Need advise about upper control arm shaft (offset or no offset)

Discussion in 'The whoa and the sway.' started by Cutlass, Mar 21, 2020.

  1. Cutlass

    Cutlass Platinum Level Contributor

    Glad, that I was able to pull my car out of the storage in time before the curfew went in effect. However, I cannot get it to an alignment shop to get the actual numbers for camber and caster.
    I want to use the time to redo the front suspension. I already have all parts at hand including regular and offset control arm shafts. I cannot measure caster, but measured camber with 1° negative on both sides. Here are some pics showing the "shim-situation" on both sides.
    IMG_0139.JPG IMG_0140.JPG IMG_0141.JPG IMG_0142.JPG
    It looks to me like there was not much sagging of the frame, as I have just 1° negative and still shims in front and rear. As there are on both sides more shims in the front, I would assume, that caster was set to factory specs (Negative). My conclusion would be to use regular non offset shafts, as I could just swap the shims from front to back in order to get more positive caster. Am I missing something?
  2. Cutlass

    Cutlass Platinum Level Contributor

    Spent some more time today, to try to become more accurate.
    Camber on both sides is 0.4° to 0.5° negative.
    Don't know what was wrong with my eyes yesterday, but here is how the shims are:
    LEFT: Front 3 shims 0.1 each, Rear 1 shim 0.1
    RIGHT: Front 3 shims 0.1 each, Rear 3 shims 0.1 each
    The Offset of the new shafts is 0.09" which equals 0.5° camber
    I feel like I will not have any issues to set positive caster, but I am afraid to get to much positive camber while going with the offset shafts.
    Your thoughts?
    Last edited: Mar 22, 2020
  3. knucklebusted

    knucklebusted Well-Known Member

    Generally, I would think you could move a shim from front to back without changing camber and giving you more positive caster. I would double-check toe though. I'm not sure about the offset shafts. I've never used them.
    Cutlass likes this.
  4. Bens99gtp

    Bens99gtp Well-Known Member

    You can use a piece of steel or pipe to set against the nubs of the ball joints stick out over the nut then use your angle finder to roughly measure caster.........just against the rotor or flat ofvthe brake drum will show camber............just make sure to have full weight on the control arms
    Cutlass likes this.
  5. Cutlass

    Cutlass Platinum Level Contributor

    I will bring the car to an alignment shop once I am done with everything, to get caster, camber and toe set accurately.
    Still, I am undecided which shafts to use. I am afraid of making the wrong choice and ending up pulling the upper arms again to change to the shaft needed to get the front end set appropriately.
    So what you guys think? One vote will be enough to tilt me one way or the other :)
    Last edited: Mar 24, 2020
  6. knucklebusted

    knucklebusted Well-Known Member

    If you have an old car, odds are you can use the offset shafts without too much of a problem but I'd bet it will align without them. Too bad they don't make those offset shafts with extra caster, offset out in the front and offset in at the back. That would give you good caster for sure.

    Be sure to ask for positive caster, as much as they can give you and a no more than 0 camber. Personally, I like -1/2° camber. With radials, these old cars can handle pretty good.
    Last edited: Mar 24, 2020
    Cutlass likes this.
  7. BuickV8Mike

    BuickV8Mike SD Buick Fan

    I went standard. The manual say 3/4" shim pack max. And I had 0.4" or so all around. You have lots of adjustment based on my 69 gs. Imo
    Cutlass likes this.
  8. wkillgs

    wkillgs Gold Level Contributor

    Agree.... there are not a lot of shims on Ralf's car. I don't feel offset shafts are necessary. However that could change once new bushings are installed, but I would use the standard shafts.
    Cutlass likes this.
  9. Cutlass

    Cutlass Platinum Level Contributor

    That confuses me. I understood that Offset shafts are used when you have a sagging frame, resulting in to much negative Camber (and there are no more shims left to be removed). Aren't Offset shafts made to adjust Camber towards positive?
    Anyway, I appreciate all your input, which confirmed my own tendency towards standard, non Offset shafts.

    I agree, but guess, that those guys rather sell tubular control arms which are designed for more positve caster in the first place. Those however are not an option for me, as I want the look to stay "original"
  10. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Couldn't an offset shaft be used in either direction? Depends on how you assemble it, which way you face the offset?
  11. 12lives

    12lives If it runs, it's done!

