Custom Rear Bumper + Wheel Carrier

[guzzla]

I made this rear bar over Christmas and figured some might like to read how I went about it and maybe inspire others to have a go. Like the front one I made earlier, this rear bar was a combination of what I wanted to achieve with the design regarding departure angle clearance, rear quarter protection and over all looks. I also took inspiration from other custom rear bars, many right here on IH8MUD

As always, even the best laid plans can change as a project evolves and this rear bar was no different. Here's some build pics (lots) and a bit of a description along the way...

Starting with a blank canvas
http://www.servimg.com/image_preview.php?i=418&u=14684539

I have a 25mm body lift and have lifted the long range tank to gain better departure clearance and thus lessen the chances of damage. I needed the underside of the rear bar to clear the top of the fuel tank so I tacked on 2pc of 30mm angle. This helped to support the rear bar during construction and ensured it went back into the same position each time.
http://www.servimg.com/image_preview.php?i=419&u=14684539

After much convincing from a guy I worked with, I got a packet of these silver pencils. Old mate was a fitter/machinist/welder from way back and totally raved about how good these pencils were to work with black steels. He was dead right, they are bloody awesome and $hit load more accurate, easier to see and longer lasting than chalk, pencil or texta. They're only about $10 for a pack of 3.
http://www.servimg.com/image_preview.php?i=420&u=14684539

A project like this that gets taken on and off so many times needs to have a reference point to build from. I marked the centre line of the chassis and took all measurements from that. Unfortunately, it may just highlight discrepancies in body panel alignment
http://www.servimg.com/image_preview.php?i=421&u=14684539

I also wanted to take advantage of the factory fixing points. Mine had rusted and the threads destroyed so I had to fix them. Cue two, 10x1.5mm x 40mm threaded rod couplers...
http://www.servimg.com/image_preview.php?i=422&u=14684539

Grind down for a friction fit onto the 20mm hole I drilled into the original fixing points...
http://www.servimg.com/image_preview.php?i=423&u=14684539

Bevel the outside edge for better weld performance and tap into position...
http://www.servimg.com/image_preview.php?i=424&u=14684539

Weld, grind and paint and you're good to go. Note: to protect the threads from weld splatter, I screwed in a old bolt covered in grease. The bolt got binned but the threads were as good as new. repeat process for all four holes.
http://www.servimg.com/image_preview.php?i=425&u=14684539

 

[guzzla]

The plan was to fold as much as possible out of one sheet. For the main bar, I used 5mm sheet steel. Starting with the top rear, I began to scribe it into the body work



From there, with careful measurements ,I was able to mark out all the folds needed to make it up out of one piece. I may have checked my measurements more than once


I used the score, fold and weld method since I don't have a folding machine. It is a time consuming process but is accurate if you take your time with neat, straight cuts and consider for allowance like metal thickness lost when folding and cutting the right side depending which way you want to fold to go. Basically, always score along the outside of the bend.


A quick test fit showed it was mostly all going according to plan. The flaps shown here are turn downs that are intended to hang a bit lower than the sub tank for added protection. In the past, a few steep drop offs have tagged the back edge of the tank, denting it. I then trimmed them back so they protruded past the lower edge of the tank about 12mm.


Part of the plan was to keep it close to the body while still offering good protection. I was also chasing that custom form look so was willing to take a few chances with design. Here, I'm folding in the lower section toward the external corner so it doesn't have that boxy look.


Here, I'm tacking into position the 3mm sheet to complete the sub tank protection. These go from the bottom edge of the turn town at the tank, back up to the lower, external corner of the bar. They act as reinforcement but also to give the rear of the bar clean, tapered lines.


Here it is in position ready for grinding.

 

[guzzla]

A couple of the captive nuts in the lower part of the chassis had seen better days and needed to be replaced. After a bit of a scout around in the garage, I found these 2 nuts - they were from a shopping trolley I scavenged parts from after finding it in the scrub. Funnily enough, the thread was an exact match. I knocked the old ones off with a cold chisel and now these just sit inside the chassis after a lick of paint.


I didn't want the same old side wing setup most rear bars have and was intent on doing things differently. I was also sick to death of having mud caked up in the wheel arches and through the rear of the chassis. I really wasn't sure how it'd work out but decided to run with it. To begin, I needed something solid to build off, so I made a mounting plate that bolted to the 4 captive nuts in the lower part of the chassis.


Then, using some 3mm sheet, I got stuck into it...

