THIRD broken swing away bolt!!!

[RedAllison]

Today as I pulled RDWII out of the garage to begin prepn her for the Labor Day wknd I checked the bolt on the swing away tongue and ONCE AGAIN the :cuss was BROKEN!!! That is now THREE bolts, exact same spot, all 3 Grade 8 that have broken since this rig was built for me in summer 2007. I don't even use the GDMFPOS swing away as I have room in my garage. The first time it broke I thought "well musta been a bad batch from the factory", I told Boatmate about it and they asked for the bolt. (Which I DIDNT send them!) The slack in the swing away has always turned me off, even before I bought this one. So when I replaced the broken bolt the first time I went to my local Fastnall store and bought several of the right Grade 8 bolts and replaced not only the broken bolt but the SS quick pin with a bolt as well. I thought that would fix it, those 2 G-8s should hold the Space Shuttle at WOT!

Then again, THAT replaced bolt broke a few years ago! :help I threatened to have the whole thing welded up but just never got around to it so I simply replaced it once again with one of the G8s I had from the few I bought at Fastnall, stuck the SS pin BACK in the port side out of curiosity and let it ride. Alls been fine and well UNTIL this afternoon. I haven't had time to use the boat since Clifton so I know that's the last time it was used. I usually check it daily during use and KNOW I checked it a few times during the rally so it more than likely broke on the way home.

Same thing everytime, they are snapping where the threads start so obviously it's a sideload issue. Like Todd Bucknell said, "Just like a stress riser in a blade, that's the starting point since it's the first "cut" in the bolts length". I realize G8s have zero flex before they bend or snap, but DAMN I can't see how there's enough leverage there for that but obviously there IS!

I'm on my last G8 bolt now, stuck it in and tightened it all down for the wknd. But by next spring I plan on having this SOB welded and painted up. I'm DONE with a "link" in the trailer that I never have trusted nor desired in the first place!!! :furious

 

[allisonjr]

Would maybe changing to a different thread type while still using the grade 8 bolt be an idea. If its a coarse thread maybe try a fine thread just an idea I don't know if it would help any

 

[xb03fs]

Some times harder is not better when it comes to metal as it is more brittle than softer metal which may bend but not shear

 

[jimbob88]

why are you using a bolt with threads? only swing aways I've ever seen, it's just a big pin with a hole thru it to put the keeper (cotter?) key thru so it can't pop up & out.

 

[champ198]

The pin with the cotter pin pulls out and is fine. The hinge bolt is what Jim is talking about.

 

[jimbob88]

thanks duane, was confused

 

[SLOmofo]

Some times harder is not better when it comes to metal as it is more brittle than softer metal which may bend but not shear

Yep, I agree! The pin hasn't broken, it's probably much softer. Put a pin on both sides.

 

[wasmeneh]

Mine's made a little different than yours but it has some little rubber nubs that have to be compressed when closed. It kind of takes the slop out and there is no movement of the movable tongue when in the extended mode.
Mike

 

[2fast4mom]

Mine was built in 2007 as well, and is dual-axle and is red. :laughing

It hasn't broken a single bolt.

I think it was Archimedes that said "Give me a lever and I can move the world"....or break a grade 8 bolt. The levering force that is breaking that bolt is what needs to be determined. If not, your weld may crack as well unless you weld the whole affair all the way around.

Go out and get a regular 6-point bolt with coarse (or fine) threads that allow the solid portion of the bolt to protrude through the bottom of the arm assembly. Take up the "slack" between the threads and the bottom of the arm with a washer or washers (this bolt doesn't have to be real "tight", right? Since it's a pivot point). A washer at the bolt top would be a good idea as well.

Put a nylock nut on the bolt, tighten up to the point where the arm still will move but doesn't have slop, and hit the road. Periodically, remove the bolt and check for bends (roll it) and/or "scribe marks" that will be telltale of where the shear force is coming from.

By doing this, #1 it likely won't ever break again, and #2 you will gain insight into the mechanism of the failure mode.

Somehow the end of that bolt is being levered. HARD. Grade 8 bolts just don't break without extreme force. I do agree that the threads are the beginning of the crack each time.

This "experiment" may yield results valuable to all other swing-away owners.

 

[Allyfishing]

I've often wondered about this bolt after reading RA's post the first time his broke. So with my 2+2 trailer (2008 year) I used to give that bolt a shot of WD40 now and then. I have to use my swing away.

Now with my 2013 Pro trailer I do the same WD40 thing but I also notice that I have a bit of up and down movement of the swing away portion of the tongue with the bolt and pin in it. I can lift it up and down with them both in.

there is no way to tighten down the bolt because of the welded on metal tabs that the bolt goes thru. so no way to draw up the slack on the bolt side like Lou suggested. And no way to add washers either.

RA do you lubricate that bolt ever??

 

[2fast4mom]

So..the bottom of the swing-away piece is threaded?

 

[Allyfishing]

Correction, mine looks like RA's. Plate on top and bottom where the bolt and pin go thru which in turn go thru the "sleeves" . My up and down play is due to the slight gap between the "sleeves" and the upper and lower plates that the bolts and pin go thru.

There's no way to cinch it down any tighter

No, the bottom is not threaded.

Jim, when your bolt and pin are in place can you lift up on the coupler and get up and down play or is it tight?

 

[RedAllison]

Jim, when your bolt and pin are in place can you lift up on the coupler and get up and down play or is it tight?

YES Craig I can "lift" the front of the coupler maybe 3/4" when its bolted and pinned. THAT is what is snapping the bolt I believe! :banghead

 

[Allyfishing]

Yup, that may be doing it. I'll have to check today and see if I have that much movement. I have to fold the tongue over to get my rig in its place where I store it and each time I go to hook back up I actually have to lift the coupler up slightly so the pin drops in.

also I was wondering if the height at which we tow the rig has any affect on the stress of that bolt. My hitch height puts the trailer in a very slight incline to the bow of the boat. Any higher I can see where it would put all that downward force on the attachment point aka. bolt and pin!!

I assume you have contacted Boatmate so what do they say about it??
That is if you even got to speak to someone???

 

[fnshrmaster]

My dealings with Boatmate have been less than desirable.

The next trailer I buy will not be a Boatmate.

 

[SmallJaw]

My swing away has hardly any play in it. The removable pin always works its way up to the top most position but so far I have not had any problems. I will be removing the bolt today though and looking for any wear. I'd sure hate the trailer going crazy on the highway. :shock:

 

[fasteddie]

My dealings with Boatmate have been less than desirable.

The next trailer I buy will not be a Boatmate.

I agree I was very unhappy with their customer service!

 

[K.Kiser]

Seems like too much slack for any common pin to survive long term, and I doubt any pin is gonna restore your confidence at this point... I'd find the a very competent welder in the area and let him do some magic... I'd think a real deal professional welder would know exactly what how to fix that frame back to 100% while making it look original and intentional.. If you could pen down a car chassis builder or a reputable utility trailer manuf. to do some work on it would be real nice.. Those guys tend to be a bit above average on straightness, fitment, grindwork, and laying bead..

 

[SLOmofo]

Never had one of these, but. Before you weld it solid. Is the inside of the tube on both pieces open and the same size inside? If so take the next size smaller tube and slide it into both pieces, should fit well. Then drill and tap the trailer and tongue and bolt it, the bolts when tightened will take up the play.

 

[GotMyAlly]

The up/down play is the problem. When Jeff had your boat, we compared it to mine in my driveway. Yours has A LOT of play compared to mine. That bolt is having two loads applied. A side load, plus a clamping force.