Standard Toyota L/C hooks straighten @ 4.6 tonnes, About the same as a Bushranger hook.
Hilux hooks however, by design, push the rope further away from the mounting plane of the bolts, causing the rear bolt to stretch and snap , then shearing the front bolt, 8.8 bolts failing @ 4.5 tonnes.
Bighorn hooks do the same thing, std 10mm bolts failing arround 5 tonnes,
Drilled out to 12 mm, 8.8 bolts still fail but 10.9s hold till the hook breaks @ 8.18 tonnes.
All of these tests were straight pulls on a test rig not snatchs
J Top
Whats the chances of organising a Chch Beginners day?
DaveM wrote:I thought that rated hooks were used as they were designed to bend open when overloaded, rather than having a higher rating than the straps?
Thought that was why a lot of clubs won't allow pintle hooks as recovery points.
Either way, you can buy these for the rear of a safari:
http://www.trademe.co.nz/Trade-Me-Motor ... 594552.htm
Muzzaduck does good work - well thought out and engineered
JTop wrote:Standard Toyota L/C hooks straighten @ 4.6 tonnes, About the same as a Bushranger hook.
Hilux hooks however, by design, push the rope further away from the mounting plane of the bolts, causing the rear bolt to stretch and snap , then shearing the front bolt, 8.8 bolts failing @ 4.5 tonnes.
Bighorn hooks do the same thing, std 10mm bolts failing arround 5 tonnes,
Drilled out to 12 mm, 8.8 bolts still fail but 10.9s hold till the hook breaks @ 8.18 tonnes.
All of these tests were straight pulls on a test rig not snatchs
J Top
Thats useful tech... might have to combine all these figures into a tech doc in the library section...
Does anyone have access to the video clip where they tested recovery forces and found that even violent snatches were only peaking at around 3.5 tonnes? Its all from a very hazy memory of seeing it somewhere...
Anyway, Wednesday night at the shed I'll be fitting a tow hook to a Surf... anyone else want to come down... make it a pizza, beer and towhook evening? We can do a pre-inspection of your setup... make some recommendations, maybe fit a couple of hooks...
Steve
http://www.trademe.co.nz/Trade-Me-Motors/Car-parts-accessories/Toyota/Other/auction-67594552.htm
Is something like this classed at rated? Not so much the hook part, but the plate section its welded too.
Reason I ask is because I need something like this for the back, but Im sure not going to pay that price for one. Id make it myself.
In making one, as thats all I assume that person is doing. Do you need to get it rated? Or what goes on there? AM I just allowed to make one myself, or do I need to get an engineer to weld it and cert it?
Is something like this classed at rated? Not so much the hook part, but the plate section its welded too.
Reason I ask is because I need something like this for the back, but Im sure not going to pay that price for one. Id make it myself.
In making one, as thats all I assume that person is doing. Do you need to get it rated? Or what goes on there? AM I just allowed to make one myself, or do I need to get an engineer to weld it and cert it?
Hook looks fine I would queston the suitabilty of what is connecting it to the chassis though. I saw a very similar design last year, on a well equipped rugger on our club trip to big barn bay down in sth westland. It tore, yes tore off at the mounting bolts through the plate connecting it to the chassis. This equated to a missile connected to a rope flying through the air, no damage luckily, except to the tree it hit. Go and see Steve he will set ya right. 
Al
Al
rain, hail, sleet or snow, we go!
4x M10 8.8 bolts failed at 11 tonne on a straight pull
However on a 70 degree angle they failed at 6.16 tonnes
Patrols only have 10mm mounting bolts, most vehicles have 12mm at that point.
This did not test the strength of the factory captive nuts.
4 x M12 8.8 bolts stalled the test rig @ 20 tonnes on a straight pull and failed just under 10 tonne on a 70 degree angle
J Top
However on a 70 degree angle they failed at 6.16 tonnes
Patrols only have 10mm mounting bolts, most vehicles have 12mm at that point.
This did not test the strength of the factory captive nuts.
4 x M12 8.8 bolts stalled the test rig @ 20 tonnes on a straight pull and failed just under 10 tonne on a 70 degree angle
J Top
Have seen this area on a Safari deform from a hard recovery, which is why I just had my hook mounted on the rear bar:
http://www.equip4.co.nz/rear%20bumper.htm
http://www.equip4.co.nz/rear%20bumper.htm
Yeah, I'm not a big fan of the 4-bolt recovery points on the rear of a truck, and have always been stunned that my little MU has M12 bolts and a big-arse ugly mutha GQ poo-troll has M10's... crazy!
I prefer to mount the hooks inline with the chassis rails, and for safety reasons, the passenger side rail in case something comes back at ya (that way it hits the passenger rather than you
Eh Rik, my trusty co-pilot )
However, if you've got a good solid rear crossmember, with good condition M12 captive nuts then the bracket is (well, should be) safe to use - or you can drill through, sleeve and plate the crossmember to add strength and allow for new M12's.
The only difference between that rear bracket from TradeMe and the one I make is that I use folded 6mm plate with gussets on either end double-welded... theres not a lot of room between the bolts for weld fillets.
Sometimes its a matter of comprimise, maybe centre mounting the hook when you want it on the rail, or running the hook upside down when you'd rather have it the other way up... which is ok, as long as the finished product is effective, safe and strong.
Anyway, 5:30/6pm at the shed seems like a good time... all welcome... bring pizza, bring a couple of beers (ie, 1 or 2... no drink driving), bring hooks, bring your truck... if it rains, it will have to be postponed as theres not a lot of inside room.
Steve
I prefer to mount the hooks inline with the chassis rails, and for safety reasons, the passenger side rail in case something comes back at ya (that way it hits the passenger rather than you
Eh Rik, my trusty co-pilot )
However, if you've got a good solid rear crossmember, with good condition M12 captive nuts then the bracket is (well, should be) safe to use - or you can drill through, sleeve and plate the crossmember to add strength and allow for new M12's.
The only difference between that rear bracket from TradeMe and the one I make is that I use folded 6mm plate with gussets on either end double-welded... theres not a lot of room between the bolts for weld fillets.
Sometimes its a matter of comprimise, maybe centre mounting the hook when you want it on the rail, or running the hook upside down when you'd rather have it the other way up... which is ok, as long as the finished product is effective, safe and strong.
Anyway, 5:30/6pm at the shed seems like a good time... all welcome... bring pizza, bring a couple of beers (ie, 1 or 2... no drink driving), bring hooks, bring your truck... if it rains, it will have to be postponed as theres not a lot of inside room.
Steve
SupraLux wrote:Anyway, 5:30/6pm at the shed seems like a good time... all welcome... bring pizza, bring a couple of beers (ie, 1 or 2... no drink driving), bring hooks, bring your truck... if it rains, it will have to be postponed as theres not a lot of inside room.
Whens this? could SAS the Lude...
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Who knew Prados could fly?
Who knew Prados could fly?
Was a good excuse to talk crap though.