Hitch pin replacement with bolt-safe?

[bluedog225]

I have to use an 8 inch extender to get my towing ball far enough away from my vehicle to tow. For some reason, the DrawTite class 3 ends while still under the Ford van bumper (E250).

It all has a pretty good amount of play in it. Someone suggested a bolt of the same diameter as the hitch pin, then tighten it down to eliminate the play.

Would this be safe? Does anyone know, with certainty, that a Grade 8 bolt of the same diameter would be stronger than (or as strong as) a hitch pin?

I hate to mess with items designed by engineers for a specific purpose on a trial and error basis. Especially when the safety of others is at stake.

Thanks
Tom

[Woxbox]

I don't know, but if you tighten it down to remove the play, you'll be crushing the tube, making it near impossible to slide the hitch in and out, won't you? I always thought play was built into that equipment to allow for a bit of dirt and rust over the years.

[dmg]

You probably have a 5/8" diam. pin ? Grade 5 has a shear rating of 23,010 lbs., grade 8 has 27,920 lbs.

Back in the 70's, I loaned my Ford full size wagon/car trailer to a buddy to go to the NHRA Indy Nationals. On the way home they got rear ended by a drunk being pursued by State Police. Idiot was going 100 mph, my buddy, about 65 mph. Buckled the trailer tongue, threw the race car off/over the guardrail. Never did much at all to the hitch/station wagon.

Seems like you should be able to test a hitch pin with a hack saw blade or file, and compare to the two bolts. Woxbox is correct though about clearance for dirt/rust. Tightening the bolt might be counter productive.

Dave

[Canoeyawl]

Don't worry about the play, it's normal.
I always use a bolt, just snug it up and hit the end threads with a hammer so the the nut can't remove easily - (this, more for theft prevention than anything else)

[bluedog225]

You probably have a 5/8" diam. pin ? Grade 5 has a shear rating of 23,010 lbs., grade 8 has 27,920 lbs.

Back in the 70's, I loaned my Ford full size wagon/car trailer to a buddy to go to the NHRA Indy Nationals. On the way home they got rear ended by a drunk being pursued by State Police. Idiot was going 100 mph, my buddy, about 65 mph. Buckled the trailer tongue, threw the race car off/over the guardrail. Never did much at all to the hitch/station wagon.

Seems like you should be able to test a hitch pin with a hack saw blade or file, and compare to the two bolts. Woxbox is correct though about clearance for dirt/rust. Tightening the bolt might be counter productive.

Dave

Thanks all. Yes, 5/8. Those shear numbers on the #5 and #8 were what I needed.

I was thinking that I would be clamping, not crushing, given the thickness of all the steel involved. With some grease or plastic shims, I wouldn't think removal would be too tough. Might require a few taps with a hammer. I plan to leave it on 99% of the time anyway.

Just random google gives me advertisements of 5/8 pins with shear strength of minmum 30K lbs. Some claim to he "high shear" at double that for those who "are tired of bending their 5/8 pins."

Based on that, it seems like I am downgrading the safety of my rig using even a #8 bolt. I also don't know how the hardness of the #8 will affect actual performance with shock loads. I read they are subject to sudden failure without prior distortion.

It's one of those things where it may be fine and work for lots of people but I just can't get comfortable with it based on what I know so far.

I seem to recall a hitch pin designed to be tightened. I'll look some more.

Thanks again.

Tom

[Ross M]

IMO using bolts in shear is sometimes acceptable, but only when the threaded portion is well outside of the load path. Otherwise:

1. The bearing area is reduced to the line contact along the thread crest and whatever deformation occurs;

2. The effective pin diameter is reduced to the root diameter of the thread;

3. A stress concentration is produced at the thread runout.

Then there is the issue of combined loading - tension from the "clamping" coupled with shear from the working load.

Also beware that bolt shanks are frequently quite a bit smaller than nominal size (and possibly smaller than the shear pin) yet the majority of the strength comes from the outside diameter.

All that said I am sure that many people get away with it, more or less.

[Gold Rock]

The relative strength of the bolt aside, what you should be concerned about is the affect of extending the drawbar too far from the vehicle. You're creating a lever arm which increases the strain on the hitch mounts. How long is too long? Dunno. If you've got a full sized class III or even a class IV under there and you're pulling your 12 foot rowboat around, probably not much to worry about. But if you're at or near the max capacity of the hitch without extending the drawbar, be aware.

[Thorne]

By extender, do you mean one of these?
http://www.thehitchstore.com/images/imgD-180.jpg

Just for my information, would a SS bolt have any greater or lesser shear strength than a stock mild steel bolt?

[Canoeyawl]

I suspect that the "shear rating" posted above was calculated at the minor thread diameter, which is about 1/2".
The replacement bolt should be selected so that no threads are inside the tube. The steel used in a grade 5 bolt will be as good or better than the "pin"
(I use a grade 5, they have different yield characteristics than a grade 8 - They are more malleable. In fact a 316 SS bolt is a "tougher" bolt in regard to load cycles before breaking failure)

[Lewisboats]

Just drill the damn thing out and put in a 3/4"

[Bill Huson]

The hitch folks make gizmos to quell drawbar rattle. Other method, turn up the stereo! I did use a bolt for a drawbar when I lost the hitch pin. Not squish the receiver tight, just in there with a nyloc nut. Bolt was in there so long I had to hacksaw the frigging thing off when it became necessary to change drawbars. It was a mild steel bolt just like the mild steel hitch pin. I wouldn't use a grade 8.

[bluedog225]

Yes, that's the type of extender I have. Per specifications, I have reduced my load (tongue of trailer or basket) from total of 500 to 333 and my total towing capacity by 1/3 as well.

Still well within limits on total towing (E250) but will watch tongue weight with cheapo bathroom scale.

Thanks all. It sounds like stay with pin, or go with #5 bolt but make sure threads clear the hitch. Or go with 316 stainless.

Or just ignore it.....;)

[py]

A lot of hitches over here have a nut welded to the top corner of the receptacle-that is tightened down on the tongue to stop rattle.

[bluedog225]

A lot of hitches over here have a nut welded to the top corner of the receptacle-that is tightened down on the tongue to stop rattle.


Never heard of that. Mind posting a pic?

[Thorne]

Euro hitches are quite different from US models, so much that works on them won't apply to our hitches.

http://eurohitch.es/images/Phaeton.jpg

[py]

Still haven't worked out how to post pics-but here's link which shows the concept pretty well
Phil
http://www.ezimotow.com.au/faq.htm

[bluedog225]

Thanks. That's pretty smart. I wonder why we don't do that? Doesn't seem like it would make a bit of difference to the capacity. Easy enough to drill and cut the threads.

[Woxbox]

Actually, I don't mind a bit of noise from the trailer. It reminds me that it's back there.

[hikingchrs]

I find my hitch is noisey when I don't have enouph tongue weight should be about 10% of trailer weight.
Chris

[MiddleAgesMan]

Proper bolts aren't made of mild steel, except perhaps some crap from the Third World.

Grade 5 bolts should be adequate but unnecessary as stated above. It won't eliminate wobble without crushing the square tube.

Grade 8 fasteners are especially high strength steel, intended for a single use. You torque grade 8 to specs and if you ever need to remove it you replace it. It cannot be safely torqued repeatedly.

In another life I worked for a company that made wingwall cranes for the US Navy. Every critical fastener was grade 8 and we only made use of them in a final assembly--single use, then replace with new if the assembly ever had to be taken apart.