I want to start from scratch on front suspension install. Order of operations

Kent mosby · Jan 26, 2022

I have a 1973 scamp.

RB 512ci, 440 source stroker kit with lightweight crankshaft, forged pistons, 10.83 CR. Trick Flow 240 heads, 440 source aluminum rockers 1.6RR, Trick flow single plane intake. Holley super sniper EFI, hyperspark ignition, coil and distributor. TTI 2 inch headers. Hughes 3000 stall converter. 727 transmission with transgo tf2 valve body mods. B&M Quicksilver shifter. Gear vendors overdrive to 8 3/4 rear end with 3.91 gears, braced in back. SS leaf springs. Competition engineering race shocks. Pypes exhaust 3" into 2.5 inch. RacePro mufflers. Mickey Thompson ET street SS Drag radials 255/60-15 27.3 inch) but going to 275/60-15 28.2 inch diameter. Current cam specs 244/252 @ .050”, 282/290 adv, .516”/.537” lift(1.5:1 rocker), 112 sep, .016”/.018” lash, Solid lifter from Oregon Cams

I currently have a
1. QA1 k member and dynamic strut rods
2. Comp engineering shocks all around
3. PST 1.03 torsion bars

I will be changing to
1. Viking double adjustable shocks all around, They arrive tomorrow.
2. 892/893 torsion bars

I have learned much about the front suspension since I first assembled this car from scratch and I may not have been as diligent with the details of assembly. What I would like to know is, If you were going to assemble from scratch, in what order and how would you do it.

My concerns are.
1. How to adjust the QA1 dynamic strut rods? They are in place but I did not adjust them. Do I do this without the shocks and brake calipers on or off? Suggestions.
2. torsion bars before shocks or after shocks?
3. I have read somewhere that you need to install something, and get the suspension weighted before you adjust and tighten things but I cannot remember what that was. Control arms, bushings, torsion bar, ride height. I cannot remember.
4. I also remember reading about rubber vs poly bushings, advice?

So many parts and I want to be systematic about it this time. I have a FSM but the sequence is not there. I can study the how to on many items but where do I start and in what order do I proceed? Of course in the end, I will set ride height and Align.

Kendog 170 · Jan 27, 2022

Kent mosby said:
3. I have read somewhere that you need to install something, and get the suspension weighted before you adjust and tighten things but I cannot remember what that was. Control arms, bushings, torsion bar, ride height. I cannot remember.

Some tighten control arms with weight on them. I never had. I just make sure they are in the general vicinity of their operation. It can prevent squeaks.
More importantly. NEVER , NEVER adjust torsion bars with weight on them. The thread will most likely strip and the car will come down on you. After adjustment bounce the car at the front bumper to help get the car settled and recheck ride height.
As for order assembly I'll let someone else chip in.
Good Luck sounds like a great build.

Kendog 170 · Jan 27, 2022

Would love to see some pics.

72bluNblu · Jan 27, 2022

1- The QA1 strut rods should be cycled through their full range of travel (bumpstop to bumpstop) to check for binding and then adjusted so there is no binding. I’ve found that the best way to accomplish that is with the LCA, spindle, and UCA assembled (spindles and ball joints attached to the control arms), but without the shocks, brakes etc. Basically you want the spindles and control arms assembled as that effects the binding, but leave off the shocks and any heavy stuff so it’s easier to cycle the suspension through it’s range of travel and detect binding. I also do this with the torsion bars installed, but the torsion bar adjusters removed.

2- Torsion bars before shocks. You may also find it necessary to disconnect the LCA from the spindle to get the LCA in the right spot to install the torsion bars.

3&4- this depends on the bushings. For rubber bushings, the LCA pivot nut needs to be torqued with the LCA at ride height. You don’t necessarily need weight on the LCA, but you do need the LCA in the same position as it will be at the final ride height. If you don’t know where that is, you’ll need to set the car down and make the ride height adjustment.

