This spring, I learned that my my 65 Barracuda's idler and pitman arms have some play in them. After finally settling a warranty claim from Just Suspensions for a bad lower ball joint, I got a new pitman arm (PN 20112) from them and a new Moog idler arm (PN K414) from Rock Auto. While I have everything apart, I'm also going to replace my urethane UCA bushings with a pair of Moog offset bushings (PN K7103).

The pitman arm seems straightforward to replace but the idler arm is harder. It looks like I'll have to raise the engine a couple of inches to get enough clearance for the k-frame bolt. The local alignment shop isn't really familiar with old Mopars so I thought I would set the front height on a friend's hoist to make sure it's done right beforehand.

Some questions:

• How do I ensure that the steering wheel is clocked correctly relative to the pitman arm? I want to use a 2x4 across the doors to hold the steering wheel straight when the mechanic does the final tie-rod end adjustment.
• What is a good front height setting? I know the spec is 2" ±1/8" side to side. Right now, the bottom of the adjusting blades are about 1/2" higher than that the bottoms of the ball joints. Measuring down from the bottom of the adjusting blades to the floor, I have them set at 8-13/16" with P195/75R14 tires @ 35 psi. My '75 FSM has this measurement at 10-15/16".

IIRC from previous attempts at getting my alignment right, getting negative camber (-0.25° L&R) and positive caster (+1.25°L & +1.75°R) becomes harder as the car gains height. It appeared to be only possible with the springs adjusted down the LCA bumpers and the strut rod bushings overtorqued. The tops of the tires are about level (±1/2") with the wheel opening lip so the car has a slight rake. From earlier handling and aero discussions, it looks like there is advantage to lowering the front end but the tie-rod sleeves should be level to minimize any bump-steer issues.

For the most part, the only cornering I do with this car is on the highway on & off ramps. I've installed a set of Addco bars (1-1/8" Front & 3/4" rear) years ago but I don't have any plans yet to upgrade the stock torsion bars. Any advice would be greatly appreciated.

Just saw this post,, Looks like you have a handle on what you are doing.
I'll try to answer some of your questions,
1 The alignment shop should have a steering wheel holder when setting the toe.
2 Pitman arm only goes on 1 way as it has 3 locater notches in the splines that align with the sector shaft splines. You will notice if you have wrong as it will be way off.
3 You said you have the previous alignment specs.So you have a starting point,,this is done Before removing the old cams settings.Look at their location,maybe draw a diagram, hold the offset bushings and do a visual 'clock'of where the bushings need to be to gain the wanted adjustments.You will want to install the offset bushings to give you the cam setting you desire.
This is about as clear as I can make it without standing next to you and the car.
Yes, make the car stance as low as possible and still be able to get it into the specs you want. Lots of trial and error. The biggest thing is getting the offset bushings in right the first time.

That's good to know as I didn't see them (either of the 2 shops I've used) using one when they do the final wheel centering adjustment.
It looked to me that there is only one way to put the pitman arm on the steering shaft. However, I am not confident that the pitman arm is centered (parallel to the car's centerline) when the steering wheel is centered. If the arm and steering wheel aren't clocked correctly, the shop will use the tie rods sleeves to center the steering wheel, thereby putting the pitman arm off center.

When I originally put everything together, I turned each sleeve out exactly the same number of times (so that the ends would each be exactly the same length) when I did my rough toe adjustment in my garage. IIRC, my steering wheel was not centered afterwards.
I was just going to install the offset bushings in the orientation explained in this posting.
I can see that there is a trade-off between lowering the center of gravity and ensuring that the car doesn't keep bottoming out. This probably also something to do with how fast you drive and how rough are your roads.

I don't have an air dam under my car so the frontal area of the car will change very little with changes in ride height. Lowering the car might reduce the airflow under the car, thereby causing more of it to flow over the much smoother top of it. I'm not sure if this actually happens in practice.

From Doc's earlier comment about bumpsteer, I think it makes sense to adjust the height so that that the tie-rod sleeves are level. Once you decide on a tire diameter, it easier to get the alignment mechanic to use a previously determined measurement from the adjusting blade to the ground.

