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Mounting a winch

Posted: Sun Mar 22, 2009 9:39 pm
by TUFF60
Can i mount a Warn 9000LB winch with the mounting face, face down mounted on the horizontal with the bolts coming up from underneath or does it have to be mounted the normal way with the mounting face vertical.

Posted: Sun Mar 22, 2009 9:43 pm
by daveo
my XD9000 is mounted feet down in a TJM bar.

Posted: Sun Mar 22, 2009 9:59 pm
by PJ.zook
It can be mounted horizontal, but keep in mind that bolts are much stronger under tension than they are shear.

Posted: Sun Mar 22, 2009 10:00 pm
by TUFF60
Thanks mate.

Posted: Mon Mar 23, 2009 10:36 am
by bogged
daveo wrote:my XD9000 is mounted feet down in a TJM bar.
x2

Posted: Mon Mar 23, 2009 3:52 pm
by marin
PJ.zook wrote:It can be mounted horizontal, but keep in mind that bolts are much stronger under tension than they are shear.
I agree with that, the bolts are designed AND RATED to pulled lengthways (tension), not across them (shear). Check the mountings and the bolts and see if they seem appropriate for mounting that way.

marin

Posted: Mon Mar 23, 2009 3:54 pm
by marin
bogged wrote:
daveo wrote:my XD9000 is mounted feet down in a TJM bar.
x2
You can have everybody on the internet saying they have theirs mounted feet down, doesn't make it right or safe (not saying it's unsafe though)

marin

Posted: Mon Mar 23, 2009 4:19 pm
by LOCKEE
Funny Warn recommend that they can be mounted either way. Most US mounts are feet down.

Posted: Mon Mar 23, 2009 4:28 pm
by mike_nofx
I wouldn't worry about the bolts, I'd be more worried about the thin alloy(?) section its bolted to (winch feet)!

Posted: Mon Mar 23, 2009 4:57 pm
by v840
http://www.rockcrawler.com/techreports/ ... /index.asp


Using the formula from the above article, and substituting numbers in to represent a 10mm hi-tensile bolt (10mm = 0.394") ,which is probably the minimum bolt size I would use to mount a winch with we can see:

Using a .394-inch diameter (10mm) grade 8 fastener gives you the following shear capability:

A = Cross-sectional area of the fastener size (since bolt bodies/shanks have circular cross-sections, use area of a circle) = Pi x r2 where R (radius) = .394/2 = .197, therefore A = Pi x (.197)2 = .122(3 dec. pl) square inches (in2)

Capability in shear = 91,000 lbs / in2 x .122 in2 = 11102 lbs or 5055kgs (rounded up to nearest kg)

So 1x10mm Hi tensile Grade 8 bolt has a higher shear strength than the winch should theoretically be able to pull. Mounting a 9000lb winch using 4 of these should be fine in other words.



Interestingly, if you go up a size to a 12mm bolt, the shear strength becomes 15925lbs which is roughly 7223kg that's over a two tonne difference in shear strength in 2mm!




I'm aware that there are other factors in winch loads but it should not realistically make a difference if it is mounted feet down or otherwise. Just use sturdy grade 8 hi tensile bolts and you should be sweet. Of course what you mount it to makes a big difference as well. ;)

Posted: Mon Mar 23, 2009 9:08 pm
by TUFF60
I had already upgraded to 12 mm bolts so, see how we go.