terrawombat

Come up to NJ with a large, enclosed trailer. Back it up to the gate at the Bristol Myer's Squibb facility in Pennington, NJ. Once a year, they round up all of the deer that have wandered into their site, and chase them along their fence line until they reach the only set of open gates, where they run out, usually in packs of 15-20. What awaits them on the other side is their imminent death from the hunters on the property, but if you want to save them and bring them down south, be my guest. All of the environmentalist blowhards have made them so protected in this area that I can't walk 100 feet without seeing a family grazing in a pasture. They're just a nuisance to me now.

Based on the calculations I've done I don't even know if those brackets would hold up in certain situations

Wow, those side brackets seem pretty wimpy for a winch mount. I figured they'd be a little more beefy like the mounts I've got brewing:

I spy the first set in your ZJ.

Not quite the same. The 5.9L Limited interior is a different grain of leather than the standard Limited. The e-brake handle, transmission shifter, and transfer case shifter are also covered in the same leather. So is the center console lid. I believe all of the fake woodgrain trim is 5.9L-specific, but now I'm just nit-picking :D

Those are Fey brackets with a Fey step bumper.

I know the feeling. My '01XJ has a very "loose" steering wheel with what seems to be quite a bit of side to side slop. My MJ is kind of the same way, but my ZJ is tight, no squeaks, no weird noises, just solid. I love the heavier feel of the steering and the car in general. And the 5.9L Limited interior is like I'm driving in a lazy boy recliner.

Well, depending on how poor you are, you may be able to have the court appoint you a public defender for free. I can't comment on how good a public defender would be, but it's much better legal representation than none at all. I suspect that your public defender and the prosecutor will just have a little chat, and work out some kind of plea bargain to give you a lesser charge, but you'll still have to pay a fine. A private defender (although it will cost you money) may actually try to get the ticket dropped entirely, but would also more than likely get you a plea bargain. Trust me, if you don't know what you're doing in there, your head will spin around and you're gonna have the book thrown at you. My friend tried to fight a parking ticket he got that he didn't feel was justified. He didn't know much about the local laws and only knew what he had seen in movies as far as trials are concerned. He made up a poster with photographs he had taken to show that his parking job was legitimate and a ticket was not warranted. He basically just embarrassed himself, wasted his own time, and still had to pay the fine. The judge didn't care and even laughed at him. The entire judicial system is a business - they just want your money. Townships have bills to pay and traffic fines generate a decent amount of revenue for them.

I would get a public attorney. If the cop who issued the ticket actually shows up, he will have legal representation, and they will absolutely own you in court and you won't stand a chance. Of the 100 cases I've heard about where people tried to represent themselves in a trial, 95 of them get smoked. The other 5 did a lot of homework and were well educated on state and local laws.

Rob, when can I come visit and get some measurements off that?

So it that because the female is too big or the male is too small? This is actually a good thing as it makes it much easier to buy the tubing stock. Just get 2.5"OD square tube with 1/4" wall thickness for the cross piece and the female receiver tube and call it done.

Your right. The cross pc is 2.5 inch O/D tubing. The "female" part of the receiver is also 2.5 O/D tubing with 1/4 inch wall thickness. The "male" part of the receiver (part with the ball) is 2 inch O/D tubing. Interesting information. I'll have to check my hitch out, but I was very confident that the female portion of the receiver was 2"OD. I was also measuring an XJ Class II hitch last week so I may have my dimensions mixed up.

My local place sells by the foot, cut charge too. Yea, I've got a couple places by me that do per foot too. But, it's always cheaper per foot if you buy the entire 20' piece. Problem is that 20 feet of steel doesn't fit too well on any of the trucks I have :D

I forgot to verify this on the Draw-tite hitch that I have, but I think that the long box tube cross piece is 2.5" square tubing. I know that the receiver tubing is definitely 2" square tubing, but I need to verify the wall thickness of that.

command trac just means it has a 231 transfer case. It does have the PRND21 mounted on the column, very strange unless it was added after market My old '86 2.8L/Auto had the selector display mounted on the column as well. That darn needle always kept breaking... My '86 also had the same paint job as the one in that ebay ad, but came with a red interior instead of black. Had it repainted all silver and it looked really sharp. Wish I still had that truck...

