting parts this weekend.

beertestr wrote:

just got my wagon back after an unexpected engine swap and 2 transmissions. Weather permitting I should be test fitting parts this weekend.

Ouch!  Hope you got more power through the process.  Looking forward to hearing how the fitment goes.  Hoping to pull my racer with the wagon to the track soon.

Progress pics. We're going to try some bends in a few mins.

Edit: Resized to something less than 1M x 1M pixels.

Is there an emoticon for drooling?

Those are soooo nice...

buickwagon wrote:

Is there an emoticon for drooling?

Those are soooo nice...

How about...  :-)~~~0


or..

A little setback yesterday. The right side went on to the frame in a breeze. The left side was obscured by a partially collapsed bumper shock. I spent a little bit of time trying to get my Porta Power ram in between the frame and bumper and try to push it out, but it just was fighting me all the way. If my ram was about 1/2" shorter I would have been in great shape, but it wasn't. I'll be pulling the rear cover and bumper beam off and changing out the shock this afternoon.. Stay tuned..

After trying to push the absorber out with the porta power, it became obvious that would not work. As Murphy's law would have it, the top two bumper bolts were rusted up pretty good. The easy to get to ones were a breeze.
Following my luck, I found the bumper shocks to be different sedan vs wagon, so I'm goingnto cut and weld the wagon flange to the sedan absorber. Should be back in business tomorrow night. Right now, i have both end pieces on the frame and I slid the 2.5" tube in to eyeball the fit. It's in the hunt, but I'll save judgement for when I have the bumper beam and fascia back on to check the height.

Random pics of the absorbers pre mod.
.

Welding the bumper shocks may be extremely dangerous!

There is a strong possibility that the heated shock may rupture, especially right at the weld puddle. The pressure can blow molten metal into your face.

buickwagon wrote:

Welding the bumper shocks may be extremely dangerous!

There is a strong possibility that the heated shock may rupture, especially right at the weld puddle. The pressure can blow molten metal into your face.

You drill a hole in the side of the tube to vent the pressure. When you are done welding the end and the shock has cooled, you hit it with a quick plug weld. Done. I'll take pics.

Just an aside: I believe I would replace the shock absorbers with a solid (non collapsing) strut.

Tucking the bumper closer to the quarter caps, eliminating the filler plastic/rubber would, to me, improve the overall appearance, while not compromising safety. I believe that the only thing helped by the govt. mandated 5 MPH crash bumpers was the bottom line of big insurance

Paul

They'll help your quarter panels in an impact. That's what they do.

Ask me how I know.

(Actually, please don't.)