_________________
1965 Plymouth Barracuda,
225 engine, Quadrajet, HEI, Dutra Duals, 904 Torqueflite, 2.76:1 axle, Addco front bar
Rods & Relics - Fort Erie, ON / Collector Car Tech

Yes that's good on installing the off set bushings,again to acheve the alignment specs you want.Back to the pitman arm, any good alignment shop should know that the steering gear has what is known as "high point".With the pittman off or disconnected from the centerlink,rotate the wheel completely to the left to get a starting point, count the number of turns to to the right till you reach the stop,lets say, 3 1/2, turns, rotate back to the left just about 1 3/4 turns and you should feel resistance, pass that point the resistance goes away, got back right again to the resistance. That is your "high point" the center of the steering gear.Your pitman arm should be relatively straight when installing it on the spline notches.Now the alignment rack,if it is correctly calibrated should get the toe into spec with the tie rod adjusting sleeves.
Again the height,"stance" whatever you wish is up to you. I've seen guys set them against the bumpers on the lower control arms,some even shave the bumper down to give more travel.NOT saying that this is correct but will allow more suspension travel. AGAIN saying if you want the ride height lower than stock but still allowing the alignment to be in your specs.
You talked about bump steer,yes you want the tie rods to be relatively as straight as possible, again juggling all the variables to get the adjustments into spec. Now I will throw a monkey wrench into this and say that I've seen 2'' drop spindles installed that set a 2'' angle(or more) on the inner to outer tie rods and driving the car normal you will never know the difference.Now spirited or extreme driving it would come into play. Again sometimes you bend the rules a bit for the "Look".Also giving thought on how you intend to drive the car.
I've worked with big named car builders that knew how to acheve the "Look" but were way off on function. Everyone does things a bit different sometimes to reach the end goal. Just a thought.

It should be possible to get your desired specs with stock bushings, and quite easy with the MOOG offset bushings, at about any ride ht.

Romeo is right on with his responses, as you would expect!

I would set ride ht around 1-1.5" lower than stock, reading between the lines on your post, do the alignment there, then adjust ride ht to taste from there.

Best handling will come with no rear sway bar, but some people like the feel of the rear bar.

Lou

_________________
Home of Slant6-powered fun machines since 1988

So far, I've been to an alignment shop several times since the slider disc brake upgrade:

1. Originally, I went to a nearby tire shop, which has an alignment machine. I wasn't happy with result (car riding almost on the LCA bumpers) and I wasn't thrilled about paying to train the mechanic on a-body peculiarities
2. A club member recommended a shop in nearby city that specializes in alignments (even has alignment in its name). They couldn't get the car alignment to the "granny" specs but the car drove well enough afterwards.
3. After the car developed alignment issues, I went back to the alignment shop that diagnosed the problem as loose rear strut rod nut and a worn right ball joint. I couldn't believe ball joint could wear out in less than 4000 miles 'and I lost some confidence in the shop's abilities. After double-checking for myself, the (Just Suspensions) ball joint was in fact very worn and I replaced it with a Moog ball joint.
4. There was another local shop that claimed to have a knowledgeable mopar alignment mechanic so I decided to give them a try. However, the appointment was on a Friday but they bumped me for another in-house job (I obviously neglected to reconfirm that I was actually coming for my appointment). Since I had a tour scheduled for the Saturday morning, I ended up going back to shop #1 because they could squeeze me in for 4 pm that day. I ended up with a major RH pull and subsequent shoulder wear this summer as I've been waiting for Just Suspensions to come through with a ball joint credit that I wanted to apply to a new pitman arm.

When I took the car to shop #2 (with "alignment" in its name), I ended up with -2.6°L & -2.15°R caster and +0.10°L & +0.32°R camber with the concentric urethane UCA bushings. This was with very over-torqued strut rod bushings. Having read the service manual more carefully, I torqued the strut-rod bushing nuts to 40 ft-lbs after replacing the ball joint, which probably made it more difficult to get positive caster for the next alignment back at shop #1.

