Thread: Shackle bolts and bushes for repaired trailers

We have a discount car place where things are fairly cheap usualy I got new high tensile bolts for $10 a pair so it is similar to your price. I couldn't be bothered going to the engineers supplies who are generaly dearer these days anyway. Rubber or Nylon you will get at least 5 years out of the bushes either way I would think.
Auto one or someone like that should have things at a reasonable price.

Thanks Claw Hamma for your response,
I have been to town this morning at have been dicked around wherever I went.

In your town you probably get good service .In my town many outlets employ younger people,Auto Bahn,Supercheap, Repco who apprently have little experience or interest in the job they are doing.

The majority of these lost souls would appear to suffer from the dreaded stunned mullet syndrome and are frustrating in the least, to deal with.

The trailer sparts "specialist in our neck of the woods, Tyre power wants $5 each for what appears to 8*8 Grd bolts, I grant you that they have a spline area under the head ,but hey! they are not worth the $5 to me.

We have 2 trailers - ie 12 bolts, so 60 bills for shackle bolts alone ,sorry don't think so, as theres still U bolts and shackle bushes to purchase.

Repco have a good selection of automotive shackle bushes in both rubber and urethane but nothing in trailer parts despite having advertised this fact on their website. Kudos though to the efficient young lady who tried very hard to assist me,but to no avail.

I found some M12 x75 GRd. 8*8 bolts at $1.32 each, c/w spring, flat washers and nyloc nuts and got trade on them to boot.

For the bushes, I found I can buy urethane equivalent rod of the correct OD from the local plastics guy and drill them to the shackle bolt diameter.

The U bolts we will fab using staright 8*8 bolts with fishplates either end using an adaptor for the circular axle.

Problem solved at an affordable price.

I have been taking pics and will post them as we make more progress on the project.

cheers'

Grahame

I would challange anyone to find a mass produced 6x4 on the Australian market that runs anything other than mild steel shackle bolts and 'U'bolts.

Melbourne Trailers sell the Nylon Bushes for aroud $2.50ea. and 'U'bolts with nuts & washers around $15.00 a trailer set. (from my 8 year old price list from when I worked there, plus a bit for price increases over the years.)

39mm round is the common size for 6x4 trailer axles, Holden bearings, 750Kg rated.

You're right about the hiring of kids as sales staff in the automotive game. Having worked there too, the automotive retail industry doesn't pay enough to keep the experienced guys. And the likes of eBay and on-line stores don't help as profit margins are fairly low as it is, so paying $50-60K to keep the good staff is out of the question.

Hi ,those mild steel which are zinc plate are brittle if not heat treated right.
M12 at 1.32 is a good price in my book.
39 mm kits at Marshall trailers are $23.00 + bushes.
they will post.

you could make them up at school.

staff at some shops ??????????


Tony

The local plastics supplier wants $50/metre for 22mm urethane.

Thats 10 per length at $5 each more than double the price of buying them each locally at $2 per unit. Add to this urethane is a bitch to machine .

To get the 12mm bore I require, you need to drill with a 14mm spade bit as the brrstard shrinks - bigtime. Got this right from the horses mouth today.

I can get the bushes in Brisbane cheaper than that again and probably will end up getting 50 at a time as we will be doing half a dozen new trailers a year a year and upgrading some of the local registered rolling wrecks to a safe and roadworthy condition. same deal with the hardware.

Evening all

As I said I would, have posted some pics of the trailer we are currently refurbing.

You might note the 70 x 70 x 5 A / section looks out of place but it is what we have and there not a lot of spare cash around until Anna Bligh gets paid for our railways she is flogging off.

The first piccy is the box frame stripped of the 50 x 25 x 1.6mm RHS gal frame that turned to rust dust in places after a few blows with a hammer.

Chassis and a frame drawbar were made from this Zhit and thechosen materials and construction were a good argument why people who haven't got a clue, should not be allowed to place people lives at risk.
It worries me that trailer manufacturers are making frames from 100 x 50 x 1.6.

The second pic is the A/s attached and fitted up to the box side.

Pic 3 note the coped and bevelled joint.

As the schools name will be on the VIN plate only selected cherubs who have passed my weld test will be permitted to weld on the chassis and that is only with MMAW.

Continued when I get a chance to take some more pics.

Grahame

Originally Posted by Grahame Collins

Pic 3 note the coped and bevelled joint.

Hi Grahame,
What is the benefit of such a joint, over a normal butt joint?

Originally Posted by Vernonv

Hi Grahame,
What is the benefit of such a joint, over a normal butt joint?

A coped joint is easier to layout and easier to maintain square in the tack up /alignment sequence.

