Help please! Jackknife = trailer & chassis repair

[squizzyhunter]

Help please guys.
I'm up the cape at the moment (Bamaga) and made a stupid mistake and jackknifed the trailer which has sheered the bolts off the "draw pole" to the lunette and bent the rear bumper/ crossmember.
Please see pics
116963116964116965116966116967

[squizzyhunter]

So for the trailer
Do the bolts need to be hardened steel? I'm assuming so but unsure what grade. What have other people used, cut heads off some bolts and welded them in or cut up some threaded bar?
If so what size as I'll probably have to get some sent to the post office here as limited options to source up here.

For the bumper do you think it can be pulled out and used or will it need to have some plate welded to it?
And recommendations for how to straighten it wolf be great as all I can think of is huge breaker bar through the pintle..,.

There is a workshop here but I can also lend a welder from a mate up here.

Dam what a stupid thing to do....

[JDNSW]

From the pictures, I would say that the cross member is OK as is (until back to civilisation), although if possible I would replace the bolts, at least on the left side. Long term, it looks very like a replacement cross member to me!

The trailer, I can't really comment on as I have no experience with them.

John

[alien]

I'd be inclined to head to one of the local workshops to get them to have look.
Cape York Mechanical Services - Cape York, Queensland Australia (http://www.capeyorkinfo.org/cape_york_mechanical_services.html)
They may have the bolts on hand you want as I'm sure your not the first to do this.
The rear bumper is also a cross member for the chassis so have look over the full width for damage, not just at the hitch bolting points.
The force it took to bend things needs to be replicated to put it back, a side pull may help but you need to make sure you don't make things worse.
In situations like this a second or third opinion is well worth seeking as pictures while helpful don't always tell the full story.


Let us know how you get on.

[Blknight.aus]

the ring has failed as intended,

cut of the remaining damaged bolts and threaded rod to get the link off, check it for damage

grind off the remains of the sheared bolts and then using some suitably long bolts with the heads cut off weld them back in place and secure with new nuts.

leave 2 of the bolts in place so you can use the lunet as a template to mount the replacement bolts, weld them in then grind off the remaining 2. this ensures the new bolts are correctly aligned.

[Tank]

I'd be inclined to head to one of the local workshops to get them to have look.
Cape York Mechanical Services - Cape York, Queensland Australia (http://www.capeyorkinfo.org/cape_york_mechanical_services.html)
They may have the bolts on hand you want as I'm sure your not the first to do this.
The rear bumper is also a cross member for the chassis so have look over the full width for damage, not just at the hitch bolting points.
The force it took to bend things needs to be replicated to put it back, a side pull may help but you need to make sure you don't make things worse.
In situations like this a second or third opinion is well worth seeking as pictures while helpful don't always tell the full story.


Let us know how you get on.
I would use high tensile bolts and cut the heads off to replace the broken ones, if you can get hold of a Porta-power and brace it against an inner crossmember that you could pack and support with hardwood timbers you would probably be able to jack the rear crossmember back to near it's original possy. Or maybe use a High lift Jack or a hydraulic jack that will work on it's side, just be careful if you do this that the point your jack is pushing from is stronger and won't move when you start jacking the back out, good luck, Regards Frank.

[roverrescue]

The trailer looks readily repairable with a grinder and a welder and a few bolts
If the fella at the workshop has no bolts ask around at a few build sites
Four M12 concrete embedded studs would work perfectly

Ramset Australia (http://www.ramset.com.au/product/detail/3/chemset-anchor-stud)


How much trouble is it to remove the tow hitch - id be wanting to clean and inspect that hitch for cracking before towing the PDR
With new bolts the twisted rear cross member is unlikely to be troublesome

If only you were 800km south the shed here has everything to square that mis-hap up???

Steve

[stealth]

I did a similar thing on the rear of my 130 a while go. I also have the same pintle. I put an eight foot piece of gal pipe the right size into the pintle and gently eased it back straight. The rear cross member is only made of mild steel sheet metal and will give. Won't return perfectly as you have stretched the metal but you will live with it. I assume your pintle is attached with high tensile bolts so they should be ok.

[squizzyhunter]

Awesome thanks for the info guys! I think I'm going to have to bite the bullet and get the workshop to weld them as I don't want clutter my mates driveway for days if I can't find the bolts in time.

Thanks for the offer Steve, sounds like Cooktown is a good place to break down.

[Wallaby Ted]

The first mechanical shop in the link is run by a member on here marko66. He was at Adelaide River in the NT until he moved there.


Richard


I'd be inclined to head to one of the local workshops to get them to have look.
Cape York Mechanical Services - Cape York, Queensland Australia (http://www.capeyorkinfo.org/cape_york_mechanical_services.html)
They may have the bolts on hand you want as I'm sure your not the first to do this.
The rear bumper is also a cross member for the chassis so have look over the full width for damage, not just at the hitch bolting points.
The force it took to bend things needs to be replicated to put it back, a side pull may help but you need to make sure you don't make things worse.
In situations like this a second or third opinion is well worth seeking as pictures while helpful don't always tell the full story.