I notice that the wheels have major negative camber as the front wheels hang down when up on blocks. That seems counter-intuitive to what I saw while the alignment guys were trying to get my target negative camber and positive caster. So ... I haven't found that it is possible to get negative camber and positive caster with the concentric bushings at a useable height. Is it possible that I have this backward and it is actually easier to get negative camber & positive caster with more height?

Thanks for the explanation of steering gear's high point. I read up on the steering gear section of my service manual and but it's still not clear to me what causes the resistance to increase at the high point. It looks like the high spot is manufactured into the gears to mark the center of mechanism.

In any case, with the pitman arm disconnected from the center link, it looks like I can use tape to mark the center of the steering mechanism on the column. The center of the steering wheel should stop at equal points on each side of the column. If it doesn't, I'll have to re-index the steering wheel. With luck, this should correspond to the high spot in the steering gear.

I just checked my tie-rod sleeves and both of the inboard sides are about 1/4" higher than the outboard sides. If the lower control arms and their tie-rods are about the same lengths (which they appear to be), shouldn't bump steer be negligible for any height if the steering wheel is correctly indexed relative to the pitman arm? OTOH, if the wheel is improperly indexed, then the tie-rods should be unequal in length after the steering wheel is centered, thereby causing bump steer.

_________________
1965 Plymouth Barracuda,
225 engine, Quadrajet, HEI, Dutra Duals, 904 Torqueflite, 2.76:1 axle, Addco front bar
Rods & Relics - Fort Erie, ON / Collector Car Tech

Yes high point is machined into the sector gear.
Yes as the front rises the camber should go negitive. Caster should stay relatively the same.(On some of my friends drag cars we actually jack the car to simulate the front rise as it is going down the track while making adjustments)
Yes bump steer should be negligible with all items listed.

Now next time you go to the alignment shop and they give you a computer print out, look for a "toe out on turns" spec. If not,, see if they give you a deer in the headlights look when you ask for it. It is something seldome ever checked.This is where your wheel indexing may come into play along with other factors.But don't stress over it.

After having the car up on blocks for the past year, I've finally got offset bushings installed in my upper control arms. The forward bushings point outward while the rearward bushings point inward to give me more positive caster and negative camber. I've disconnected the outer tie-rod ends from the lower ball joints but have left the pitman and idler arms attached to the center link.

I'll use the center spoke of my rally steering wheel as my reference so that straight ahead is 6:00.

Turning the steering wheel from one extreme to another, I see that that the steering wheel appears to be at around 10:00 while turned all the way to the left (CCW) and about 5:00 when turned all the way to the right (CW). This works out to about 5-5/8 turns, lock to lock.

If I understand correctly what was written earlier, there should be exactly the same number to turns from center, left to right when the steering wheel is clocked correctly.

_________________
1965 Plymouth Barracuda,
225 engine, Quadrajet, HEI, Dutra Duals, 904 Torqueflite, 2.76:1 axle, Addco front bar
Rods & Relics - Fort Erie, ON / Collector Car Tech

Yes, make sure to clock the wheel in the center of box travel so you have the "tight spot" of the gear mesh on center when the st wheel is straight. This tight spot may be worn out on an old box, but was designed in to aid feel when going straight.

Lou

_________________
Home of Slant6-powered fun machines since 1988

Larger torsion bars will allow lower ride height without bottoming on bumpers. Bottoming seriously effects braking. I think maybe you are giving bump steer too much priority in your thinking. Camber and caster, toe in, and ride height, are higher on my list. I have had about 5 different suspensions on this car, and have never been at all aware if tie rod sleeves were level, and have never been aware of bump steer at all. If I got it "right" it was purely accidental.

I am one of those guys Lou mentioned who is willing to sacrifice autocross handling for the feel with the rear sway bar. To be honest, when I had the super stiff, six pack springs on the rear, the rear sway bar created nervouse, twitchy, uncertain oversteer. I find the rear bar and the current soft 4 pack rear springs ideal for my taste. The rear sway bar gave this particular set up a positive on center road feel that was missing before. While it does not handle as well, or ride as smooth as my BMW 328, it "drives" as nice.

