Long arm mounting

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Jesus_man
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Re: Long arm mounting

Post by Jesus_man »

Event angle iron would work if you get it heavy enough.

Need some update pics!!
1973 Bronco, 351 SEFI, Locked, discs, 35's ZF-5spd and Atlas 4spd. 235:1 Crawl Ratio. It may be ugly, but it's slow.
http://www.ucora.org
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Justin
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Re: Long arm mounting

Post by Justin »

Gunnibronco wrote:Or add a section of C channel or rectangular box to the outside of the frame, to make it a bit wider where you need it.

We cam up with something way more needlessly complex, but it'll be strong and cool.
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Eck
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Re: Long arm mounting

Post by Eck »

Progress (with picture proof). Was able to get the arm brackets tacked in place. With what I could do with just myself, I was able to get the long arms more or less in (bolt hole is off by like 1/16").

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Both plumb bobs lined up just about perfectly.

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Everything looks pretty good as far is alignment.

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I drew up a quick idea of what Justin and I decided to do for the outside bracket reinforcement to the frame.


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Here are some shots of the bracket on the frame. I will have to cut the tack welds and get the bracket more flat, but you get the spacing.

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And then here is the 3D cutout of the bracket reinforcement. I will leave it up to Justin to help me design the actual plate that we weld to the frame.

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69 Wagon, 351W, Explorer EFI & Serpentine, ZF5, 35" tires, 3.5 SL, 2 BL, WARN 8274
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Eck
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Long arm mounting

Post by Eck »

We will also gusset the inside from the long arm bracket to the underside of the frame.

I'm also installing the taller shock buckets. I do have a question for those that have installed these. How do I want them to line up? Straight up and down to the ground? Straight to the angle of the arm? Looking for a little guidance. Also, how high up on the frame should I/ can I go?

There are also 2 bolt holes at the bottom- would it be a bad idea to drill 2 holes and use Grade 8 bolts to mount these as opposed to welding the bracket to the frame?

Thanks!

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69 Wagon, 351W, Explorer EFI & Serpentine, ZF5, 35" tires, 3.5 SL, 2 BL, WARN 8274
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Justin
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Re: Long arm mounting

Post by Justin »

The towers should follow the path of the shock at ride height. Bolting would be fine, but id probably use the holes for rosette welds
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Re: Long arm mounting

Post by Justin »

To figure out how high to mount them, lift your axle till something hits. Then mount the towers so the shock is fully collapsed minus half an inch. You can tack on the lower mounts and use the collapsed measurement of the shock.
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Eck
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Re: Long arm mounting

Post by Eck »

Justin wrote:To figure out how high to mount them, lift your axle till something hits. Then mount the towers so the shock is fully collapsed minus half an inch. You can tack on the lower mounts and use the collapsed measurement of the shock.


I haven't bought the front shocks yet because I have no idea what measurement I need at fully collapsed and at full travel. Now what?
69 Wagon, 351W, Explorer EFI & Serpentine, ZF5, 35" tires, 3.5 SL, 2 BL, WARN 8274
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Justin
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Re: Long arm mounting

Post by Justin »

Many shock manufacturers post measurements. If you're doing it right, you could fit short body bilstein 7100s in 14" travel. 12" is probably plenty of you're not going that high end.
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Jesus_man
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Re: Long arm mounting

Post by Jesus_man »

Justin has you lined out well with shocks but perhaps decide what shock you want to go with and then look at their measurements and design your upper mount from there. With a string attached to the bolt at your joint strung down the arm to where you want the shock to mount and then swing it up to see how the shock travels.

I'd weld the mount on the frame. Technically bolting will work but you can collapse the frame by over tightening unless you sleeve it. If you bolt it use a locking nut and big washers. Not nyloc but the ones with pinched threads.
1973 Bronco, 351 SEFI, Locked, discs, 35's ZF-5spd and Atlas 4spd. 235:1 Crawl Ratio. It may be ugly, but it's slow.
http://www.ucora.org
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Eck
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Re: Long arm mounting

Post by Eck »

Slept on it and today was able to get the long arms both mocked with bolts in place on both sides. Makes me feel much more comfortable about where everything sits.

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Centered the shock tabs where I'd like to mount the shock towers, welded them in place and arms are painted with chassis paint.

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69 Wagon, 351W, Explorer EFI & Serpentine, ZF5, 35" tires, 3.5 SL, 2 BL, WARN 8274
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Jesus_man
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Re: Long arm mounting

Post by Jesus_man »

Looking forward to that flex shot!!
1973 Bronco, 351 SEFI, Locked, discs, 35's ZF-5spd and Atlas 4spd. 235:1 Crawl Ratio. It may be ugly, but it's slow.
http://www.ucora.org
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Digger
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Re: Long arm mounting

Post by Digger »

Looking good so far!

