Alignment problems?

Chassis, Suspension and wheels

  1. BudW

    BudW Moderator Staff Member

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    Are you not able to get your FMJ into alignment (not enough provision for positive Camber)?
    There are three fixes (that I know of):

    The first option
    is to remove the upper control arm support plate (or plates, if both sides are needed) – Red arrow. Once plates are removed, you need to grind on or lengthen the slot (towards the wheel or outside of car) - Just don’t carried away with the grinding. Deburr the slots, then reassemble the suspension.
    77 FSM pg 2-12c n.jpg

    Option two is to remove the upper control arms, dissemble the arms and replace the upper cross shaft/bar with an offset shaft (gold arrow, above). New control arm bushings are installed at same time (which most of us might need new bushings, anyway). Here is a picture of an offset shaft (made (or were made...) by a few different companies):
    Rare Parts RP15177.jpg
    Part numbers are (and there might be others):
    Rare Parts RP15177
    Moog K7091
    TRW 13261a

    Note: it is “best” to tighten the upper control arm bar nuts to specs (110-ft/lb. or 489 nm) after bushing replacement, when car is at “ride height”. If this is not done, the bushing is twisted and will wear out faster.

    Option three (my recommendation) is based off a Chrysler TSB (Technical Service Bulletin). I thought I had a copy of this of this TSB in my records but couldn’t find it. This data was copied from Alldata:
    1983-1987 Gran Fury, Diplomat & 5th Avenue

    Subject
    Insufficient Positive Camber Adjustment

    Index
    FRONT SUSPENSION

    Date
    December 22, 1986

    No. 02-05-86 REVISION A P-4482
    This bulletin supersedes Technical Service Bulletin 02-05-86, which should be removed from your files. The rear spacer part number has been corrected to PN 4014353, and labor operation numbers and time have been assigned.

    SYMPTOM/CONDITION
    Insufficient positive camber adjustment.

    PARTS REQUIRED
    1 Spacer, Front Suspension Upper PN 4014352
    Control Arm Pivot Support - Front

    1 Spacer, Front Suspension Upper PN 4014353
    Control Arm Pivot Support - Rear

    REPAIR PROCEDURE
    This repair outlines the installation of upper control arm support plate spacers.

    1. Loosen the caster/camber adjusting nuts (not necessary to remove them).

    2. Raise car and remove wheel.

    3. Loosen shock absorber upper nut (not necessary to remove).

    4. Remove the two (2) support plate bolts at the front end of the plate.

    5. Loosen the two (2) rear bolts enough to slide the front spacer (longer of two) between the support plate and the frame.

    6. Align the holes in the spacer with the holes in the support plate and frame.

    7. Insert the two front bolts and start threads. Do not tighten.

    8. Repeat Steps 5 through 7 for the rear spacer (shorter of two).

    9. Torque the four (4) support plate bolts to specification (65 foot pounds).

    10. Torque the shock absorber upper nut to specification (25 foot pounds).

    11. Replace wheel on car.

    12. Lower the car and adjust the alignment on the side where the spacers were installed according to the procedures and specifications in the service manual.

    NOTE: THE UPPER CONTROL ARM SPACERS ARE TO BE USED ONLY AS A SET (1 LONG AND 1 SHORT) ON THE SIDE WHERE THEY ARE NEEDED. UNDER NO CIRCUMSTANCES ARE SPACERS TO BE STACKED TO GAIN ADDITIONAL POSITIVE CAMBER ADJUSTMENT.

    POLICY: Reimbursable within the provisions of the warranty


    TIME ALLOWANCE:
    Labor Operation No. 02-10-55-90 . . . . . . . . . 1.8 Hrs.
    Includes Shim One Side and Align Front End

    02-10-55-91 . . . . . . . . . 2.5 Hrs.
    Includes Shim Both Sides and Align Front End

    FAILURE CODE: 50 - Improper Adjustment


    Decades ago, I had a handfuls of the spacer plates mentioned in Option three. Now I don’t. I do plan on getting an example of each and placing the measurements here (once obtained). I “believe” the spacers are 3/16” (4.8 mm) thick – but I see no reason why 1/4” (6.4 mm) thick stock wouldn’t work. I do recommend replacing the four (per side) support bracket to K-frame bolts with grade 8 bolts – if using these spacers.
    4014352 FMJ Suspension spacer ft.jpg
    4014352
    4014353 FMJ Suspension spacer rr.jpg
    4014353

