DaveInDenver
Middle Income Semi-Redneck
Is it like a winch subframe that mounts in the bumper? Sounds cool.
Winch Mount Bolt Strength
- Thread starter Retired Tanker
- Start date
Hillbilly Heaven
Explorer
Yes mine is a subplate that mounts to the frame. When I installed it many years ago you mount the plate first and then the outer bumper ends mount to the subplate with diagonal bracing that also attaches at the frame/subplate mounting points.
Hillbilly Heaven
Explorer
I misspoke it is not an ARB but a Warn Classic bumper.
Mickey Bitsko
Adventurer
Not mentioned is the vehicle your winch is mounted.
It appears you'll be pulling a helluva lot of weight.
If you were to use an appropriate size snatch block you'd alleviate some concerned angst.
Mickey
It appears you'll be pulling a helluva lot of weight.
If you were to use an appropriate size snatch block you'd alleviate some concerned angst.
Mickey
Retired Tanker
Explorer
I’ve learned to love getting a mechanical advantage whenever possible. Would rather reduce risk than be in a hurry.
(Edit) Sorry, I forgot that you can’t see the vehicle in Tapatalk like you can on Expo. It’s a full size Sequoia. Just shy of 6,000 pounds. I spent 21 years as a tanker recovering 50-70 ton tanks from some pretty ridiculous situations; steep hills, buried to the turret ring in mud, rollovers, high centered, you name it.
So, yeah. Unless it’s a very simple pull I’ll always try to run at least 2 live lines.
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arctic04trd
Member
Retired Tanker
Explorer
So, those were the bolts that mounted the winch to its plate and it was a “feet-forward” mount?
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Sent from my iPhone using Tapatalk
DaveInDenver
Middle Income Semi-Redneck
Unless the front of your bumper has bent from the forces (which isn't impossible, but I would say unlikely), I'd guess it would be mounted like mine.
The overall view, two bolts through the fairlead cage, two upper ones directly through the bumper to the winch housing.
Those lower ones are extremely well supported, you'd have to run directly into an unforgiving concrete pole to distort them.
The upper ones have a decent amount of steel behind them but the holes are oversized and when you torque the bolts down with a thin washer it will dimple into the slot. I put grade 8 extra thick SAE washers under mine to support the fastener. For a 5/16" bolt those are 3/32" thick.
https://www.boltsandnuts.com/shop/5-16-sae-grade-8-extra-thick-flat-washers-zinc-yellow-39779
But even if you don't do this and let the washers distort they shouldn't be under any stress since the winch feet are being pulled into the bumper.
The overall view, two bolts through the fairlead cage, two upper ones directly through the bumper to the winch housing.
Those lower ones are extremely well supported, you'd have to run directly into an unforgiving concrete pole to distort them.
The upper ones have a decent amount of steel behind them but the holes are oversized and when you torque the bolts down with a thin washer it will dimple into the slot. I put grade 8 extra thick SAE washers under mine to support the fastener. For a 5/16" bolt those are 3/32" thick.
https://www.boltsandnuts.com/shop/5-16-sae-grade-8-extra-thick-flat-washers-zinc-yellow-39779
But even if you don't do this and let the washers distort they shouldn't be under any stress since the winch feet are being pulled into the bumper.
arctic04trd
Member
Yes, feet forward
So I upgraded everything to grade 8. It was grade 5, or 8.8 for metric.
This is how mine is mounted. I doubt the ARB bumper bent. But I guess its possible. It doesn't look wrinkled anywhere underneath or on the back side.
Hillbilly Heaven
Explorer
I agree with the above those slotted holes provided little support to that thin washer. A thicker and better grade of washer would be advised.
Are there no bolts from the bottom? My Warn winch bumper and M12000 winch has 4 mounting feet on the bottom and 4 front face mounts. With the one piece winch plate securing the bottom and front of the winch with 8 bolts and and the plate tied directly to the frame, I don't think mine is going anywhere.
Are there no bolts from the bottom? My Warn winch bumper and M12000 winch has 4 mounting feet on the bottom and 4 front face mounts. With the one piece winch plate securing the bottom and front of the winch with 8 bolts and and the plate tied directly to the frame, I don't think mine is going anywhere.
rickc
Adventurer
For what it's worth my new ARB bumper has 10.9 bolts on all the main frame-to-bumper points and 8.8 bolts on the lighter stress items like skid plate to bumper. The winch bolts are only 8.8 because the winch is turned feet forward into the bumper; pulling on the winch pulls the winch into the bumper.
Coachgeo
Explorer
don't assume manufactures are just cutting cost with lower grade bolts. there is differences in strengths from different forces. In some places a lower grade is better cause they bend and weaken.. but do not SNAP off without warning/need of a stress gauge to let you know it is about to happen. If you change bolt grade from what manufacturer suggest.... it is also possible you void warranty if something were to happen and god forbid someone is hurt.
DaveInDenver
Middle Income Semi-Redneck
This isn't right with one exception, grade 9 and metric grade 12.9. When you compare the yield and ultimate points of grade 5 and grade 8 or metric 8.8 and 10.9 you'll see the point where the higher grade yields, e.g. deforms, is higher than the ultimate, e.g. failure, point of the lower grade.
The only reason to use a grade 5 is cost and I can't imagine using a fastener as a fuse when mounting a bumper, winch or recovery point. There are of course shear bolts and pins that are expected to fail rather than destroying rotating machinery, but are there cases where a designer would expect a bolt to fail? I'd think you'd always design to be well under a fastener's strength and if that's not possible you would size up or use multiple fasteners. Replacing a 5 with an 8 (or 8.8 with a 10.9) would get you extra margin.
The exception about 9/12.9 is that there is a chance that they can experience hydrogen embrittlement if they are electroplated, so those are special application fasteners.
This page walks through examples: http://tinelok.com/grade-5-vs-grade-8-fasteners/
The only reason to use a grade 5 is cost and I can't imagine using a fastener as a fuse when mounting a bumper, winch or recovery point. There are of course shear bolts and pins that are expected to fail rather than destroying rotating machinery, but are there cases where a designer would expect a bolt to fail? I'd think you'd always design to be well under a fastener's strength and if that's not possible you would size up or use multiple fasteners. Replacing a 5 with an 8 (or 8.8 with a 10.9) would get you extra margin.
The exception about 9/12.9 is that there is a chance that they can experience hydrogen embrittlement if they are electroplated, so those are special application fasteners.
This page walks through examples: http://tinelok.com/grade-5-vs-grade-8-fasteners/
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arctic04trd
Member
I forgot to reply to this. I had the Warn fairlead that came with the winch. Its powdercoated steel. I have since gone to a Factor 55 1.5" fairlead. Have yet to do a pull with it.
I agree with you. The deformation is probably due to the weaker washers as well. If I upgraded just the washers I would probably have better results. But I've gone gr8 on everything. So we shall see in due time. The other option, I suppose, is adding more plate km the front and "reinforcing" the mounting holes. Make the new hole on the plate identical width to the bolts. Less "sucking in" action will occur.