All models use a recirculating ball steering box with a Pitman arm at the steering box, relay rod connected to the Pitman arm, idler arm attaching the relay rod to the subframe, and two tie-rod ends connecting each end of the reley rod to the steering knuckles.
Power steering and a tilt column are options.
The various boxes have different ratios, most notably in the Cosworth Vega and V8 Monza.
David (monzaaddict) adds:
"The quick ratio box has an input shaft about three inches long as opposed
to one inch for the Vega manual box. The last three digits of the numbers
on the box are 142. Box was also (first) used on V8 manual steering Monzas
and then the Cosworth Vega. Box directly replaces power steering box with
square cover (not box with round cover that came on some Monzas). Pitman arm
is supposedly same as found on power steering box."
Get the box, steering shaft, Pitman arm, and steering center link from a car with the kind of steering you want. Those parts are all different and not interchangeable for power vs. non-power steering. See question 4.14 for tips on how to create a custom steering shaft from donor parts.
MOOG part numbers:
Flaming River sells new Vega-style manual boxes.
Special notes for going to power (V8): the alternator must be moved (new brackets belts, lengthen wiring harness) to the other side of the engine to make room for the larger power box.
After 1979, GM used a larger diameter input shaft on power steering units, so beware of this as you look for parts!
Tom (TheAstre) writes:
"Be careful not to mix apples and oranges. Last Summer, I swapped out the
standard steering in my 75 Astre for power steering out of my old 76 Astre.
Both were 4-cyl. But I can tell you this... Lots of little things had to
change. The standard Vega Manual Gearbox is much shorter and smaller than
the Power Steering Gearbox. The Steering column had to be changed because
the steering shaft is different depending on which steering box is used.
Also changed was the pitman arm and the center link, because the center link
had a different part number. It mated up and looked OK, but I thought it
hung a little too low. Also, I had to move the Alternator from the driver
side to the passenger side. This required a different mounting bracket,
which required changing the timing belt cover, due to a small difference.
Now that the Alternator had to move, I had to change the wire harness, as
the other one was too short to reach the new position of the alternator.
No big deal for cutting and hacking, but to get everything to look stock,
lots of tiny things had to be swapped. I have heard that the Cosworth
manual steering box is larger than the standard Vega manual steering box.
I heard that it is the same as the Monza V-8 manual box. I don't know for
sure, but can check for you. So if you are swapping Monza gearboxes, there
may be other considerations."
Then he adds: "If you decide to change to a manual gearbox, make sure to get all the other pieces you will need. The manual gearbox is a few inches shorter, so you will need to switch the steering column rod. Some years are different, so it is easier to just switch the entire steering column, steering wheel and all. The pitman arm is different, but that usually comes with used steering boxes. The center link offset is different where it bolts to the pitman arm. It will bolt up and be drivable. But your steering wheel will be offset. You could just index the steering wheel on the column post, but this leads to other problems. The turn signals will be off by [the same offset]. Worst of all, the centering dynamics of the steering box and linkage will be off by that same [offset]. The natural balance of a centered gearbox will be distorted. This will be more noticeable and critical to handling at high speeds. Even Moog lists the manual and power center links as different part numbers. If you get parts to swap. Pull them yourself. Mark the alignment of every piece with a grease crayon. Some parts only fit in one position, but others will leave you wondering if you have it lined up right. So, take the column, gearbox, pitman arm, spacer between gearbox and frame, center link, and idler arm."
Later Tom wrote: "The Vega Manual gearbox is much smaller/shorter than the Vega/Monza Power gearbox. You will need a Manual steering column to make up the length difference. Or, use a manual gearbox from a Monza or Cosworth Vega. I have heard that they are the same length as the power gearbox. Last year, I switched my Astre from manual to power and learned of all the differences.
Three BIG things to consider: 1) On standard Vega and Cosworth, the manual
gearbox uses a shim between the frame and the gearbox. Without this, your
gearbox will not internally center properly.