For poly or Delrin bushings you can torque the LCA pivot nut with the LCA in any position you want. Those bushings rotate on the LCA pivot pin, so the position of the LCA when the nut is torqued is irrelevant.

4- poly vs rubber depends on how the car will be used and your own preference. Rubber does not need servicing, but the rubber bushings currently available aren’t that great a quality so their fit and longevity is questionable in my opinion. Poly bushings require lubrication, so they should be installed with greaseable pivot pins and will need to be periodically lubricated, just like ball joints and tie rod ends. You already have adjustable strut rods to make sure the length is correct to place and control the LCA with the poly bushings. Your other option is Delrin bushings from @BergmanAutoCraft, which are made from a self lubricating material. Both poly and Delrin require a more accurate strut rod length than rubber, since they have less flex.

Dartswinger70 · Jan 27, 2022

I've done it but I dunno I remember putting the torsion bars in and sliding them back, bolting on the K frame then sliding the torsion bars forward, after that its lower control arms, then uppers, steering knuckle and shocks...did I miss anything? key thing with suspension is knowing when its loaded vs unloaded when things fly apart under spring pressure, that's when ya get hurt... yes lift the weight off the bars when ajusting, then lower down and recheck, you could count threads when taking apart and mark things like eccentric cams to get them back close.

P.S wait a minute I dont know if you can slide torsion bars back I may be thinking of a ford ranger, I remember sliding the K frame on the torsion bars then bolting it up its been a few years. I id pull trans missions out of ford rangers so I may be confusing the two.

Kent mosby · Jan 27, 2022

72bluNblu said:
1- The QA1 strut rods should be cycled through their full range of travel (bumpstop to bumpstop) to check for binding and then adjusted so there is no binding. I’ve found that the best way to accomplish that is with the LCA, spindle, and UCA assembled (spindles and ball joints attached to the control arms), but without the shocks, brakes etc. Basically you want the spindles and control arms assembled as that effects the binding, but leave off the shocks and any heavy stuff so it’s easier to cycle the suspension through it’s range of travel and detect binding. I also do this with the torsion bars installed, but the torsion bar adjusters removed.

2- Torsion bars before shocks. You may also find it necessary to disconnect the LCA from the spindle to get the LCA in the right spot to install the torsion bars.

3&4- this depends on the bushings. For rubber bushings, the LCA pivot nut needs to be torqued with the LCA at ride height. You don’t necessarily need weight on the LCA, but you do need the LCA in the same position as it will be at the final ride height. If you don’t know where that is, you’ll need to set the car down and make the ride height adjustment.

For poly or Delrin bushings you can torque the LCA pivot nut with the LCA in any position you want. Those bushings rotate on the LCA pivot pin, so the position of the LCA when the nut is torqued is irrelevant.

4- poly vs rubber depends on how the car will be used and your own preference. Rubber does not need servicing, but the rubber bushings currently available aren’t that great a quality so their fit and longevity is questionable in my opinion. Poly bushings require lubrication, so they should be installed with greaseable pivot pins and will need to be periodically lubricated, just like ball joints and tie rod ends. You already have adjustable strut rods to make sure the length is correct to place and control the LCA with the poly bushings. Your other option is Delrin bushings from @BergmanAutoCraft, which are made from a self lubricating material. Both poly and Delrin require a more accurate strut rod length than rubber, since they have less flex.

I have the Doctor diff front rebuild kit in rubber so I will lower to ride height. I will measure before removing everything and -correlate the spindle position at that height. I guess I could just measure the spindle CL to fender opening distance and use that for height when torqueing LCA pivot nut. Thanks for the clarity of order and details.

Kent mosby · Jan 30, 2022

All I finished today was the new torsion bars, adjusting the dynamic strut rods and installing the Front shocks. I took it for a quick drive but the front settled more that I thought it would and was on the bump stops. Back at the shop I jacked it up and adjusted the torsion bar adjusters. I will finish ride height after I finish the rear shock install.