[royce]

[Mike]

good looking bar
are the rear quarters cut to fit it?
does it just bolt to the 4 outside towbar mount holes?

[royce]

yes to rear quarters
yes 4 12mm bolts and 4 6mm up the sides, you can jsut make em out in the pic

[Mike]

its bolted to the quarter panels?

[royce]

nope, why would I want to do that it would tear the body apart when the bodymounts flex

[Bruce]

Shit that's an old picture Royce

[Bruce]

Look at that tyre wear from ya CIG rear

[Mike]

royce wrote:

nope, why would I want to do that it would tear the body apart when the bodymounts flex

thats what i was thinking
would just the four bolts be strong enough?

[royce]

a 12mm gr8.8 bolt has a minimum breaking strength of 2.7 ton, so spread across the 4 there is 10 ton of load before the bar can tear off fully, I would think the chassis would give way 1st and if you are able to generate that much load in a sierra you should be drag racing it and if you are stuck enough to generate it you need to rethink your recovery

the yellow recovery plates are 10mm thick and also the bar mounts so no load is placed on the bar when using the points

[Zook_Fan]

yeah that bar wont give way. we tested it with a 4.2L diesel patrol pulling it while the hand brake was on and it didnt budge.

[Mike]

are the mounts in the chassis strong enough or will i tear the bolts out?

[royce]

I think the chassis would give way 1st, but is strong enough for sensible recovery, that is dont pull anything other than a stuck sierra out and make the recovery as easy as possible and trust whoever is pulling you out isnt a cowboy that thinks he needs to be doing 50 in his GU before the strap gets tight

[Mike]

is there a simple way to attach a bumper that you could pull out say a hilux with?

[Zook_Fan]

im pretty sure mine will be able to recover other vehicles as that chassis is almost 1/2 inch steel, so it isnt going to rip out easily. and the bolts wont go as they are high tensile along with the nuts. Made them up on the lathe ourselves

[Mike]

your chassis is made of 1/2 inch steel?

[Zook_Fan]

I think the pervious owner did some serious towing (caravan or something) and yeah this part of the chassis is atleast 1/2 steel on top of that the bolts go through the 1/4 inch mounting steel and underneath is the towbar mounts. It isn't going anywhere fast

[Mike]

serious towing with a sierra?
are you talking about the flat plates with 2 holes on each side of the chassis or do you mean the actual chassis rails?

[Zook_Fan]

probably the flat plates but i was pretty sure it was the chassis not sure ill check it out

[Mike]

i'm pretty sure the chassis rails from the facotry are made of 2.5mm steel

[Zook_Fan]

then i would go out on a limb and say that it is the plates welded there

[lump_a_charcoal]

Anyone got pics of a rear bar, used for recovery, with a long range tank too?

[brendan]

royce wrote:

a 12mm gr8.8 bolt has a minimum breaking strength of 2.7 ton

how did you work that out?

[royce]

I didn't, somebody with a whole lot more smarts than me told me

8.8 in a bolt rating is the tensile strength in MPA, that with the cross sectional area of the thinnest part of the bolt (normally in the thread) is enough to figure it out

[brendan]

do you know the calculation for it?