Good 'ole Von Mises. I fired up the built-in FEM in SolidWorks for the first time in years this morning. I had to LOL at how much faster and easier it is to program a finite element model than it is to do a CFD model with combustion. There's another fellow in my office that does all of our finite element modeling and I'm no longer going to feel sorry for him when he runs into a problem with something. I literally spend a week getting a CFD model to run right on an expensive computer set up for it. I had an answer with this receiver hitch in less than three minutes on my netbook.

The screenshot shows displacement, which is not necessarily a determination of a weak point, persay. It makes sense that the largest displacement in the model occurs directly in the middle. You won't see large displacements at the bolt holes because they are a pinned constraint and aren't allowed to move in the model. I have a lot of refinement that needs to be done to provide a much more realistic model and it's been a while since I've used this particular finite element modeling software, so I need a refresh my memory of all of its capabilities. I just wanted to throw something up so you can see how I'm doing my preliminary "testing" of the brackets. Ideally, what I'd like to do is insert a ball receiver into my model and place the artificial trailer loading on the ball itself. Due to the increased length of the ball receiver the hitch will have a greater tendency to want to "twist" and should show a change in the stress concentrations in the model.

The highest stresses occur around the bolt hole furthest towards the rear of the truck. The above screenshot shows deflection and I turned the "deformation" factor up WAY high because it looked goofy. The actual total maximum deformation is less than a tenth of an inch. I just did a static load of 1200 lb. on the tongue, which is the maximum recommended tongue weight for a Class IV hitch (this is designed to mimic a Class III hitch). Even with that loading, the maximum stresses were well under the yield stress for A36 steel. I'll run some more simulations when I get home and I'm actually near a computer with a 23" monitor, rather than on this 10" netbook riding in a car!

I bent it!

I'll have to send a prototype out to Jim with the requirement that his certified testing is caught on camera. Yes, the version I modeled included the rear shackle bolt for a SWB MJ only. This will still fit on a LWB, it'll just have a goofy-looking extra hole. One thing I was thinking about when I was putting the assembly together in CAD is that installing and removing the hitch is going to be kind of annoying since you'll have to back out on both shackle bolts to get the hitch to bolt up to the frame. You'd have to be real careful not to back them out too much! Also, I'm going to do some testing myself - in the form of finite element analysis. Going to place some constraints and loading conditions on my model and see what kind of stresses we get and where the supposed failure point would be.

Haha, you guys know how to keep me moving! I'm currently on a business trip for work in Virginia, about 5 hours away from my shop. Luckily I brought some of my project files with me to work on them in the 10+ hours of time in the company car. To answer your requests, I can tweak the model to cut out a hole for 2" square tubing sometime today and I'll post up a picture for your approval - shouldn't take me long. Now, thinking about this from a production standpoint - it would be cheapest and, for me, easiest if I provided the bare cut side plates and safety chain plate and then the buyer bought the 2" square tubing, angle iron, and hitch receiver tube. I would obviously have to put a giant disclaimer on the plates stating that they are in no way rated for any load whatsoever. Trailer hitches go through testing to become "certified" for the class they were designed for. I haven't ever seen what the cost of such a test would be, but I can only assume it's not something I can afford. I will, however, build a prototype model for myself and haul around the heaviest trailer I can find. My father has a semi-enclosed steel horse trailer that has got some good weight to it. Or I can clean off his flatbed trailer, load up my ZJ on it and test it that way. This is about the extent of the testing that I can do! I'll update the thread when I have something interesting to show.

I do have to ask now that you said you've been away from your vehicles - where did you find such accurate dimensions of the bolt holes on the MJ/XJ frame? I checked my '92 FSM and my '01 FSM and the only frame dimensions that I saw were some very basic point-to-point measurements which could maybe be used by a frame straightening guy to get a wrecked frame back into alignment. I didn't see anything in the way of hole spacing so I assumed you were taking your own measurements. I went through four cardboard "prototypes" last night getting my hole spacing right, but if there's a dimensioned frame drawing out there, that would have saved, oh, three hours LOL

Echo...echo....echo...echoooooo