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Sky's Offroad Design Super Duty RSK Install

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Gary Lewis

Re: Sky's Offroad Design Super Duty RSK Install

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What I'll do today is tighten the lower shock bolt w/o having the upper part of the shock in the tower. That'll show where the shock wants to go w/o being influenced by the tower.

But that will show where the shock wants to go with no load on the suspension. Does the axle rotate any as weight is put on? Or does it just go up and down?

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

ArdWrknTrk

Re: Sky's Offroad Design Super Duty RSK Install

Administrator

Gary, the spring now pivots at the front, and when the arch flattens, obviously the shackle deflects and the axle moves rearward

That's kind of the whole point of a RSK....
The axle is allowed to 'go with' the bump instead of being pushed into it.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Gary Lewis

Re: Sky's Offroad Design Super Duty RSK Install

Administrator

Yes, now I remember!

In fact, as the weight comes onto the suspension when the truck comes down off the lift the axle will move a bit to the rear. That being the case, we want any potential mismatch of the shock to the tower to accommodate the rear movement. Meaning that the shock should naturally fall to the front of the shock tower when the truck is on the lift and then move to the rear as the weight comes on.

But, will the axle rotate any when the spring deflects? Won't it rotate such that the pinion comes up a bit as the spring flattens?

Gary, AKA "Gary fellow": Profile

ArdWrknTrk

Re: Sky's Offroad Design Super Duty RSK Install

Administrator

It may, some.
But both sides of the spring flatten, so really just the pivoting on the front spring eye.

And the panhard (without heim joints) helps, even if only a little.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Gary Lewis

Re: Sky's Offroad Design Super Duty RSK Install

Administrator

A couple of things. First, I called Erik at Sky. He has the u-bolts in stock and will get them out this morning, his time. Sure good to do business with him.

As for the torque question, he said he doesn't torque the spring or shackle bolt to spec. Instead he tightens them until they start compressing the bushings.

After that I bolted the shock into the lower plate and torqued the bolt down to spec to ensure the shock is firmly held in place at the bottom, and shot this video. And, while this shows that the shock goes into the tower perfectly, this is with no weight on it. So I asked Erik, and he suggested that I be patient and wait until I have the engine in and the truck on the ground. So, I guess I'll wait.

Gary, AKA "Gary fellow": Profile

Gary Lewis

Re: Sky's Offroad Design Super Duty RSK Install

Administrator

And, I've realized that the snippet of the FSM I posted earlier didn't have all of the torque specs in it. But this one does, I think.

Gary, AKA "Gary fellow": Profile

salans7

Re: Sky's Offroad Design Super Duty RSK Install

As soon as you first mentioned the shock tower my first thought was that there is no weight on the truck currently. I definitely agree with Eric that you need to weight (

) until the truck is on the ground with full load.

Gary Lewis

Re: Sky's Offroad Design Super Duty RSK Install

Administrator

salans7 wrote

As soon as you first mentioned the shock tower my first thought was that there is no weight on the truck currently. I definitely agree with Eric that you need to weight () until the truck is on the ground with full load.

Yep.

So here's the issue: the sway bar. The pic below shows the sway bar installed on the 1995 front clip. And with no engine the end links fit. But they aren't about to fit on Big Blue. They are about 4" too short. I assume that's because of the "lift" the RSK provides. But I can't find extended links on the Sky site. Am I missing them?

I'm not too worried as I don't think I even want to run a sway bar. But, I'll probably drill the holes in the frame to allow it to be installed should I want to do so, and now is the time to do the drilling.

Gary, AKA "Gary fellow": Profile

salans7

Re: Sky's Offroad Design Super Duty RSK Install

Just cut and weld an extension into the stock end links.

Gary Lewis

Re: Sky's Offroad Design Super Duty RSK Install

Administrator

Yes, I'm thinking about an extension. But I was kind of thinking about those that might not have a machine shop with which to make the extensions.

My thinking is that I'll take a piece of rod the same diameter as the stop on the end of the link against which the rubber bushing goes. I'll center-drill and tap it on the lathe to screw onto the link on one end and take a piece of all-thread on the other. Screw the extension on the link and screw the all-thread into the other end, both with Loctite.

Basically, it just screws on and extends the sway bar link.

