Warn 12k, Stock Bumper, How To (1 Viewer)

[fish2live]

So you did mount it feet down, then? That's an issue with the winch feet and body itself, aside from all mounting considerations. Isn't that body aluminum?


Well, the final result in the OEM bumper looks stunning!

Agreed - final result is great. On the feet down...
E, how did you mount your M12 in your 80? Was it feet down?

I just got of the phone with Warn and talked to a tech that has been there for 17 years. He sees 1 or 2 M12K's every year with broken feet from "feet down" mounting. The feet are aluminum and are a potential point of failure if the load is pushed hard on the M12K. However, he said failure of the feet is almost always associated with bad winching technique such as no snatch block when needed and especially people using the winch AND the truck to pull at the same time - thus over-peaking the load substantially. He wouldn't go near saying that feet down was "ok" - but he agreed that with good winching technique and common sense the chances of breaking the aluminum feet would be very greatly minimized. He was very surprised ARB recommends (or at least says it will fit) the M12K and that they only offer a feet down mouting. But maybe they did some additional testing... doubtful...

He said the M12K was desinged in the early 80's and hasn't really changed. My though is with THAT long of time in the field that if they were seeing significant issues with this particular problem Warn probably would have undergone a re-design by now? maybe... or at least that's what I'll tell myself for now..

anyway - winch safely fellow M12K "overkillers!!"

 

[sleeoffroad]

Actually the M12 can be mounted feet down, however you have to have a flange in front and capture the front bolts as well. So it is really a 90 degree mount.

I would also suggest you grab the frame bolts that the tow points attach to. Those front pieces that you bolted to is not very strong and you have a good change to pull and deform them.

 

[fish2live]

Yes, good point Slee - he mentioned that as well - feet down is ok but as long as you also mount the front bolts as well

 

[HawkDriver]

Actually the M12 can be mounted feet down, however you have to have a flange in front and capture the front bolts as well. So it is really a 90 degree mount.

I would also suggest you grab the frame bolts that the tow points attach to. Those front pieces that you bolted to is not very strong and you have a good change to pull and deform them.

How exactly do you mean a flange in front and capturing the front bolts? There are 4 bolts holding the feet down. And two additional ones holding the forward edge to the crossmember/fairlead support.

I did think that those frame ends were a little on the weak side but my thinking is that the with the unit being tied into the secondary crossmember it would have to give for those to budge. I just don't see how they could deform without that piece giving in as the angle of the new front crossmember will not allow itself to cave. If it were flat bar across the front in the vertical plane only I can see how it would deform easily, although doubtful with it being tied into the second member, but I don't think it is possible with this angle iron configuration having compound angles. I'm not an engineer so I really have no scientific data to back up my theory, just my best judgement having looked at all the parts and pieces involved in a fair amount of detail. I guess if they deform then I'll have to go back to the drawing board.

I do like that suggestion of reinforcing it using those lower hook mounts, I hadn't thought of that. I appreciate the thought you guys are putting into this idea. Thank you all.

 

[e9999]

of course, I mounted mine feet forward...


when you mount it feet forward correctly the rope passes between the 4 feet. That means all the feet are mostly subjected to compression stresses (they are squished against the mount). Aluminum can do very well in compression of course. So that's good. OTOH, if you mount it feet down with the line going "sideways" you get huge torque put on the feet. (And even way more so -what, 4x more maybe...- if you're going out from the top...) The 7000 ftlbs I was talking about or whatever the real figure is.... The torque will result in not only serious shear on the front bolts and feet (not good) but also on tension on the 2 rear bolts because of the leverage. You are then basically holding a good chunk if not most of the pull with the shear resistance of the thread in the 2 rear aluminum feet.

And, yes, of course, if you block the front top, you're again using the aluminum compression resistance to your benefit. But you got to have good solid front mounts for that.

There is a huge difference in physical issues between the 2 ways (front or down) of mounting, not just semantics, IMHO.

And coming off the top is making things seriously more stressful, I would think. (Good to ask Warn about that aspect of the feet down approach, maybe?)

I truly hope all goes well. Just be careful out there.

 

[HawkDriver]

On the topic of safe recovery techniques; only an (with lots of extra cash) would use his winch to snatch some one out with.

I'll keep an eye on it and seek out the weaknesses and continue to develop it from there.

I appreciate having this place to have a discussion like this with others who are committed like me. Keep the comments and criticism coming. Interesting discussion with you guys. Thanks.