Let us know how you get on.

[strangy]

I recall Marko66 (aulro member) is running the recovery service and workshop in Bamaga.
You should at least get some LR know how even if the he has to get parts in for you.

[MR LR]

The lunette bolts are 3/8" UNC high tensile, I would recommend replacing with 3/8" UNF high tensile, any competent hardware store should have them, or any fasteners store will. As others have said they are literally bolts with the heads cut off, those trailers are very agricultural.

Looks like a Perentie rear cross member? If is is they are fairly heavy RHS, remove the pintle and have a look at what's actually damaged, has it just pulled the nuts through or is the RHS bent? I'd suggest just plating it on the inside if needed and straightening the rear edge, then re-installing with new 1/2" UNF high tensile bolts. But with the pintle still installed I can't see whats actually mangled.

Stripping it all down would be my first step.

[squizzyhunter]

The lunette bolts are 3/8" UNC high tensile, I would recommend replacing with 3/8" UNF high tensile, any competent hardware store should have them, or any fasteners store will. As others have said they are literally bolts with the heads cut off, those trailers are very agricultural.

Looks like a Perentie rear cross member? If is is they are fairly heavy RHS, remove the pintle and have a look at what's actually damaged, has it just pulled the nuts through or is the RHS bent? I'd suggest just plating it on the inside if needed and straightening the rear edge, then re-installing with new 1/2" UNF high tensile bolts. But with the pintle still installed I can't see whats actually mangled.

Stripping it all down would be my first step.

Cheers thanks for the info! I am getting the local welder to weld them up but I just ordered 100mm x 10mm in 8.8 fine thread in black with nylocks from a bolt shop in Cairns, getting flown up tomorrow. Do you think that will be sufficient? I know I'm over thinking this one but would like to do it right the first time around.
Cheers
Ty

[MR LR]

Cheers thanks for the info! I am getting the local welder to weld them up but I just ordered 100mm x 10mm in 8.8 fine thread in black with nylocks from a bolt shop in Cairns, getting flown up tomorrow. Do you think that will be sufficient? I know I'm over thinking this one but would like to do it right the first time around.
Cheers
Ty
That will be even better as 10mm is slightly bigger, may need to clearance the holes but that's no biggie.

[squizzyhunter]

That will be even better as 10mm is slightly bigger, may need to clearance the holes but that's no biggie.

That was the plan but was second guessing after Dave was saying that it is supposed to be the point of failure when things go ass up. I suppose that just fraction more size should not make it too much stronger.

[MR LR]

That was the plan but was second guessing after Dave was saying that it is supposed to be the point of failure when things go ass up. I suppose that just fraction more size should not make it too much stronger.
I don't necessarily agree that it is an engineered failure point... more like **** poor design, but that's just me being overly critical.

[squizzyhunter]

I don't necessarily agree that it is an engineered failure point... more like **** poor design, but that's just me being overly critical.

Haha yes I suppose that's fair 👍

[Blknight.aus]

I don't necessarily agree that it is an engineered failure point... more like **** poor design, but that's just me being overly critical.

you do know that the ADF used to teach people to drive and reverse trailers right?

I've seen people that cant reverse a trailer without jacking it and busting up the draw bar and the rear cross,,,,, wait a second.....

:twisted::angel::wasntme:


Its bolted on for a few reasons.

the bolts break off and they are easier to grind off and weld on than welding the link on.
when the link wears its easier to unbolt one and bolt on its replacement

[MR LR]

you do know that the ADF used to teach people to drive and reverse trailers right?

I've seen people that cant reverse a trailer without jacking it and busting up the draw bar and the rear cross,,,,, wait a second.....

:twisted::angel::wasntme:


Its bolted on for a few reasons.

the bolts break off and they are easier to grind off and weld on than welding the link on.
when the link wears its easier to unbolt one and bolt on its replacement
I'm not disagreeing that that works... that's how I suggested he repair it also :wasntme:

But I highly doubt it was designed like that, never seen a design brief that says "make sure the hitch is easy to snap off!"

Willing to be proven wrong, but anything else is here-say.

Having built a few trailers though, and worked on number 5's, I think it's a crap design.

We have a very early box trailer on the farm (Ford V8 wide-5 stud pattern to boot) and it has a wooden draw bar, doesn't mean it was designed like that to self detach if your load incinerates itself :p

I can't believe people can't reverse trailers, it's so easy... although I did have pedal cars with trailers as a kid :D

[weeds]

I can't believe people can't reverse trailers, it's so easy... although I did have pedal cars with trailers as a kid :D


Woohoo, somebody else that doesn't make mistakes.....I don't believe the OP has stated the sequence of events but to do that damage I'm betting there is more to the story apart from not being able to reverse a trailer. Given he is up the cape I assume he has had to reverse the trailer many times during his trip.

a few years ago I jumped into my car and totally forgot the trailer was hooks up, hit reverse and two seconds late the trailer had imbedded itself into the passenger side......I rate my reversing skills when j remember there is a trailer hooked up.

