[Beery]

Okay, I've been building a bar for the front of my sierra to house a winch for what feels like forever now. The biggest issues I'm struggling with are what's available to work with on the front of a sierra chassis, how to package everything so it's compact, and design it in a safe and strong way but still keep it somewhat lightweight.

Gwagen's post in seanzook06's build thread has opened my eyes a bit to some issues I've potentially built into my bar (and a lot of bars I've seen) so this thread is basically just me showing what I've come up with, what I thinks wrong/right with it and Maybe it can help some people out, either by showing what to do, or what not to do, or just give some general ideas.

I've been researching various bars/winch mount designs for sierra's and there's very few I actually like - most seem to rely too heavily on the 4 bolts holes in the end of the chassis rail. Some even just use the inner 2, or something. I know of a car with a bar built like this that I wheel with quite often, and it genuinely worries me - every time the winch comes out I'm waaaaayy out of view. On the other hand, it doesn't seem like sierra's need a massively strong bar to be recovered successfully for majority of situations - even the ARB bar mounting system is a bit light on I think, just looking at it. that doesn't make me any less worried about it though.

Anyway, here's my attempt. Feel free to criticize the hell out of this thing I'm all for any feedback - I won't get upset. Keep in mind it's still in progress, there's some small parts missing and hasn't been finish welded.

So, here's my main base I started with - the raised sections on the side sit on top of the chassis rail, and then the middle steps down to sit on the tube crossmember.



Here's the mounts to pick up the holes in the end of the chassis rail.



They fit like so. Note - there will be crush tubes in the chassis rail with a long bolt between both mounts. The separate bolts shown here are just for mock-up.



These then got welded into the main winch mount.



I wasn't happy with just these mounts, so I picked up the two factory holes on the side of the body mount with another brace - this ties into the front plate and the main winch plate, as well as the top plate when it gets installed, so they add quite a bit of strength I think.





Even with picking up the body mount, I was worried about the centre of the winch plate bending upwards as it's only 3mm to try keep weight down, so it got a plate from the middle of the main winch plate, then down onto the lower flange - this plate sits hard on the tube crossmember (front side) This stiffens everything, but I also decided I would bolt it through the tube crossmember and pick up on another bracket behind the crossmember that will bolt on after the bar has been slid onto the chassis.

(The red outline represents a plate that will be added to stiffen the winch plate)





those through bolts go through the crossmember, basically clamping onto it, like so:



The entire bracket on the backside of the crossmember bolts on after the bar has been slid onto the chassis. The two Allen head bolts will bolt through the bracket, the winch plate (so, a total of 6mm steel) and then into the winch itself, sandwiching the whole lot together.



There's the bolts for the bracket. Just imagine the two right ones bolt into the winch, and the left one will just bolt through as is. The two front winch holes also had some 3mm strips welded underneath to double them up too.

I didn't simply drill through the crossmember and bolt through it though - I added some crush tubes. I'm not really sure if it's recommended to add a crush tube into, well, a tube.. Or if I should've clamped around the crossmember with some U-bolts, or just welded a bracket to the crossmember that picks up the rear of the winch plate. I had been staring at the front of it for ages trying to figure something out and decided I just needed to do something, so I went the crush tube route.

So, drill through and add the tube:



weld them in:



and grind them down, so the bar can sit flush to the crossmember again. In hindsight, I shouldn't have ground them to follow the curve of the crossmember tube, I should've just ground them flat with the face of the tube.



Here's my artistic picture showing all mounting points: (you can see one of the crush tubes in the bottom left chassis rail - these will be added to all 4 points)



11 bolts in total - 3 in the crossmember, through crush tubes, 4 (two each side) through both sides of the chassis rail through crush tubes and 4 (2 each side) that tap into the side of each body mount.

Overall, I'm relying a lot on welds here, which isn't the best, because as you can see I'm not much of a welder. There is a lot of weld holding it together though (or will be). I'm also not thrilled with the crossmember mounting - a flat plate sitting against a round tube just doesn't sit right with me, there's not much surface area to clamp onto there.

Those flaws considered, I think it should still be quite strong. I don't think it's going to fail, or be a safety hazard. But if anyone thinks otherwise, I'm keen to hear your thoughts.

I feel quite good about weight - the use of various holes and cut-outs means we're currently at 13.2kg's, which I think is pretty reasonable - I have some small braces to make for behind the rear wings, but I will also add some holes behind the number plate etc.. so I don't think that number will move much once the bar is fully complete. The entire bar is 3mm sheet, If I was to do it again, I would use some 2mm sheet for various things to bring weight down more - some braces, the wings and top panel for example. for reference the factory bar and chassis outriggers weigh 8kg.

[Eddy]

lookin' good, but still need way more speed holes

[seanzook06]

I am no one to judge seeing I am having to make a whole new bar due to mount and winch issues, but it definitely has more mounting points than mine ever did

[Beery]

There will be more holes eddy, just no more visible ones

I think that's the key for mounting on a sierra seanzook - lots of mounts to spread the load out. None of these mounts are strong enough on their own but when they all work together I think it will be adequate.