 

[HawkDriver]

of course, I mounted mine feet forward...


when you mount it feet forward correctly the rope passes between the 4 feet. That means all the feet are mostly subjected to compression stresses (they are squished against the mount). Aluminum can do very well in compression of course. So that's good. OTOH, if you mount it feet down with the line going "sideways" you get huge torque put on the feet. (And even way more so -what, 4x more maybe...- if you're going out from the top...) The 7000 ftlbs I was talking about or whatever the real figure is.... The torque will result in not only serious shear on the front bolts and feet (not good) but also on tension on the 2 rear bolts because of the leverage. You are then basically holding a good chunk if not most of the pull with the shear resistance of the thread in the 2 rear aluminum feet.

And, yes, of course, if you block the front top, you're again using the aluminum compression resistance to your benefit. But you got to have good solid front mounts for that.

There is a huge difference in physical issues between the 2 ways (front or down) of mounting, not just semantics, IMHO.

And coming off the top is making things seriously more stressful, I would think. (Good to ask Warn about that aspect of the feet down approach, maybe?)

I truly hope all goes well. Just be careful out there.

Oooh, that makes sense. I wish this thread existed before I started this.

 

[e9999]

and, finally, although it sounds like you may have done that already, if one mounts it feet down, one may want to clock the drain so it's down cuz they come set up for feet forward, reportedly (don't remember about mine).

 

[HawkDriver]

Yes, I mentioned that in a previous post. I also sealed the top one, both of which had no plug from the factory.

 

[sleeoffroad]

How exactly do you mean a flange in front and capturing the front bolts? There are 4 bolts holding the feet down. And two additional ones holding the forward edge to the crossmember/fairlead support.

The winch has 4 bolt holes on the bottom and two in front. As long as all the force is not on shearing the 4 bottom bolts you should be fine. Picture winch from the side, pushing against the upper lip of a big angle iron. I think you have it like that but not against the upper lip (where you mounted the fairlead to.

I did think that those frame ends were a little on the weak side but my thinking is that the with the unit being tied into the secondary crossmember it would have to give for those to budge. I just don't see how they could deform without that piece giving in as the angle of the new front crossmember will not allow itself to cave. If it were flat bar across the front in the vertical plane only I can see how it would deform easily, although doubtful with it being tied into the second member, but I don't think it is possible with this angle iron configuration having compound angles. I'm not an engineer so I really have no scientific data to back up my theory, just my best judgement having looked at all the parts and pieces involved in a fair amount of detail. I guess if they deform then I'll have to go back to the drawing board.

A sever downward pull will put a lot of leverage on them and the crossmember will not come into play. It looks like you are close to the frame holes with your cradle, just extent some metal to the back and grab those bolts as well. Maybe a small channel or angle to give some upwards/downwards support.

ARB bumpers attached to those points on Tacoma's (as well as the side) and had a tendency to pull the nuts out of the metal.

I do like that suggestion of reinforcing it using those lower hook mounts, I hadn't thought of that. I appreciate the thought you guys are putting into this idea. Thank you all.

Yes, thing sideways or up and down pulls. If you are stuck with the nose up, you are going to be pulling downwards pretty hard.

 

[sleeoffroad]

of course, I mounted mine feet forward...


when you mount it feet forward correctly the rope passes between the 4 feet. That means all the feet are mostly subjected to compression stresses (they are squished against the mount). Aluminum can do very well in compression of course. So that's good. OTOH, if you mount it feet down with the line going "sideways" you get huge torque put on the feet. (And even way more so -what, 4x more maybe...- if you're going out from the top...) The 7000 ftlbs I was talking about or whatever the real figure is.... The torque will result in not only serious shear on the front bolts and feet (not good) but also on tension on the 2 rear bolts because of the leverage. You are then basically holding a good chunk if not most of the pull with the shear resistance of the thread in the 2 rear aluminum feet.

And, yes, of course, if you block the front top, you're again using the aluminum compression resistance to your benefit. But you got to have good solid front mounts for that.

There is a huge difference in physical issues between the 2 ways (front or down) of mounting, not just semantics, IMHO.

And coming off the top is making things seriously more stressful, I would think. (Good to ask Warn about that aspect of the feet down approach, maybe?)

I truly hope all goes well. Just be careful out there.

e9999 is correct that it should not be mounted only feet down. I am not sure ARB does this. I would have to check, but I think the bumpers for the 100 that has the feet down mounting might be limited to 9k lbs winches. There is some discrepancy in their application guides and actual install guides.