2) The Pitman arms are different. Use the Pitman arm that is correct
for the gearbox.
3) The center link is different. The point the connects to the Pitman
arm is about 1-1/2 inches different in length. If you don't switch the center
link, your steering gearbox will be internally off center. Your steering wheel
will be about 1/4 turn to one side. You could re-align the steering wheel on the
column shaft, but the gearbox will still be off center internally.
Without all the correct pieces, the steering geometry will be off. The car will tend to turn easier to one side than the other. Not bad for around the city, but at highway speeds it is far more noticeable.
If you did Monza to Monza, everything is the same size. Only the Vega Manual Gearbox is smaller and shorter than the others. The steering column shaft is at least 2 inches different in length. There is no way one could "make it fit". The Vega manual center link is different where it connects to the Pitman arm. The end is 1-1/2 longer and sets at a different height. For a Vega to Vega conversion, this will cause the center link to either rub on the oil pan, if you go power to manual, or rub on the K-frames if you go manual to power. Mine did, till I changed the center link."
Kevin (SoloII_74) explains why to be careful when mixing-and-matching parts:
"I can say with certainity that the 1/2" longer steering arm will affect the turning
radius, and steering quickness (a fair amount slower). The whole steering mechanism (pitman arm,
center link, etc.) will be forced to move through a significantly longer arc because of this additional 1/2"
in steering arm length. The steering box internal stops will most likely not allow the the rest of the
steering to hit those external stops.
I had a similar problem with a small block/old mercedes swap I performed. I switched the steering to a GM rack & pinion, but the rack & pinion was a slower internal ratio, and was intended to be used with a much shorter steering arm length, and thus I could not get enough steering travel. The turning radius went from about 30' (original steering) to well over 50'(new steering). I had a set of the steering arms shortened (on the mercedes they were bolt on forgings, not a grey iron casting), and this corrected the problem. The turning radius ended up being slightly less than 30', and the steering response was much quicker."
Larry (vega_man_larry) writes about the steering shaft:
"One thing I learned from Dave at Dave's Vega Village is that the
different shaft lengths can be
manipulated to get what you need in a column or steering gear box swap.
I have a manual steering car
that I transplanted a tilt column into. I took the manual collumn shaft
and the tilt column short shaft and
combined them. The columns are hollow and have a teliscoping feature.
You heat the shafts up with a
propane torch and slide them apart. You then take the top and bottom
halves that you want to keep and
combine them. I relocated two of the alignment holes, and injected nylon
hot glue from my wife's glue
gun back into the column to fasten it back together, thus restoring the
collapsing feature. You could
probably do the same for a power steering to manual steering or vice
versa. All you really need is the
shaft pieces. It makes it easier than finding the appropriate pieces
which can be hard to find especially in
the case of a manual to tilt column swap as most tilt columns came in
power cars."
Duke (doctorduke) adds, about Pitman arms:
"All the couplings you refer to are keyed, so they should only go
together in one orientation. There are THREE
H-body pitman arms. The CV uses the same pitman arm as V-6 and V-8
H-bodies with manual steering. All
H-bodies with P/S use a second pitman arm. The third pitman arm is used
on 140s w/o PS. Make sure you have the
correct pitman arm."
Assuming you have the parts from a Monza with the torque arm setup:
For the lower control arms and Panhard rod, Myles (mylesgt) says:
"The Monza lower control arms bolt up. What I usually did was just leave
the whole lower assembly alone (Monza), also keeping the larger sway bar.
Then welded Vega upper link supports onto rear. Bolted it up. Fits great,
no bad vibrations. Panhard rod's top plate bolts into another support plate
that's part of the later bodies. [You] would have to fabricate/weld the
upper part of the rod to accomodate it into the earlier Vegas.
A couple of members have in fact added it to their earlier 4-link, and
apparently it does work."