    Option four does not allow for more adjustment – but does help strengthen the upper control arm support plates (helps prevent it from bending). This is part of a recall for F-bodies:
    1977 Plymouth Volare Suspension Recall 78V097000

    Action Number: N/A

    Service Bulletin Number: 78V097000

    Report Date: May 01, 1978

    Component: Suspension

    Potential Units Affected: 1,100,000

    Manufacturer: Chrysler Corporation

    Summary: Possible fatigue failure can occur in the frame support plates (front suspension pivot bar support plate) that connects a portion of the front suspension to the vehicle frame on the involved vehicles.

    Consequence:

    Remedy: The dealer will inspect support plates for indications of failure and, if necessary, will replace the plates. Additional support brackets will also be installed to reinforce the support plate at the pivot bar attachments.

    Notes: Vehicle description: passenger vehicles. System: suspension; frame support plate. Consequences of defect: under certain driving conditions, this failure could affect vehicle directional control, particularly during heavy brake application. This will result in loss of vehicle control without prior warning and a vehicle accident.


    This is a picture of the additional parts already installed (on my ’77 Volare) - yellow arrows:
    20190524_140259 m.jpg
    If you can find these parts (used, and in decent condition), this is a great way to beef up any FMJ suspension system.


    Factory alignment specifications are:
    From my 1977 FSM (Factory Service Manual) for F and M-body
    1977 Alignment Specifications.JPG

    From my 1986 FSM (for M-body)
    1986 Alignment.png

    To recap, "official" ride height is from bottom of lower control arm to ground.
    BudW
     
    Opticon77 likes this.
  2. SixBanger

    SixBanger Well-Known Member

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    Great summation for alignment options and specs.

    Maybe a silly question. But a higher ride height, would that effect the settings of the alignment? For European roads I like more an higher height / stiffer pre-load.
    And measuring the ride height is from ground to center line of the lowest bushing?
    Tnx!

    1.PNG
     
  3. BudW

    BudW Moderator Staff Member

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    Chrysler has pretty much always used an un-equal length control arm (upper vs. lower control arm length).
    Yes, ride height will affect alignment angles.

    Camber is mainly a “tire wearing” angle. When you see cars with inner tread (or outer tread) on tire worn off – then camber angles are off. In many cases, the camber is off is because of a lack of enough adjustability.

    Caster has a bigger affect on how a car handles and less so on tire wear.
    That said, any alignment angle being off can and will affect tire wear.


    When aligning a car, the first step is to always check tire air pressure(s), and adjust as needed.

    Second step – on cars with adjustable ride height, like FMJ’s, is to check and adjust the ride height.
    Note: if you recently performed a ride height check or adjustment – always tell the alignment shop to not worry about that, for some people prefer the front end set lower than normal (or higher).
    If you are considering driving the car faster than police deem necessary, then a lower front ride Hight might be a good thing. If you live out in the country and/or plagued with potholes (or other obstacles), a higher ride Hight might be favored.

    The adjustment of caster and camber is performed next.

    Last step is to adjust toe-in, for pretty much an adjustment to any of the above items, affects the toe-in.
    Centering the steering wheel falls under the toe-in adjustment.


    The FSM’s (Factory Service Manual) says to measure from bottom of lower control arm bushing – or your “A” in picture in post just above this one. To be honest, it is hard enough for us old-timers to craw under the car to get measurements. To also figure out the “center-line” of a bushing would almost be too much to calculate (to me).

    A tip; ALWAYS ask for a copy of the finished alignment worksheet. Compare those numbers vs. the numbers in first post (above). Especially look at the camber numbers.
    If those numbers are off, ask why. If they say lack of adjustability, then you need to visit the first post of this thread, perform modification(s) and take car back to finish the alignment. Otherwise, you WILL have tire wear issues.
    BudW
     
  4. M_Body_Coupe

    M_Body_Coupe Well-Known Member

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    Nice stuff...heck, I've got the TSB book here and the plates themselves...I've attached the TSB scans, but the measurements of the plates will have to wait until this weekend...

    02-02-80 - UCA Tower Shims P1.jpg

    02-02-80 - UCA Tower Shims P2.jpg