On shocks, I will echo what others have said. Bilstein 7100s short bodys are a nice choice. F-250 shock mounts are the best bang for the buck. You'll want to mount them inline with the shocks at ride height, which is generally vertical.

I like having 14" travel shocks, but 12"s get the job done. I have 14s front and 12s rear.

Given your layout, it will be easier to package 12s. To get 14s on my truck, I needed the 2" body lift to get the shocks up high enough. This required welding a bracket to the frame that the F250 shock mounts bolted to.

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To figure out where to mount your shocks, you need to put weight on the suspension and figure out where the truck sits at static ride height. Then measure/look at various points on the front axle and figure out how much uptravel the axle has before it runs into something. You'll want to set your shocks so that there is still about 1/2" (1/4" MINIMUM) of travel left when the axle bottoms out.

Ideally, you want 4-6" of uptravel from ride height. This gives you enough travel to soak up bumps without constantly bottoming out. 4" minimum, 5-6" is ideal for our rigs.

Also remember to set your bump stops so that they engage the axle about 1" before it runs out of travel. The stops will compress quite a bit under a hard hit.
Cummins R2.8 diesel, ZF5, AtlasII, HP44/BB9, ARBs, coiled / linked suspension, 37" KO2s, full cage, bumpers, etc.
Build Thread: http://www.coloradoclassicbroncos.com/viewtopic.php?f=3&t=5420

Average 23.5 mpg, Best tank: 26.3 mpg
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Digger
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Re: Long arm mounting

Post by Digger »

http://cart.bilsteinus.com/pdfs/off-road.pdf

Here's a link to the Bilstein shock catalog. 12" and 14" 7100 stuff is on page 15


A 12" Short body Reservoir shock is 27.68" ext / 16.10" collapsed

A 14" Short Body Reservoir shock is 33.84" ext / 19.53 collapsed
Cummins R2.8 diesel, ZF5, AtlasII, HP44/BB9, ARBs, coiled / linked suspension, 37" KO2s, full cage, bumpers, etc.
Build Thread: http://www.coloradoclassicbroncos.com/viewtopic.php?f=3&t=5420

Average 23.5 mpg, Best tank: 26.3 mpg
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Eck
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Re: Long arm mounting

Post by Eck »

Random question- what have people used to paint the frame (touch up) after welding brackets to it and such? Hoping something that doesn't make that section stick out like a sore thumb.
69 Wagon, 351W, Explorer EFI & Serpentine, ZF5, 35" tires, 3.5 SL, 2 BL, WARN 8274
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Jesus_man
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Re: Long arm mounting

Post by Jesus_man »

A light coating of water and allow to air dry. That way it's rusty like everything else...

Otherwise a gray primer!
1973 Bronco, 351 SEFI, Locked, discs, 35's ZF-5spd and Atlas 4spd. 235:1 Crawl Ratio. It may be ugly, but it's slow.
http://www.ucora.org
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Digger
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Re: Long arm mounting

Post by Digger »

Spray bomb primer, then SEMI-GLOSS or SATIN black paint. I do this because it best mimics the E-coat that the OE's use. Flat black can be greyish and gloss sticks out too much.
Cummins R2.8 diesel, ZF5, AtlasII, HP44/BB9, ARBs, coiled / linked suspension, 37" KO2s, full cage, bumpers, etc.
Build Thread: http://www.coloradoclassicbroncos.com/viewtopic.php?f=3&t=5420

Average 23.5 mpg, Best tank: 26.3 mpg
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landshark
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Re: Long arm mounting

Post by landshark »

i usually wipe the area with Prep-all, then use etching primer, then satin or gloss rattle can black - usually Rustoleum .
1976 Bronco "Green, Yellow, whatever", 1969 Bronco "Red", 1972 Bronco Stocker "Kind of Blue/Grayish"
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Justin
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Re: Long arm mounting

Post by Justin »

I've been using whatever random crap needs using up. It's mostly hammerite.
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Eck
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Re: Long arm mounting

Post by Eck »

Milestone achieved. Front axle is re-installed and arms mounted. Everything lined up well and I can now move on to the rear axle swap!

Big thanks to Justin for lending me his welding capabilities and gratuitous crotch shot!!

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Inside gussets

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Outside bracket to frame

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It's got legs!!
69 Wagon, 351W, Explorer EFI & Serpentine, ZF5, 35" tires, 3.5 SL, 2 BL, WARN 8274
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