The reason for the bevel is that,in this case I don't want a welding bead inside - its where the floor sits- and you can,t grind inside corners of a corner joint. To gain best advantage of the weld deposited the joint is bevelled so most of the weld is laying below external surface flush line.

While down at the trailer place buying u bolts , I asked about the sealing. It is indeed the product, Sikaflex, keeping the water out of the joints.

If you come in late at this part, I previously saw sealant used in brand new trailers as a fillet in all of the the corner joints.

I had a rush of excrement to the brain and thought, if this stuff is so good why not stick the floor down with full beads of it in lieu of tack welds .

Would this then prevent water entering under the floor and thus prevent premature rust out of said floor - the demise of most trailers.

Similar adhesive is used in car panels these days,so why not? My feeling is if the floor has not metallic contact with the rest of the metal components, rusting will be vastly reduced.
I would value it if you have current pertinent information on this .Yes I have googled but not much is coming up.

Grahame

Thanks for that Grahame.

As far as the sealant goes, I have been using Fuller's Fulaprene 303 as a seam sealer on auto panels and have been very pleased with the results. It is water and air tight, can be painted and sticks like the proverbial to a blanket.

Graham,i once worked at newnhams body builders in melbourne and we used sikaflex (adhesive)to stick bus and coach sub floor bin door skins to rhs frames,there was not a single rivet holding those skins on and those coaches were doing around australia trips and red centre tours their whole working life,i notice that denning coaches are rivet free as well as are volgren etc so the adhesive at least works well.As far as a sealent goes i can vouch only for one big job and it is second to none,hope this helps,danny.

Thank you Daniel,

I'll be a keen observer of every coach I pull up to, at the lights.

I can't see why it would not work on the trailer, no info as no one has tried it yet.

Thanks
Grahame

I don't intend to offend anyone, but there are some real problems here.
Is it not the point to teach these students the correct way?
There are some glaring failures in the project thus far.
1/ In the photos posted I note that none of the angle iron has been wire brushed or cleaned in any way. This contravenes standard workshop procedure on several levels. A: The material will be far easier to clean for painting now than when assembled. B: The practice of welding rusty material is not a good one purely on strength grounds. C: Far better quality oxy acetylene cut will be achieved with clean material. D: It is far more pleasant working with clean material.
2/ I notice that the paint has not been cleaned off the sides before welding. This presents two problems at least. A: Toxic fumes produced during welding, particularly considering that this is an old trailer and may well have been painted with goodness knows what. B: Welding over paint is not a wise practise and it makes a heck of a mess when it catches fire and has to be cleaned up later anyway.
3/ I take it that you are not going to weld the inside corners of your angle iron chassis. Why ever not? All that would be required is to snipe the corners of the floor to allow them to clear, (you will not be going size for size anyway, remember angle iron has internally radiused corners)
4/ While all manner of adapters could be utilised to allow M12 8.8 bolts to be used, (these are only the equivalent of an SAE Gr5 bolt anyway), no workshop would ever do this as time is money and the correct product is available ie a U bolt.
5/ The use of M12 bolts in the shackles presents the problem of an immediate oversize hole, the shackles are designed for 1/2" bolts.
6/ The bushes used in trailer springs are not generally urethane but are nylon, which machines quite nicely, although why you would bother I do not know when bushes are so cheap.
7/ This is a trailer that will be 750kg ATM, I have never seen a mild steel shackle bolt fail yet, even on tandem trailers overloaded to extreme levels. Do the calculations for the shear load of a 1/2" mild steel bolt and tell me it's not adequate.
If any of my apprentices, other than a very green first year approached this project, in this way, then I would be sitting down with them and having a long talk about what we were actually trying to achieve and basic workshop practice.
Some areas appear to have had little thought, while others have been over thought. I realise that schools are on a tight budget, but good trade skills cost nothing and will save much.
I am not totally negative, in fact I think that this is a good project for a school. The execution thereof does seem rather amateurish though.

Hi Karl
Hey! Im not offended but there area number things that you should be aware off.
Glaring failures, perhaps only in some of the assumptions you have made about our situation as there is a lot you are unaware off.
1.
A.
The joints were dressed ( ground ) before tacking. The angle sections were hand wire brushed before assembly and being permanently located on the concrete apron of the building have rusted since the assembly. The welding can't take place on the same day as the tacking /assembly. There has been a number of weeks elapsed between the tack up and when photo was taken. Your work shop environment will be quiet diferent from that of ours in humid tropical North Queensland which will rust a prepped surface over night. What you see was the results of weeks of exposure after heavy rainand humidity

Timelines in our school workshop are quite different to what happens in a real workshop as in the trailer may have got left because the kids I want to work on it are away or working on another job I could,t risk putting some of the lesser skilled kids on.