Reversing a trailer is easy with practice and the opportunity.

[Aaron IIA]

The lunette bolts are 3/8" UNC high tensile, I would recommend replacing with 3/8" UNF high tensile

The lunette bolts on my no. 5 trailer are 3/8 UNF with nyloc nuts. They appear to be the original bolts. Six 3/8 bolts is certainly strong enough, considering that the pintle hook on the vehicle that originally towed these trailers, a SIIa GS, only has four 3/8 bolts holding it on.

You appear to have a non-rotating pintle hook. When towing a trailer with a fixed lunette, such as a no. 5, you need a rotating pintle hook, especially when offroad.

Aaron

[The ho har's]

Marko66 is a land rover recovery bloke in Bamaga find him

Mrs hh:angel:

[squizzyhunter]

I suppose criticism is warranted in this case. I'm usually not completely incompetent but definitely was the case here though unfortunately.... Only had a couple hours sleep as was fishing from 3am (was the case for the whole weekend)drove into town ordered some shocks (snapped my rear) and just coming out of the drive I was on autopilot and thought I saw the trailer arcing to where it was supposed to be without actually having a proper look. So yes it was a simple case of incompetent f wittery in this case unfortunately.

[squizzyhunter]

Was one of those days really, all I caught all morning was 1/3 of a queenie117008

[squizzyhunter]

As for the locking lunette I modded this one to rotate. Ideally I would love a rotating pintle as that's what has been advised (not sure if was a case of safety or just standardisation for the adf to go with the rotating pintle and locked lunette) but couldn't find a decent one so it's the rotating lunette for now.

[squizzyhunter]

Marko66 is a land rover recovery bloke in Bamaga find him

Mrs hh:angel:

Had a quick chat with him last week seemed like a good bloke. ordered some shocks through them but he is down in cairns at the moment.

[MR LR]

The lunette bolts on my no. 5 trailer are 3/8 UNF with nyloc nuts. They appear to be the original bolts. Six 3/8 bolts is certainly strong enough, considering that the pintle hook on the vehicle that originally towed these trailers, a SIIa GS, only has four 3/8 bolts holding it on.

Aaron

Still a crap design...

My reversing comment was not directed at your Squizzy hunter, more in general.

[Blknight.aus]

Still a crap design...
.

Ok,

Proove it.

Whats both simpler and better?

[Aaron IIA]

Ideally I would love a rotating pintle as that's what has been advised (not sure if was a case of safety or just standardisation for the adf to go with the rotating pintle and locked lunette)

It is a safety issue. If you jacknife with a rotating lunette and a fixed pintle hook, the lunette can drop down and hang from the pintle hook. When you try and straighten up, the lunette may not right itself properly, resulting in damage to the lunette mount, pintle hook or vehicle rear chassis. Did your damage occur from jacknifing the trailer too far, or when you attempted to straighten up? Which side of the car was the trailer when the damage occurred?

Rotating pintle hooks have a locking mechanism so that they can also be fixed. The mechanism is sometimes missing.

Aaron

[squizzyhunter]

It is a safety issue. If you jacknife with a rotating lunette and a fixed pintle hook, the lunette can drop down and hang from the pintle hook. When you try and straighten up, the lunette may not right itself properly, resulting in damage to the lunette mount, pintle hook or vehicle rear chassis. Did your damage occur from jacknifing the trailer too far, or when you attempted to straighten up? Which side of the car was the trailer when the damage occurred?

Rotating pintle hooks have a locking mechanism so that they can also be fixed. The mechanism is sometimes missing.

Aaron

Cheers Aaron, I think that may have been it as only heard a hideous clunk when straightening. The trailer was out to the left and the left gave out. Makes more sense now as I was scratching my head wondering how it sheered that way. Lucky it was only low speed driver error😬
Anyone have a rotating pintle they would be willing to part with???

[MR LR]

Ok,

Proove it.

Whats both simpler and better?
Literally every design that superseded that is better...

Do you define simpler as "agricultural" or "elegant, clean design"?

I'm gonna stop now before I offend a few people with some hideous vehicles :wasntme:

[MR LR]

Ok,

Proove it.

Whats both simpler and better?
Literally every design that superseded that is better...

Do you define simpler as "agricultural" or "elegant, clean design"?

I'm gonna stop now before I offend a few people with some hideous vehicles :wasntme:

[squizzyhunter]

117108
Trailer back on the road

[squizzyhunter]

117109
Chassis not so great

[MR LR]

That could be plated over once any high points were bashed in. Do the bolts go the whole way through? What's the inside of the cross member look like?

[squizzyhunter]

That could be plated over once any high points were bashed in. Do the bolts go the whole way through? What's the inside of the cross member look like?

Yep bolts through to the other side, the inside has the same bend unfortunately....