Out of the one piece, the sides turn up. Here, I'm just playing with angles and aesthetics while keeping rear quarter protection in mind.


I then scribed another piece of 3mm sheet around the rear quarter panel. I made a cardboard template first but it still took a while to get spot on.


Trimmed to size and in position. A tip for young players is to leave things a little longer than you might need them. It's easier to cut it back 3 times than it is to join it. Also, sometimes things get overlooked and you realise you shouldn't have cut it where you did.


And repeat on the other side. Might pay to check it against your first template - if your 80 is like mine, you'll have to make a new one


I then fitted some internal gussets. Small gussets and braces in the right positions allow you to use much lighter materials for the same, if not more strength. These were all fully welded later on.


I then removed the bar and did some more welding. I also decided to beef up the fuel tank protection which would also serve to tie in the lower section of the side wings where they bolted to the chassis. While it may not be shown. The 3mm plate was fully welded to the 5mm plate I made earlier to mount to.


And some more fancy metal work to blend it in. Note the angle tacked into position at the far end of the wing - this will be used to mount the mud flaps to. I've also checked in the recovery points.


This shows the full size of the plate that forms the recovery point. 10mm plate IIRC.

 

[guzzla]

Next, it was time to start on the wheel carrier. I ordered a spindle, bare hub and bearings from here: Tire carrier hinge kit - Jeeptubes.com

Cut to length and in position...


Beveled the bottom...


Gusseted and welded for maximum stiffness.


For the main swing arm, I used 75x50x4 RHS. Here, I've scribed the end for a neat fit to the hub. Ive also marked where it needs to be bent to follow the curve of the rear bar.


Here's the arm now bent. I ran several layers of weld over it to beef it up and blend it back in.


I also ran a heap of welds to beef up the join and also build it up for a neat finish. I'm about halfway here.


All blended in and with the gas strut and brackets tacked on. This is a 500nm strut and needed to me compressed with a clamp. It sure is a strong sucker :shock:


Swing arm in position showing it following the rear bar.


For the vertical arm, I half lapped it onto the horizontal for added strength and to avoid extra gusseting and to also give me added clearance to the tailgate. I welded in one gusset under the outrigger that supports the 35in tyre - just to be sure.


I had to mark out the spacings for the wheel studs. To say I struggled working out the spacings was an understatement but I got there in the end


See



One last test fit and tune before finishing the grinding and painting it.

 

[guzzla]

After endless days of cutting, grinding, welding and more grinding, it was a welcome relief to go shopping for paint.


After a quick once over with some builders bog to fill in any remaining pinholes and minor imperfections, it was time for several layers of high build primer before blocking it back to a silky smooth finish. At this point, I lathered the inside areas with the zinc based paint for added rust protection. You can also see other bits and pieces that got fitted and weren't shown earlier.


The weld on, over centre latch is from Universal Engineering Supplies.

Here, you can see the extra gussets welded in. Fully bolted up, the whole bar is rock solid.


Then 2 coats of metal primer...


While the paint dried, it was time to fix a few bits on the cruiser since it'd be a while before I have access to them again.
The lower rear quarters copped several layers of sound deadening paint.


I also had to fix a hole left by a long gone grommet
Now you see the bottle top...

Now you don't


If you stick your hear right up in the rear quarters, you'll see a hole on each side about the 75mmx75mm. This area is prone to fill up with mud and water.


After a good wash out with the hose the day before, it was time to stop crap getting in there. With a bit of rubber cut to size and some FixIt sealant adhesive (very good stuff)


Done. I did leave a bit of a gap at the bottom to let any water drain out that might get in there. Once dried, I coated the whole area with several coats of body deadener.


I knocked up a bracket to hold the number plate and number plate light. This is the LED light I used

 

[guzzla]

In keeping with not doing what everyone else does, I steered clear of gloss black. With several coats of metallic charcoal fully carefully applied, it was time for the final fit up. I was very happy with the result. It just needed a few more finishing touches




A mate bent up some 1.6mm alloy checker plate and I trimmed it to size


I drilled and tapped (M6) the top of the rear bar...


And screwed the alloy into position



Next I had to come up with a neat way to keep the swing arm open. After a bit more head scratching, I came up with this - cheap and effective

 

[guzzla]

To finish off, I have a few more detail pics of the bar itself and some other things that bring the whole show together.