Some exceptions would be maybe if a RUF conversion is done, then the end of the chassis is usually/can be beefed up a bit, however I'd still like to see more mounts. A note on that too - if your planning to make a new bar, and also planning a RUF down the line (as said in your build thread) you may want to plan around that or do the RUF first, because the chassis extension is going to affect how and where you mount the bar. I'm not committed to do a RUF yet, but if I ever change my mind, it's going to be a nightmare/a lot more work to accommodate the chassis extension into my bar. With that said, it's not the end of the world if you need to modify the bar at a later date. Part of the reason I haven't done a RUF yet is that I'm not confident in my abilities to do important welding on the chassis yet, and if you're not either, I wouldn't go rushing into a RUF just so you can put a winch on. Just something to think about.

[tanshi]

I would be concerned still with the 3mm plate that the winch actually bolts too tearing through with heavy load. perhaps some more 3mm , 50mm od washers to just stop that from occuring?

[Beery]

I'll throw up another picture tonight tanshi, but there is some ~30x50mm rectangular washers welded under the front two winch mounts. The rear of the winch bolts through that entire rear bracket, so that's doubled up 3mm the entire length of the winch plate. These pictures are probably a bit confusing to anyone who didn't build it.

I'd rather have the winch feet facing forward tbh (like how ARB do it) so there's less pressure on the bolts, but the bar would have to be a lot taller and stick out further to get strength into the front plate with gussets etc.

[tanshi]

Ahh ok, yeah that sounds allright then.
My winch mount on my racing buggy is 6mm strips welded on the side of 3.2mm wall tube and it will not move so this should be heaps on a sierra

[seanzook06]

Beery wrote:

There will be more holes eddy, just no more visible ones

I think that's the key for mounting on a sierra seanzook - lots of mounts to spread the load out. None of these mounts are strong enough on their own but when they all work together I think it will be adequate.

Some exceptions would be maybe if a RUF conversion is done, then the end of the chassis is usually/can be beefed up a bit, however I'd still like to see more mounts. A note on that too - if your planning to make a new bar, and also planning a RUF down the line (as said in your build thread) you may want to plan around that or do the RUF first, because the chassis extension is going to affect how and where you mount the bar. I'm not committed to do a RUF yet, but if I ever change my mind, it's going to be a nightmare/a lot more work to accommodate the chassis extension into my bar. With that said, it's not the end of the world if you need to modify the bar at a later date. Part of the reason I haven't done a RUF yet is that I'm not confident in my abilities to do important welding on the chassis yet, and if you're not either, I wouldn't go rushing into a RUF just so you can put a winch on. Just something to think about.

thanks for the advice, I will be doing a RUF hopefully in the next few months, I have all the suspension parts lying around, just need more time to plan. my thought is that between a beefed up front chassis and spreading the load out a bit more like you have, my bar will probably be strong enough, although I will probably still tie it back to the front shock mounts the same way gwagen has done.

[Gwagensteve]

Whilst I think that bar is mounted plenty strong enough and is very elegantly designed and built, along with being light, one of the reasons I tied my bar back onto my shock mounts is that I don't like how bendy the front of a Sierra chassis is. Put a pry bar in the end of the chassis with the chassis supported on axle stands back at the firewall and you'd be amazed how flexible the chassis is. I liked the idea of tying it in further back making the whole front of the chassis a bit stiffer. I was especially thinking about when your winching with a big side or up angle on the rope.

All those 11 bolts are in a very tight plane viewed from the side - having something further back would be nice. That'd be my only comment. I do appreciate your car flys a lot more under the radar than mine so big obvious braces and things (or cutting up inner guards, for example, to fit them) aren't really appropriate.

[Beery]

Thanks for the comments.

I agree, I'd love to tie it into something further back, but I really don't know what. I looked at it for ages trying to figure something out. It's not really guard cutting that worries me getting it back to the shock mount for example, it's more the fact the car doesn't have a body lift (and I don't want one) so that 2 inch gap where your brace sits isn't available to me. If I were to add a brace it would have to go outside of the body mount I think, which would basically be supporting the wings of the bar instead of the centre winch mount, although that would help, I'd like it in closer to that main structure. Not to mention the factory shock mount is back way further than yours, it's not as sturdy, or as simple to mount to. there's a pretty straight shot at the engine mount on the passenger side that I thought about, but the steering box and everything else ruins any chance of getting a brace through to anything on the drivers side - I guess one brace on the passenger side would help it to resist bending forwards.

In regards to chassis stiffness, do you think it's the braces back to the shock mounts adding stiffness, or simply the fact that the actual bar is adding a lot of strength across the very front of the rails? I wouldn't think the braces would add much to stop the chassis twisting, only to stop the bar pulling forwards/downwards.

While it's not ideal, I've seen some much less sturdy bars do some successful winching on a sierra (as said before, even the ARB bars are a bit worrying to me) so I'm confident it will be fine.

Also, out of interest, Do you know what your bar weighs Steve?

[Brenno]

Very well built and thought out, bravo!

[Fingers]

I can't comment on how it is structurally, but it looks fantastic