Alignment problems?

[BudW]

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.

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):

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.
EDIT: the factory shims are verified to be 1/4" think (and not 3/16" as I had suspected).

4014352

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:

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

From my 1986 FSM (for M-body)

To recap, "official" ride height is from bottom of lower control arm to ground.
BudW

 

[SixBanger]

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!

 

[BudW]

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

 

[M_Body_Coupe]

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...

 

[BudW]

Attached is copies of the specifications that I measured from original shims. I have the material to make my own shims – but my detached garage is too dang cold to work in, currently.

These are ¼” thick steel. These are measurements that I took myself.

BudW

 

[SixBanger]

but my detached garage is too dang cold to work in, currently.

Someone at work always say, cold is a emotion you can ignore. Also 3x T-shirt 2 hoodies and a jacket keep you from frozen. But, still all metal and tools keep cold to your fingers..

But great additional information to this threat.

 

[89.Fifth]

I can make some CAD files from these drawings in case anyone wants them CNC'd or Machined

 

[Aspen500]

I bought NOS shims from Ebay and they do the trick for the excess neg. camber.
Must be getting lazy in my old(er) age. Ten years ago I'd have made them myself at home and saved some money.

 

[volare 1977]

Yea, I bought some of those shims also instead of making them. It was just one less thing to work on.

 

[BudW]

Well, I guess I don’t see the advantage to buying them for $30 (or whatever) each and I need eight (two cars, four each).
I purchased a metal chop saw and a bench grinder (my old grinder was made in the ‘30’s, I think) – for a number of projects (not just for this). Then bought a 6’ x 1½” x ¼” piece of steel then attempted to cut my first section off. Shortly after I started to cut, I got called away to take teenage daughter to the mall. Hadn’t gone back into the deepfreeze sense.
BudW

 

[BudW]

I can make some CAD files from these drawings in case anyone wants them CNC'd or Machined

That would be a very good idea to do. I feel there will be a greater need for these shims than supplies currently allow for.
BudW

Edit: If making a cad drawing (or whatever) I would make the two holes just a smidge larger than 1/2".
For those of who has drill presses, a 1/2" drill bit is about as big as you can find.

 

[volare 1977]

I actually found some cheaper when I bought mine but surely it would have been cheaper to make them myself.

 

[89.Fifth]

That would be a very good idea to do. I feel there will be a greater need for these shims than supplies currently allow for.
BudW

Edit: If making a cad drawing (or whatever) I would make the two holes just a smidge larger than 1/2".
For those of who has drill presses, a 1/2" drill bit is about as big as you can find.

Would you say it's 0.5 Smidges or 0.625 Smidges?

But in all seriousness, what would be a good decimal inch diameter?

 

[BudW]

The bolts are 7/16” in diameter.
I have had to file down a couple of these (factory shim) holes to get them to work from production tolerances (K-frame and/or shim). They were close but just not quite there.
If a person was getting these machined, I would say 0.550”. I think, for most of us, finding a 9/16” drill bit would be hard to find (and expensive) if a person found one.

Thank you,
BudW

 

[80mirada]

I use a step bit to size the holes when making brackets and spacers at home, but I do have a 9/16 inch bit also. They aren't particularly hard to get, but if you do buy one buy a good one, they tend to be cheaper in the long run

 

[MBDale]

Bud. Tell me what I need to do. All new front end. Alignment shop told me I need the frame pulled.

 

[AJ/FormS]

oops

 

[M_Body_Coupe]

Bud. Tell me what I need to do. All new front end. Alignment shop told me I need the frame pulled.
View attachment 39051

I'm assuming they meant to say "...re-align K-frame, by having it rotated clock-wise" (as looking down on the car from overhead).

My thinking is: the pass side wheel is too far forward, the driver side is too far back (someone check please if I have my +ve / -ve caster terminology right here).

Yeah, clearly a few degrees off here and there really isn't an easy way of fixing that w/o moving some parts.

Here are the final alignment specs on my coupe. Was lucky enough to have the car completely stripped when re-building. So all new parts, and well, the before & after numbers weren't all that far off, so eye-balling it with a few measurements here and there actually gave me a pretty good result.

Car tracks perfect, no pull, absolutely superb ride for this type of a brick!

 

[BudW]

I recreated your sheet to make it a bit more readable:

( ') are degrees and ( " ) are inches. Green is good, red is not.

My first question is – which is something that 99% of wheel alignment shops do not check, is did they check the front ride height? The ride height is he very first thing to check on our cars – because the other alignment angles will all be affected.
Sense this something most shops do not do, I prefer to check and adjust the ride height myself - and is something that anyone here can do.

The procedure to set ride height is in the PDF page, below.

The SAI (Steering Axis Inclination) is the big item that is off on your sheet.
Sense our cars have unequal length upper/lower control arms – by raising the ride height, SAI will change as well. How much of a change depends on how low car is currently sitting. Here is what my ’77 FSM (Factory Service Manual) says about SAI:

It says it is not adjustable – which technically is correct, but front ride does affect that angle.

If you check the ride height and not much change took place – then not much change would have taken place with the SAI either. I have a feeling that getting that ride height set correctly will fix that concern.


Now onto the rear suspension. The differential is not parallel with the chassis – which is making the car go down road a bit sideways. This is not uncommon with most all cars made in this time frame due to production tolerances and so forth. A simple fix. You will need to purchase (or make) shims to go between the rear leaf spring front support brackets where they attach to the chassis (just in front of the rear tires). BAC Rear Axle Shims - Bergman Auto Craft makes shims which are 1/8” thick.

I would recommend getting two shims. Note: if you only use one, let me know for I need to purchase one myself – and I’ll buy it from you. Jack the car and support the chassis with jack stands. The rear tires do not need to be off the ground – but it will be more helpful they are off the ground. Loosen the 4 nuts that attach that front bracket (the nuts do not need to be removed). Insert the shim from bottom going up, then retighten those nuts. I would soak those nuts a few times before removing with rust penetrating oil for those can be difficult to remove. If one of those studs break, then you have more work to do.
This repair will not affect the front alignment – except the steering wheel will no longer be centered. With our steering gears as loose as they are – a person might not notice it being off, slightly.

Hopefully this helps,
BudW

 

[Aspen500]

I see thrust angles on solid rear vehicles off by that much, or more, even low mileage ones a couple years old, so build tolerance is not perfect to this day. Independent rear are often way out of whack but, those are adjustable for rear toe at least (camber on some also) so you can get it to zero in most cases while still keeping toe correct. Just an FYI thing anyways.

Front drive cars with engine/suspension cradles often need shifting to even out camber and/or caster, which is rarely adjustable on it's own. Not all can be moved but some can. An FMJ k-frame has limited adjustment but maybe it'll have enough to get the job done on your car. That's providing the car isn't "bent" from a crash at one time in it's past, or something similar. That caster split probably makes the car pull like a son of a gun.