PDA

View Full Version : Yonnee & other trailer gurus - coupling issues



monkeyrelish
17th Jul 2010, 05:41 PM
Hi Guy's

I have a quick couple of questions. I picked up my new tinny today and brought it home where I discovered that it was a real PIA to get off the tow ball.

It looks as thought the previous owner has had this problem also as the end of the draw bar is a little mashed.

The end of the draw bar is fouling up on the tongue and getting jammed. It seems OK on perfectly level ground but any slope and there almost no hope of un-coupling the trailer.

I am thinking that part of my problem is that the angle of the draw is too raked when the trailer (Redco) is hooked up the Nissan (4WD).

I have attached a couple of pics to help explain.

I am interested to know if I can cut the draw bar back a little and (possibly even on an angle), if necessary would a strengthening plate welded to the end of the draw bar to help eliminate and crushing effect of the bolt if it is too close to the end of the bar.

The centre line of the bolt is approximately 30mm from the end of the draw bar.

I could turn the tongue upside down but I thought that it may then be too low.

Any help is appreciated.


Cheers


http://i921.photobucket.com/albums/ad59/monkey_relish/Boat/IMG_45901.jpg
http://i921.photobucket.com/albums/ad59/monkey_relish/Boat/IMG_45891.jpg
http://i921.photobucket.com/albums/ad59/monkey_relish/Boat/IMG_45911.jpg
http://i921.photobucket.com/albums/ad59/monkey_relish/Boat/IMG_45881.jpg

pipeclay
17th Jul 2010, 07:13 PM
No nothing about how to remedy your problem apart from attaching a new larger mounting plate for your coupling,have you tried removing your towbar tongue and turning it upside down and re mounting the ball.
It looks from the pictures that it is on an angle and the trailer draw bar is on a similar angle,turning it over may make the 2 flatter with less angle.

Bazzmate
18th Jul 2010, 08:23 PM
If turning the toungue down the other way is not an option (e.g. too low or still hard to get trailer off), I reckon you could get away with cutting back a section of the SHS like I've shaded in your photo (cut the same both sides of course) but leave the welding of the safety chain in tact. If you have concerns about the bottom cut edge of the SHS getting too close to the bolt at the bottom, you could buy a shorter bolt and bolt the coupling to the top of the SHS only, (instead of all the way through as it is now).

If getting the trailer off is still a problem after that, (Plan B) you will definetely have to go the shorter bolt as mentioned above and relocate the chain a bit further back to allow you to cut a little bit extra metal out.

If you need to drag the welder out for 'Plan B' you may as well just weld a coupling plate on top to get your SHS far enough away from the toungue.

Anyway, wait and see what others think.
Cheers

Yonnee
19th Jul 2010, 06:42 PM
Bazzmate's hit the nail on the head. There's no reason why the coupling was mounted as far back as it was. You have three options; weld another plate on... elongate the holes and move the coupling forward (highly NOT recommended)... or trim the drawbar down as Bazzmate has shown. I would just cut it off square back to the safety chain link. (try not to take too much of the chain's weld.) You don't have to worry about a crush tube, just poke a shorter bolt through the coupling and put the nut and washer on inside the SHS.

danielhobby
21st Jul 2010, 12:07 AM
is it an optical illusion or is the top flat surface of your tounge parallell to the ground?it looks like the top of the towball is "leaning forward" a little and i have that situation with one of my tow tongues and its a fair p###k to get the trailer off if the vehicles are on a hump of any sort.

Yonnee
21st Jul 2010, 09:18 PM
is it an optical illusion or is the top flat surface of your tounge parallell to the ground?it looks like the top of the towball is "leaning forward" a little and i have that situation with one of my tow tongues and its a fair p###k to get the trailer off if the vehicles are on a hump of any sort.

In the words of Grandpa Simpson, "...a little from column 'A', and a little from column 'B'..." The towbar hitch tongue does look like it's not quite horizontal, and combined with the fact that the Patrol is higher than a normal car, and it looks as though the driveway slopes away a little too, and these are all exagerating the angle. And you're right, they are a PITA to remove when on this angle.

I actually have two tongues I use on my Pajero. Each one with the towball fixed opposite to the other, so I can quickly interchange them depending on the trailer. Beats having to undo the towball each time.

But part of monkey's problem is how far back the coupling was mounted in the first place. So trimming the drawbar back will help, as will turning the towbar tongue over.

monkeyrelish
1st Aug 2010, 07:04 PM
Righto, time for an update..