    Yes - they are marked, usually one side has "wheel side". But they can be installed either way.
  12. Cutlass

    Cutlass Platinum Level Contributor

    I thought about that, too. Black painted one is stock:
    IMG_0144.JPG IMG_0145.JPG
    Mechanically it will work. Have not done an accurate measurement, but my visual judgement says that you would get the same amount of offset, just towards negative camber.
    I watched a video of a guy from global west, stating that they would use the offset shaft for every stock rebuilt of A-bodies they do.
  13. BuickV8Mike

    BuickV8Mike SD Buick Fan

    So its basically 0.25" or so 'built in shim"?
  14. Cutlass

    Cutlass Platinum Level Contributor

    Actually, if installed they way intended, it is a 0.09" removed shim
  15. Cutlass

    Cutlass Platinum Level Contributor

    Got a question: How in the world am I supposed to get the rubber both stay seated properly on the lower ball joint? The lower section is always sliding back up. I have the kit from P-S-T.
  16. knucklebusted

    knucklebusted Well-Known Member

    You don't sweat it. The arm is fully extended and once you are at ride height it will settle in. It isn't a seal as in a tight seal. It is a seal as an umbrella. It is going to move around as the suspension travels. The only ones I've seen that really seal are on 4x4s and have crimped bands that fit into a groove on the ball joint.
    Cutlass likes this.
  17. Cutlass

    Cutlass Platinum Level Contributor

    Thanks Greg! I will follow your recommendation.
    I changed my mind in regards to offset vs stock upper control arm shaft and installed the offset shafts. I measured the geometry and did some "paper investigations" with sketches. It looks like the offset shafts gives you slightly more caster at only half amount of negative camber with the same shims in the rear, compared to stock.
    IMG_0175.JPG IMG_0176.JPG

    Doing the bushings was not as bad as I expected. Doing a little pushing with the help of my friend, the 20to press and some pulling with some threaded rod did the trick.
    IMG_0181.JPG IMG_0182.JPG IMG_0183.JPG
    For compressing the spring I bought a relatively inexpensive tool to be used inside the spring. Works very well, I upgraded it with an axial needle bearing for less friction. As I am full of respect of the huge potential energy stored in a compressed spring, I go with belt and suspenders, securing the spring for the time it is waiting for re-installation.
    I got the kit from PST and looking at the tie rods, they seem to be much more beefier, compared to what was installed. Do not know which brand was installed, but assume MOOG, as all ball joints where marked as MOOG problem solver.

    Attached Files:

    Last edited: Apr 12, 2020
    knucklebusted likes this.
  18. Cutlass

    Cutlass Platinum Level Contributor

    Finished installation yesterday and was able to get a spot on a hoist in a friends workshop and access to the proper equipment for front end alignment.
    It took me almost 4 hours, as I needed several rounds of adding/removing shims in order to get the alignment right.
    I knew beforehand that in order to get positive caster I would need to max out shim thickness at the rear bolts. In order to minimize the number of shims I had some shims water-cut out of different thickness of stainless steel.
    On the passenger side I used 19mm and on the driver side I even had to go slightly beyond the recommended max of 3/4" and used 23mm. That gave me about 3/4° positive caster on both sides.
    In regards to camber I needed 1mm shim on the passenger side and 12mm on the driver side, resulting in negative camber of 24' left and 42' right side.
    Toe in was set to 6' each.
    IMG_0215.JPG IMG_0216.JPG
    At least on the passenger side the offset shaft turned out to be necessary in order to not have to much negative camber. On the driver side I probably would have been better off w/o, as with stock shafts I would not have needed so many shims.
    I am not 100% happy with the result and the big difference in necessary shim thickness driver- vs. passenger side to set camber.

    Driving experience however improved quite a bit, which is not singular a result of the alignment. I switched to PST polygraphite bushings for lower and upper control arm and also the stabilizer bar. Also went with Bilstein shocks front and rear (the shocks installed had no dampening in rebound left at all :)).

    What I do not understand is, that now the car is lower on the left side, compared to the right side. It is visually obvious and is about 1" in difference.
    Any ideas / advice from you guys?
  19. IDOXLR8

    IDOXLR8 Senior Member

    Are you 100% sure the springs are in the correct clock position? Are they seated correctly at the top and bottom?
    Cutlass likes this.
  20. knucklebusted

    knucklebusted Well-Known Member

    I generally wouldn't get too concerned for at least a month. New springs sometimes take a little while to settle in. If it is still skewed in a month, I have usually used a twist-in spring booster to get the droopy side up to the same level. If it is the rear, they make bigger ones for those. You could claim the high side down to match the lower side. Either way, don't panic just yet.

    Good job on the alignment, too!
    Cutlass likes this.

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