Every car is its own unique entity. This is not one size fits all. No magic formula can predict how it will turn out. I have played with this car for 23 years now, and am currently very happy with the suspension set up. It started with 13" SBP wheels, soft springs everwhere, no sway bars, 9" drum brakes and was a nightmare on the road. It has been many "different" cars over the years. The one thing I can tell you is that changes often improved things, but sometimes not exactly as I thought they would. The reason for going into this is to let you know while all the careful planing is nice, be prepared to thoughtfully analyze the result and plan future changes based on what you feel from the car. Enjoy the game and the process. My next change: after all this, I thing I am going back to rubber bushings in the shackles. See; one is never really finished.
Sam

_________________

Thanks for the advice. I am still using the original slant six front bars and a local spring shop set me up with new 5-leaf rear springs many years ago. I find that, with the Addco 1-1/8" front bar (PN 751) and 3/4" rear bar (PN 919), my car has an oversteer tendency.

I was planning to remove the rear bar but maybe I would be better off removing a leaf. I thought that having positive caster (aiming for +1.5°) would give me on-center road feel.

As for bump steer, this isn't something that I've noticed happening but I also don't push the car very hard either. I just think that the car would drive better with the steering wheel properly clocked, which would allow for L&R tie-rods that are more equal in length.

_________________
1965 Plymouth Barracuda,
225 engine, Quadrajet, HEI, Dutra Duals, 904 Torqueflite, 2.76:1 axle, Addco front bar
Rods & Relics - Fort Erie, ON / Collector Car Tech

My caster is set at 4. I do think the heavy rear springs and sway bar are too stiff and create overstear. It took tubular aftermarket UCA to acheive 4 degrees caster. I could push it to 9 if I wanted to. IBefore I installed the rear sway bar I intended to set it at 6 with the next alignment for more road feel, and better on center feel, but the sway bar supplied what I was looking for,and likely will not change it now.

Lower caster reduces stearing effort. I suspect higher castor numbers translate into slightly higher tread wear in cornering, but it would be very slight if at all.

Sam

_________________

You can tune the anti-roll bars by playing with the bushings.


Replacing rubber with poly effectively increases the size of the bar and poly with rubber will make the bar seem smaller.

_________________
Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Good thought Ed. The same thing is true of the end links. There are various styes and hardnesses. I am pretty sure you can get end links with heim joints that offer no flex at all. My Miata was set up that way from the Factory.

Frank, what car are you working with here? In spite of everything I said about being open and flexible, there are some things everyone does that work well, generally. The biggest issues are wheel size and offset, tire size, spring rates, alignment specs and finally, sway bars, and sizes. There seems to be an almost endless combination of these factors. When you take it to the alignment shop again be sure to have a 4 wheel slignment done so you can make sure the car is square. If it is not, you can shim the rear spring mount box on one side or the other.

One more qualifying comment, Lou, (Dart270) drives his cars all out competitively, while I just want mine to handle like a modern car. That would explain any differences in our approaches. We do not disagree in basic cause and effect of changes.


Sam

_________________

The car I'm working with is the one described in my signature. The rims are the basic 14x4½ that came with my 74 Duster parts car. The tires are an old set of economy Motomaster AW+ P195/75R14. I was thinking about upgrading to P215/60R15 later on.

I think that I'm more with you than with Lou on handling A reasonably soft ride with better cornering ability is fine with me.. I was quite happy with how well my basic 73 Dart with a 1" front bar (Addco PN 186) would handle.

The alignment shops here normally do 4-wheel alignments and one recent alignment showed that had the following final results:

Rear Camber: -0.29°L / -0.34°R
Rear Toe: 0.13"L / -0.07"R / 0.05" Total
Rear Thrust Angle: 0.05"

There were slight differences between initial and final results at the rear.

_________________
1965 Plymouth Barracuda,
225 engine, Quadrajet, HEI, Dutra Duals, 904 Torqueflite, 2.76:1 axle, Addco front bar
Rods & Relics - Fort Erie, ON / Collector Car Tech