Thanks for all the replies.. To answer some of your questions no there is no optical illusion the ground is sloping (driveway). The tongue on the Nissan is at an angle for what ever reason I don't know.

I decided to fix the stuff up with the trailer rather than muck around with flipping the tongue etc..

So anyway I finally got some time in the shed, and set about trimming back the draw bar to where the safety chain starts. Then filed the burrs and a few coats of cold gal and all done.. 10min job too easy:2tsup: I love those 1mm cut off disks:U

http://i921.photobucket.com/albums/ad59/monkey_relish/Boat/Alldone.jpg

In the pick you can see that on the other side its a little wonky, nothing to do with my ability to hold the cut off wheel straight. This is how far the end was mashed back, so it looks a little untidy there but it works..

Went out in the boat today and had no dramas at all.. big relief..

Thanks again for all the advice.

Cheers

soundman
2nd Aug 2010, 11:42 PM
a couple of thaughts.

you might want to put a run of weld on the inside of that safety chain link or even better start agian.

Um that shackel you are using will have bucklies of holding......un rated shackles are realy weak....best to replace it with a rated shackle.

and
with the safety chain the way it is rigged if the trailer jumped off the ball the drawbar would strike the ground.

Nothing unusual..pretty well par for the course

But a while ago a mate had a coupling failure on a fully loaded mowing trailer.......he was very lucky it came out so well.
the drawbar struck the ground and the safety chain ground thru on the road

It gave us all a wake up around here.

I got the job of replacing the hitch and the safety chain......we went with a double safety chain arrangement that made it easier to cross the chains either over the tongue or under the coupleing, and for the chains to be the right length.

Note that hayman reece recomend taking the chains over the tongue in front of the ball.

cheers

Yonnee
3rd Aug 2010, 11:00 PM
Well I don't know about anyone else, but I can't see whether there's anything stamped on the shackle to determine whether it's a "rated" shackle or not. Never mind the fact that there is no requirement for a "rated" shackle on any trailer, only the chain itself.

Nothing wrong with the chain attachment, ADR62 requires a weld around 50% of the link's circumference, which it looks like it is.

soundman
4th Aug 2010, 12:00 AM
clearly and plainly it is not a rated shackle, the proportions are wrong and rated shackle almost always have forged ( not stamped) print both sides.

And the shackle is small in relation to the chain, shackles are considerably weaker than the same weight chain, to achieve the same strength as the chain in the same material, the shackle needs to be considerably bigger than said chain.

The point being that hardware shackles are incredibly weak and most variable and unreliable.

At least a rated shackle you know what you are getting, any rated shackle will have a failure strain ( that is measured by any distortion not necessarily breakage) at least 4 times ( some brands up to 8 times) rated rated load and it will be alloy and therefore considerably stronger than even the best mild steel shackle of a similar size.

while it is not a legal requirement, using rated shackles is a wise thing to do...for the want of 5 or 6 bucks extra, why wouldn't you.

It is incredibly common to see very small cheap nasty shackles used on safety chains, put under the shock loading of a coupling failure they will snap like twigs.

as far as the safety chain is concerned....the weld at the front of that link is now not worth a cracker, some of the fillet has been cut away and the renainder is unsupported and in a failure situation, that front portion of weld would easily tear away.

Remember the regulations are an absolute minimum.

When you have seen a even 1 failed safety chain, those minimum standards seem inadequate.

I have seen one situation where I know first hand the exact situation, that was quite low speed....I have seen several trailers with much worse damage to the safety chain.

When you see a mate shaking like a leaf by the side of the road, because he has had a fully loaded trailer get away in a major intersection, you get a new respect for safety chains and what they are there for.

cheers

buildspacetrain
4th Aug 2010, 06:25 PM
My trailer build is getting more expensive every time i log onto this site!!!
Rated shackles I never knew about.:doh: Sounds like a good idea.:2tsup:
Anybody lend me some more money?

soundman
5th Aug 2010, 01:15 PM
I have been surpriced how cheap rated shackles are these days..as long as you go to the right place....for me that is my local bolt shop.

hell the big 3.2 tonne rated shackles I have for yanking the 4wd out with are only about $20.

1/2 tonne or 1 tonne shackles should only be $5-6 bucks each $10 if you are buying badly.

And yes there is wide spread ignorance of rated shackles and the poor quality of hardware shackles

cheers