I wanted to do as much as possible in stopping the mud caking the wheel arches and getting into places that make cleaning / removal difficult. I considered screwing rubber sheeting in but that was going to look too untidy. I like the occasional fiberglass job and knew the finished product would be neat, strong and removable. I don't have any progress pics, but I just used several layers of masking tape to bridge the gaps between any voids. I then sprayed the whole lot in a mold release and applied 2 layers of matting. Once dry, I applied another 4-6 layers before leaving it to fully dry. I then carefully removed it, trimmed it to size (it's better to make it a little bigger and cut back after as it gives you a neater, thicker edge) and tidied up any irregularities and imperfections, before giving them a couple of coats of body deadener and reinstalling and fixing off with some self tappers.

This is the DS rear. I made it overlap under the side wings to keep as much crap out as possible. I also ran it out to the edge for the same reason.


This is the PS rear. Note how it also extends right up the top to protect the fuel filler as one piece. I left the factory plastic guard in place and taped over it before applying the fiberglass. Once complete, the OEM unit got binned and the fiberglass cover fixed into position. I will soon be making another fiberglass section to fill in the opening of the forward area of the rear wheel. This will overlap the rear panel just a little.


Here, you can see how I've wrapped the fiberglass under to but into the face of the mudflap.


This is the finished clearance around the rear quarters, about 12mm. Because the side wings are tied back to the chassis, they are super stiff and will require a fair belt before it hits the panel. If I drove like I use to, I'd have allowed a little more clearance You'll notice I also brought the side-wings outside and past the flare. Every rear flare I've torn off in the bush as been because it got hit on the inside edge. The intention is this will go some way to deflecting the offending branch or rock face.




The mudflaps are a fiber reinforced rubber - not cheap but it wont tear. I bought a 1m sheet, cut them slightly larger than needed, punched a series of holes in the top of the flap and fixed them by drilling and tapping the angle. (I am yet to make a sandwich plate to go over the face of the mudflap for better holding/clamping pressure) Once both were in position, I trimmed them to suit. They are held off the back of the tyre with stainless steel chain and a few eyelets. I used stainless so it wouldn't rust and it also doesn't rattle like mild steel chain does. I've made them so I can quickly tie them further back in really rough terrain.


Thanks for reading

 

[rolliges]

Very nice work.

Love the wings, big enough for a step.

 

[hakalugi]

nice job, enjoy it.

 

[neatus]

Wow Guzzla, that is a bad ass bumper bro. Great job and great write up! I'm gonna go start cutting some metal now...

 

[PDoyle]

You made it look easy........

 

[ERG80]

WOW! really nice work!

 

[bruff]

Dude, you have quite the set of skills! Nice work!

 

[Dgurley2000]

Congrats on finishing! How many hours do you estimate you spent on this project?

 

[bricat]

I think I'm a coming round your place this weekend.. NICE JOB

 

[TRDCRUISER95]

Great job!!!!!

 

[BlackLS1]

very amazing detailed work. i like the way it came out.

 

[guzzla]

Thanks all, the compliments are much appreciated.

It took about 6weeks all up but that's not working on it the whole time.

but I'd say there is 21 days solid work if you didn't have distractions. I really couldn't begin to tell you an hour quantity - a fair bit of time was spent just looking and thinking about what would work and how. With projects like this, you have to think 10 steps ahead all the time.

Working from the centre point quickly showed that there were measurement discrepancies from one side to the other - the body, not the chassis (previous body damage repairs etc. Like scribing the tops of the side wings to the body, I had to make 2 templates since they weren't the same profile and it took about 2hrs to scribe each one -that's half a day before I even get onto anything else. There is also the best part of a week just in grinding, smoothing, rounding corners and blending in. IIRC, the wheel carrier alone took about 2 days. Just heaps of measuring, checking and re checking. There's also about 5kg of mig welding wire and a full bottle of Argo-Shield - remember, every single join or gusset was fully welded, even all the internal and external corners.

There are times when everything seems to take forever and you can spend a whole day and achieve nothing, other days you get a heap done. Some days I just wanted to but the old one back on, but I knew I had to keep pushing and I really was having fun along the way - I love these projects as much as they piss me off sometimes.

 

[guzzla]

Very nice work.

Love the wings, big enough for a step.

Absolutley, they were part of the design criteria. The old tube bar was a real bitch to try and stand on when getting stuff on or off the roof or even just to wash the roof. With this bar, I was able to get the side wings to prioject out enough to offer good rear quater protection, while also giving me a flat area big enough to stand on.

I'm actually thinking of putting a strip of grip tape on the outside edge to prevent potential slippages when wet.