Outer Limits 4x4 Board

G'day. I recently mounted a factory pto winch to my gq and then sourced down some genuine shear pins from nissan, i was told to do this so no harm is done to the winch. So i bought 3 of them from nissan. I have now broken 2 of them and the problem is they broke pretty much as soon as the winch cable took the weight of the vehicle! Both times where on a hill climb and as soon as the slack was just taken up that was it! I know some guys on this forum run these pto's for comps in NZ. Was hoping you might be able to help, or has anyone else had this problem? Is it possible nissan has different grades of pins? There is no way they should of broken.

I am not in NZ and dont use mine in comps...it is an MQ too. but....

I would say run a grade 5 bolt, nothing harder. softer it will break pretty easy.

We've replaced the shear-pin with a piece of stainless rod machined down to suit. Haven't actually broken one, but they get a bit twisted after a few comps, so it gets a fresh one regularly.

Some people use a high-tensile bolt instead.

GQ TROL wrote:We've replaced the shear-pin with a piece of stainless rod machined down to suit. Haven't actually broken one, but they get a bit twisted after a few comps, so it gets a fresh one regularly.

Some people use a high-tensile bolt instead.

Will a engineering place just machine this up if asked?

dwaynes wrote:

GQ TROL wrote:We've replaced the shear-pin with a piece of stainless rod machined down to suit. Haven't actually broken one, but they get a bit twisted after a few comps, so it gets a fresh one regularly.

Some people use a high-tensile bolt instead.

Will a engineering place just machine this up if asked?

Cant see why not. Drill a hole through one end for your split pin and you're away.

GQ TROL wrote:We've replaced the shear-pin with a piece of stainless rod machined down to suit. Haven't actually broken one, but they get a bit twisted after a few comps, so it gets a fresh one regularly.

Some people use a high-tensile bolt instead.

and have you ever placed to much strain on the winch by doing this? Sounds like it might be the go...

I broke a couple on my old GQ, but not that easy!
Are you sure there isn't any binding between the winch and shaft to put extra strain on the pin when winching?

ROGQ wrote:

GQ TROL wrote:We've replaced the shear-pin with a piece of stainless rod machined down to suit. Haven't actually broken one, but they get a bit twisted after a few comps, so it gets a fresh one regularly.

Some people use a high-tensile bolt instead.

and have you ever placed to much strain on the winch by doing this? Sounds like it might be the go...

It typically increases the wear on the bronze worm wheel, to the point where you have to turn the wheel around after 2 comps so it can wear on the other face. So a worm-wheel / worm drive set will do 4 comps before being retired.....these are some rediculous pulls though, enough to snap 11mm dia Amsteel Blue like it is cotton.

On one occasion we sheared the main centre-shaft through the centre of the winch...its about 30mm dia. The stainless "shear pin" had a bit of a bend to it.

You've got to decide if you want to get home in one piece and accept some premature wear, or do no damage to the winch and be stuck out in the scrub overnight while you keep replacing shear pins. I've slept in my truck before, it aint much fun.

I would look to see if it is binding up as Kiwi suggested.

funny you should metion binding.. cauz the two times i've had to replace the pins. I have literaly had to lever the shaft forwards (towards the front of the vehicle) with a steel bar as the shaft hole and the pin hole did not line up. I'm probaly talking about 5mm. And i was levering on it hard, alota effort. Is this normal or should they just pop out. When i welded the supports for the winch in place there was no strain at all on the winch obviously and it was just sitting in place so i don't see how it could have any pressue on the shafts unless something has bent or twisted...

ROGQ wrote:funny you should metion binding.. cauz the two times i've had to replace the pins. I have literaly had to lever the shaft forwards (towards the front of the vehicle) with a steel bar as the shaft hole and the pin hole did not line up. I'm probaly talking about 5mm. And i was levering on it hard, alota effort. Is this normal or should they just pop out. When i welded the supports for the winch in place there was no strain at all on the winch obviously and it was just sitting in place so i don't see how it could have any pressue on the shafts unless something has bent or twisted...

Something doesn't sound right then. The splined slip-joint in the hanger-bearing should be such that you can move it up to the input shaft on the winch by hand and with little effort. Most of the ones I get are rusted / ceased at this point, which makes things difficult. Don't get heat near the bearing to loosen the joint, as you'll bugger it. Soak it in diesel or penetrating oil and give it some love with a BF hammer.

I just had a look under then. I think what is resticting the movement is that where the uni joint is where it slides onto the shaft of the winch (where there shear pin goes) I remember when i first was installing the winch that was tight as a nuns nasty. I had to bash the phuck out of it with a hammer to get it on. I will try the diesel on the splined part though but i would say thats where my problems with the breakages would lie.

ROGQ wrote:I just had a look under then. I think what is resticting the movement is that where the uni joint is where it slides onto the shaft of the winch (where there shear pin goes) I remember when i first was installing the winch that was tight as a nuns nasty. I had to bash the phuck out of it with a hammer to get it on. I will try the diesel on the splined part though but i would say thats where my problems with the breakages would lie.

Give it a go. It doesn't sound like that should be enough to break the shear-pins, but you've got start looking somewhere.

Thanks for all ya help.