Start Your Go-Fast Build-Rear Suspension

VintageIronFab
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Re: Start Your Go-Fast Build-Rear Suspension

Post by VintageIronFab »

Ive got three questions for the rear shock mounting:
1.) In the rear with the shock mounts raised in the crossover tube configuration-- what is the compressed length that is basically maxed out that is correct? The shocks I am looking to buy are right at 20.5" I kind of noticed that the mounts typically dont put the shock literally in the corner of the floorboard. The corner of the floorboard should get you a couple more inches I would think.

2.) Do the lower factory mounts hold up well or do they tend to have metal fatigue issues?

3.) When building a 2-link it appears that the upper frame mount is just below the front leaf spring mount and dropped about 3" below the frame-- the lower axle 2-link mount is about the same and straight down to the ground. Does that seem like a fair description? Also n the link mounts basically on the Yikes build he just installed everything and then plug welded them when the tires are back on the ground. I am thinking that is the lower links in a nutshell.

Thanks!
Matt
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Travisfab
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Re: Start Your Go-Fast Build-Rear Suspension

Post by Travisfab »

1) My Solo set up has the cross tube up and as tight as possible. I'm able to use a 12" King, most people run 10's

2) My lower mounts have held up well. I added a weld to them though as well
VintageIronFab
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Re: Start Your Go-Fast Build-Rear Suspension

Post by VintageIronFab »

Is there a consensus on how important the 2-link kits help out the rear suspension? I dont have a 2-link on the rear at this point but the rear end is out and cutting out 4 tabs and welding them onto the rear end is much easier pre-install and painted up. From what it looks like to me-- the lower mounts are simply a pair of tabs welded to the housing that go in-between the u-bolts. Please let me know if I am way off
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baja-chris
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Re: Start Your Go-Fast Build-Rear Suspension

Post by baja-chris »

No there is not. My opinion is they are a waste and not needed on a well setup suspension. Been running my bronco for 15 years without rear links and have no desire to have them. Also raced a Stock Full for a couple years that worked great and won many races without links.
Not sold at all on them. And there are many folks who feel just as strongly that links are needed. We can at least agree there is no consensus!
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ESHALLBETTER
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Re: Start Your Go-Fast Build-Rear Suspension

Post by ESHALLBETTER »

baja-chris wrote:No there is not. My opinion is they are a waste and not needed on a well setup suspension. Been running my bronco for 15 years without rear links and have no desire to have them. Also raced a Stock Full for a couple years that worked great and won many races without links.
Not sold at all on them. And there are many folks who feel just as strongly that links are needed. We can at least agree there is no consensus!
What constitutes a "well set up" rear suspension? I don't know how to word that without sounding like a smart ass, sorry! Spring under? spring over? shackles? the leaf pack? a certain combo of things?
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Re: Start Your Go-Fast Build-Rear Suspension

Post by VintageIronFab »

yea Chris what constitutes a good setup on a rear suspension-- barring all the full race 4-link stuff through the bed??
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baja-chris
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Re: Start Your Go-Fast Build-Rear Suspension

Post by baja-chris »

one that does not need links
VintageIronFab
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Re: Start Your Go-Fast Build-Rear Suspension

Post by VintageIronFab »

You really are known for hammering your shit-- I would like to know what your opinion on the rear suspension components would be..........
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baja-chris
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Re: Start Your Go-Fast Build-Rear Suspension

Post by baja-chris »

how about leafs of the correct rate, sleeves and bushings that fit right, shackles that cycle and shocks that are valved to control them.
i like the narrower leafs (2.5" vs. 3.0") as they allow for better traction and more body roll and you get a thicker pack for the same rate which is less prone to unwanted movements (s-bends).
also leafs that move freely on the pivots which is achieved by machining steel sleeves and bushings that can be fully torqued tight and yet still allow non-binding rotation without unwanted side play.
use 4130 thick wall stock to machine your sleeves and use delron or nylatron for bushings. note that the sleeve will be a little wider than the finished width of the bushings in the leaf eye (maybe 0.1 over or 0.050 per side). make your own parts for perfect fit or give your lathe operator the dimensions and tolerances you want.
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ESHALLBETTER
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Re: Start Your Go-Fast Build-Rear Suspension

Post by ESHALLBETTER »

Thanks! I appreciate the insight that comes with experience.
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ChaseTruck754
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Re: Start Your Go-Fast Build-Rear Suspension