Gary, AKA "Gary fellow": Profile

Bruce moose4x4

Re: Sky's Offroad Design Super Duty RSK Install

On mine I just found a piece of tubing that fit over the rod and extended my links that way.
Also I am confused as to why they started using a pan-hard bar. All the early dana 60's did not use them? My 1978 doesn't have one. Just two leaf springs hold it in place.

Bruce aka Moose--1978 F250 LWB Flareside, Dana 60's w/ 4:10's, 460, c6

Gary Lewis

Re: Sky's Offroad Design Super Duty RSK Install

Administrator

A piece of thick-walled tubing would work. It would have to be pretty strong tubing, but if it had the right ID to be tapped to then screw onto the original end link it would be easier than starting with a rod.

As for the panhard rod, I don't know when they started using them. But my reading says that w/o a track bar the frame/body moves when you try to turn, not the tires & axle. And, it is possible to get into a death wobble. But that's just what I read.

Gary, AKA "Gary fellow": Profile

Gary Lewis

Re: Sky's Offroad Design Super Duty RSK Install

Administrator

Well, the next question becomes which Pitman arm to use. The one on Big Blue is shown on the top and the one from the '95 F350 is the bottom one:

85/ F250 - - 4/W/D 4600 lb. front axle "From 1/85" E5TZ 3590-C (marked E5TA 3590-BA) 5 1/8" long c/c w/1.4" drop
85/ F350 - - 4/W/D "From 2/85" E5TZ 3590-A (marked E5TA 3590-CA) 6" long c/c w/.7" drop

So I called Sky and they said for sure to use the F350 one as it gives a better turning radius due to the length. And with no extra lift on the truck the drop difference won't matter.

Then, as I was about to tackle removing the Pitman arm the spring u-bolts came in from Sky. So I diverted to installing them. Here's sort of a before and after. Which do you like best?

Gary, AKA "Gary fellow": Profile

Gary Lewis

Re: Sky's Offroad Design Super Duty RSK Install

Administrator

Oh yes, I also pulled the F250 Pitman arm, installed the F350's, and torqued the nut to 200 ft-lbs. Somehow I think that much torque used to be easier to generate.

Gary, AKA "Gary fellow": Profile

ArdWrknTrk

Re: Sky's Offroad Design Super Duty RSK Install

Administrator

...depends on how long your cheater bar is...

You do realize there are such things as torque multiplying wrenches and ratchets, don't you?
1200 foot pounds is easy to generate.
It just requires going around and around, a lot.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Bruce moose4x4

Re: Sky's Offroad Design Super Duty RSK Install

In reply to this post by Gary Lewis

That makes sense on the panhard bar. There is quite a bit of difference in the frames pre 80 and post 80. You build is looking good. keep up the good work.

Bruce aka Moose--1978 F250 LWB Flareside, Dana 60's w/ 4:10's, 460, c6

Gary Lewis

Re: Sky's Offroad Design Super Duty RSK Install

Administrator

Moose - Thanks!

Jim - I'm using a digital torque wrench, so no cheater allowed. (But I do have pieces of pipe laying around that do serve as cheaters when I need them.)

Speaking of torque, I was a bit blown away with how easy it was to change out the Pitman arm. I got the air impact out 'cause it is supposed to be torqued to 170 - 230 ft-lbs. However, the nut came off pretty easily. Then I put the puller on and used a breakover to tighten it up before using the impact on it - and the Pitman arm moved, long before I got "down on it". So that Pitman arm wasn't fully seated on the splines.

But I will assure you this one is ON.

Gary, AKA "Gary fellow": Profile

ArdWrknTrk

Re: Sky's Offroad Design Super Duty RSK Install

Administrator

A 6:1 multiplier between ratchet and socket would mean you apply 33.3# and the nut is torqued to spec.

How hard is that?

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

ArdWrknTrk

Re: Sky's Offroad Design Super Duty RSK Install

Administrator

This is 3.3:1 so you'd need 66#', but it IS available Prime from delivery tomorrow.. 😁

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

ArdWrknTrk

Re: Sky's Offroad Design Super Duty RSK Install

Administrator

In reply to this post by ArdWrknTrk

Dangit!

The forum is REALLY screwing me up with inserting images, links and attachments lately..

https://www.amazon.com/Neiko-03715B-Torque-Multiplier-Foot-Pound/dp/B0017K5ARU

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

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