 

[fish2live]

well - ARB very clearly says the M12000 is suitable for 3 out of the 4 bars on the 100 series - http://www.arbusa.com/uploads/PDF/accessorizeYourRig/toyotaLandCruiser100Lexus470.pdf

And I know for certain on my '03 the Sahara does NOT have an option for feet forward - it's only able to be mounted feet down and there is NO option for securing the 2 front bolt either - it's just the 4 on the bottom and that's it.... thanks ARB..

 

[e9999]

I imagine that ARB is saying that such and such winch will fit and can be mounted, not so much that the winch will not tear itself off the mounting bolts... They probably figure that's Warn's problem....

 

[HawkDriver]

I do find it interesting that it is claimed that this particular winch from warn should be feet forward when almost every other one of theirs is mounted feet down. What is so different? This one is cast with 8 bolt holes which would make one think it's twice as strong as the other designs and intended to be used in this way.

I am concerned about the over the top routing and the leverage placed on the rear bolts. I'm thinking of adding the holes in the lower rear support tabs for the two additional rear feet bolts, that should take care of the chance of just pulling the threads right out of the original two. And I'll look into reinforcing that cradle into the tow point holes for the hard downward pulls, as I was mostly envisioning straight pulls. I wish there was some anchor point above to tie in to but there really isn't anything. As a last resort I might have to chop those frame end caps off and restructure them with some more solid steel.

I think that the forward face is supported adequately by the fairlead ears and that adding holes in the uprights for those forward face bolts, upon completion of the aforementioned reinforcements, would be overkill.

 

[fish2live]

Hawk - it's not the mounting Warn is concerned with, it's the alum feet on the winch body. The guy said feet down are fine for the "small body" winches (9.5XP and smaller) but on the "medium body" (12k and up) he said the actual alum feet on the winch body are really pushed to their limit if mounted feet down due to all the torque stresses mention in this thread. I do feel that if you're not cranking the hell out of it things will be ok - or using your rig to pull at the same time you're winching.... WINCH CONSERVATIVELY !!

anyway - I like to be super secure and prefer overkill - but in this case I just don't think I'm going to pull the whole damn set-up and re-mount with a custom feet forward config... I think I'll just wait to do that if/when the feet down fail...

 

[e9999]

one way to look at it:


pretend you mount your winch on the vertical wall of your house with the 4 "lower feet" bolts. Say the wall is very strong and holds the bolts firmly.

Now, hang a couple (!) of cruisers from the line and stand under them. Do you trust the aluminum "feet" to not deform and let the cruisers fall on your head...?

 

[fish2live]

e - did you do a custom feet front mount on your ARB in your 80?

 

[HawkDriver]

Ok then if I'm thinking correctly, if I were to change it all and mount it feet forward then it would make no difference the way the line spools over the drum correct? In order to keep the fairlead in the same spot that is.

Oh jeezuz, if this is the case maybe I'll just reconfigure the whole thing and start building that bumper around it. FUN!!!!!!!! Then we can re-title this thread ...how NOT to...

 

[e9999]

e - did you do a custom feet front mount on your ARB in your 80?

not really

 

[e9999]

Ok then if I'm thinking correctly, if I were to change it all and mount it feet forward then it would make no difference the way the line spools over the drum correct? In order to keep the fairlead in the same spot that is.

Oh jeezuz, if this is the case maybe I'll just reconfigure the whole thing and start building that bumper around it. FUN!!!!!!!! Then we can re-title this thread ...how NOT to...

well, the full drum is probably 8" or so. So depending on which way the rope comes out, ideally, you'd want to move the fairlead more up or down for better alignment. If your fairlead is way off vertically, you will put very large vertical forces on it when pulling on the rope.

before you redo everything, couldn't you try to see if you can build up the front upward bars a bit, maybe tying them backward to the frame or crossmember for more strength. That may be all you need to get good support up front and doing more of a 90o mount as Christo calls it (still not as good IMO as a feet forward mount, though)? The better the winch body is blocked there, the stronger the whole thing will be. But there again, coming out on top or bottom will make a difference in the stress.

Basically, it's always the same thing with Engineering: When is good good enough? All a subjective matter depending on the needs...

isn't it amazing how quickly things can get more complicated than anticipated, when designing stuff...? A good reason to throw out ideas here to get feedback before you start building? (Then of course you have to live with the annoying anal types like me.... sorry.... )


All, the same, present aggravation notwithstanding, who knows, maybe without this back and forth, your winch might have flown out, destroying your front end, pulling chunks of your frame with it, going through a parked original Bugatti, and maiming the pregnant girlfriend of a married class-action lawyer...