B,C& D , I agree in principal with your comments but in not in practice – difficult in our set of circumstances. Our shop is rust city with the prevailing sea breeze blowing effluent from the sugar mill smokestack and the coal dust from the coal loading railway wagon marshalling area, all falling over and in our shop.

Oxy cutting? Some joints were very well cut . I have a couple of students that can split the witness pops on a circlecut. Other kids unfortunately can,t be bothered to select and fit the correct tip for the met l thickness and adjust a flame.

2 .The student who welded over the that paint was in fact instructed to scuff the paint off with a grinder, but he is one that occasionally does not follow instruction. He is a get er done type kid from a farm background-good workethic but PITA safety wise. Yes it was 2 pack paint by the smell. The yound feller paid the price and was ill overnight but luckily has suffered no lasting effects .

On that particular day I was intent on keeping a very close eye on a very difficult student seemingly intent on killing himself with a lathe chuck key that he kept leaving in the lathe chuck.

One of my other students has connections to the sand blasting industry and reckons he can arrange a light plast before we weld it up.

3..The inside corner will have a flat bar 50 x 3 intermittently tacked in and sealed with Sikoflex or equal product as I have seen in manufacturer trailers up this way. This leaves no floor joints seams for ingress of water.

The fixed end will have some PVC drain tubes at floor level & sealed again with Sikaflex.Yes Its an experiment On the trailer that will be used to cart goatsand chickens to agricultural shows 3or 4 times a year. I shall monitor the trailer out of interst and if theres a problem,will fix it.

4/ I have since ended up finding cheap shackle bushes from a trailer parts suppliers and appropriate imperial bolts for them.

5/ See above ,but yes theres was a learning curve, about dimension types of trailer parts,Ok I did not realise these parts only come in Imperial-I made an assumption everything these days is metric and was wrong!

6/ Not going to bother machining but will be buying bushes in bulk. I have had a big learning curve after talking to trailer parts supplier.


7.After undoing some of the MS bolts off these trailers they snapped like carrots. That was good enough reason for me. I don’t intend to get into any arguments about shear strength- Grd 8 structural it is then!


Karl You have apprentices ,over whom you will have a some measure of control.
I have 12 out of 20 students who will never be apprentices because of their own slack attitude to what ever they do and have chosen this course as a means to avoid working and other subjects. Some of them can’t turn up for work regularly with boots safety glasses or a pen and notebook and most did not pass English maths and manual Arts subjects since Grd 8 or.9.

They were placed with meagainst the will of my HOD and myself because in the words of the Deputy Principal we have no where else to put them.And yet we have had acheiving students who were denied places in our course to make the academic side look good.

You, have this luxury of some form of leverage over your apprentices, meaning that it is possible to improve orremove them if they don’t perform. Unless my students do something very very serious all we able to do is make it very difficult for those kids (within the rules) that they leave school or change subjects. I have done this for 12 students over 2 classes over the 2 years Grades 11 &12 .

This has worked for a number of them. I am caught between the devil and the deep blue sea in being saddled with a big group non achievers and providing the classes with interesting jobs to keep them occupied and therefore out of trouble., which generally occurs in the form of vandalism or ignorance /accidental damage to the shop or equipment. In short I am really a highly paid child minder for some of them. Budget is a major factor in all that we do. The shop machines have to be up scratch and that consumes a 1/3 rd of the $10.000 we are allocated. the place is run on a shoe string budget and there is never enough of anything.


Rest assured the trailer will go out safe and pass inspection. I hold a PV supervisor & welding inspectors qualification,17 years as a Tafe metalfab instructor ,before even coming to a high school so I think I can still manage to get the trailer to a standard that it won’t kill anyone.

Out of two classes originally of 32 students, I would expect perhaps half a dozen of these kids to make decent apprentices. The rest believe they can mark time for the last 2 years in school ,acheive nothing and then gain jobs in the coal industry. Good luck to them!

As far as manufactured trailers go some of the brand new ones are not too flash. How many are welded transversely across the drawbar ( stress cracking) some what more serious than welding over rusty plate. Or the pieces of junk fabbed using 1.6mm wall thickness Duragal for a drawbar.

Chippies buy these bloody things because they are cheap, then load them up to the gunnels with half a ton of tools on them and drag them to and from building sites daily.

I have knocked back a few that wanted repairs to such drawbars when I wanted to replace the whole drawbar with something substantial.

Thats my 2 bobs worth then.

Grahame