Post by ChaseTruck754 »

baja-chris wrote:also leafs that move freely on the pivots which is achieved by machining steel sleeves and bushings that can be fully torqued tight and yet still allow non-binding rotation without unwanted side play.
use 4130 thick wall stock to machine your sleeves and use delron or nylatron for bushings. note that the sleeve will be a little wider than the finished width of the bushings in the leaf eye (maybe 0.1 over or 0.050 per side). make your own parts for perfect fit or give your lathe operator the dimensions and tolerances you want.
It's amazing the difference this can make.
The bushings (poly) that came in my "link killer" 64's are laughable as the sleeves are about .125" - .250" NARROWER than the bushings and all are different sizes. If the bolts are torqued with these sleeves it'll bind the bushings & they won't really work as bushings. Many people don't notice or get this though. The slightly oversized sleeves put an end to this.

As for the delrin - I like it for the shackle pivot.
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DirtFiend602
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Re: Start Your Go-Fast Build-Rear Suspension

Post by DirtFiend602 »

Great piece of info!
cs_drums
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Re: Start Your Go-Fast Build-Rear Suspension

Post by cs_drums »

ChaseTruck754 wrote:It's amazing the difference this can make.
The bushings (poly) that came in my "link killer" 64's are laughable as the sleeves are about .125" - .250" NARROWER than the bushings and all are different sizes. If the bolts are torqued with these sleeves it'll bind the bushings & they won't really work as bushings. Many people don't notice or get this though. The slightly oversized sleeves put an end to this.

As for the delrin - I like it for the shackle pivot.
My 64 kit came the same way. It is all coming apart before the next trip. reworking the front hangers, spring prep and all new bushings set ups. I am going with delrin on the lower shackle cause with the poly it was actually flexing to the point of the shackle hitting the hanger.
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ChaseTruck754
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Re: Start Your Go-Fast Build-Rear Suspension

Post by ChaseTruck754 »

yup. Poly at both leaves & shackle is too much flex sometimes. So poly in leaves & delrin for shackle pivots tightens things up just enough I'd think.
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Re: Start Your Go-Fast Build-Rear Suspension

Post by cs_drums »

Also the mil rap in rubs metal on metal on the front hanger. I am thinking of making the sleeve as well as the shoulder on the bushings wider. More wiggle room.
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Re: Start Your Go-Fast Build-Rear Suspension

Post by VintageIronFab »

this is good stuff!
toddz69
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Re: Start Your Go-Fast Build-Rear Suspension

Post by toddz69 »

VintageIronFab wrote:this is good stuff!
You already knew about the sleeves/bushings dimensions stuff :)

Todd Z.
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tcm glx
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Re: Start Your Go-Fast Build-Rear Suspension

Post by tcm glx »

baja-chris wrote:one that does not need links

Hey Chris, I'm curious if you have run a 2 link at one point or not.
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baja-chris
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Re: Start Your Go-Fast Build-Rear Suspension

Post by baja-chris »

long time ago on my Ranger but I took it off and tossed it.
have seen them professionally done on broncos by top shops that did not cycle correct if you took the leaf pack down to a single leaf (and put a spacer in to maintain location) so you could cycle it, and the link itself caused bad motions as the rear cycled, the rear does not cycle in a pure arc with leafs because the length from the eye to the rear end changes as the spring arch reduces and yet the link wants to cycle in a pure arc, it does not grow to match what the leaf is trying to make the rear end do. the path along the leaf spring from the pivot eye to the rear end is not a straight line, it has arch to it and that arch changes as the spring cycles so the distance changes. not much and probably taken up by all the slop of stock rubber or poly bushings but when that slop is removed, there is nothing to take up this mismatch so it forces the spring to unnatural shape. if i wanted to run links, then i'd go back to rubber bushings and i'd rubber mount the links too so it would all be so sloppy that it would work (and might need links because of this). just my opinion, i'm sure there are guys with links who disagree so keep that in mind.
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Re: Start Your Go-Fast Build-Rear Suspension

Post by Wrightracing.net »

I am with Chris on this one. I have been running the same setup on my 86 Bronco for almost 20 years less the 4130 and used dom. It took me a few years of running Rancho shocks, upper shock mount from John at Autofab and then running Bilstiens that were valved much better for the Bronco. I even turned my own bushings out of Acetal Rod aka Delrin.

Chris
On my new rebuild or the rear I have a set of National Leaf sping race packs that were a spare set for Josh's stock full F150.

I did try the old Rancho kicker traction shocks and did nothing to help. That was back in the early 1990's.
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