For the torque arm, you will need the arm itself, the rear axle housing from the donor car, and you'll need to find a way to mount the arm onto the tailshaft of the transmission (grab parts from a torque arm car with your drivetrain) OR you can fabricate a mount that is welded to the body.
Ken Mahoy (mahoy78spyder) explains how to mount a torque arm:
"I did something similar to my very first Monza, a 75 Town Coupe, that I
swapped in a TH350 short shaft from a
1970 Chevy van. Since I didn't have the Monza TH350 tailshaft w/ the
accomodations for the torque arm mount, I
had to shorten my torque arm with a plasma cutter and then weld on an
"L" bracket down the new front of the arm.
The bottom of the L-bracket bolted to the tranny crossmember directly
and worked very well - especially since I was
16 at the time and launched hard every chance I got!"
Paul (pvgatto) adds: "There's been a lot of discussion lately about springs. Most people refer to "V8 springs," "V6 springs," or "4 cyl springs." Unfortunately this is not exactly correct. One day I did some research at my local parts store to try to determine the RIGHT springs to use for my application.
According to the Moog catalog, there were no less than six different springs used on various H-Bodies. I have personally tried two of these. I found the #5576 to be WAY too stiff. The #6490 is what I'm currently using, but I still cut 1.5 coils to get my car "in the weeds."
I have included the part number, the application, the spring rate, and the load rating.
Here's the list:
Denis (denisst78) compiled a list of all H-Body springs including their applications and specifications:
Coil Spring Applications and Specs
FRONT Coil Spring Applications
==============================
With A/C W/O A/C
1980 monza
4 cyl hatchback coupe and sport coupe cs-6490 cs-5622
4 cyl notchback coupe cs-6490 cs-6490
6 cyl Hatchback ¬chback coupe cs-5622 cs-5624
6 cyl Hatchback Sport coupe cs-5624 cs-5624
1979 monza
4 cyl 2+2 hatchback Sport coupe cs-6490 cs-5622
4 cyl hatchback & notchback coupe cs-6490
4 cyl station wagon cs-6488 cs-6490
6 cyl hatchback & hatch sport coupe cs-5622 cs-5624
6 cyl nothcback coupe cs-5622 cs-5624
8 cyl hatchback & notchback coupe cs-5624 cs-5626
8 cyl hatchback sport coupe cs-5626 cs-5576
1978 monza
4 cyl hatchback "S" coupe cs-6490 cs-6490
4 cyl hatchback coupe & sport coupe cs-6490 cs-5622
4 cyl nothback coupe cs-6490 cs-6490
4 cyl station wagon cs-6490 cs-6490
6 cyl 3.2 hatchback & notchback coupe cs-5622 cs-5624
6 cyl 3.2 notchback coupe cs-5622 cs-5622
6 cyl 3.8 hatchback "S" coupe cs-6490 cs-5622
6 cyl 3.8 station wagon cs-6490 cs-5622
8 cyl (ALL) cs-5626 cs-5576
1977 vega
ALL cs-6488 cs-6490
1977 & 1976 monza
4 cyl 2+2 hatchback coupe cs-6490 cs-5622
4 cyl notchback Towne coupe cs-6490 cs-6490
8 cyl ALL cs-5626 cs-5576
1976 & 1975 vega
ALL cs-6488 cs-6490
1975 monza
ALL cs-6490
1974 vega
ALL (exc. station wagon) cs-6434
station wagon
1973 vega
All cs-6434 cs-6434
1972 vega
All cs-6434
1971 vega
All
REAR Coil Spring Applications
==============================
All years and models
CS-6377 (constant rate)
CS-617 (Variable rate)
Coil Spring Specifications
==========================
P/N wire diam. installed installed installed spring free
in inch height load(lbs) rate (Lbs/inch) height
Front Coils
CS-5576 0.625 9 1814 384.5 13.690
CS-5622 0.590 9 1555 308.0 14.152
CS-5624 0.590 9 1640 309.0 14.430
CS-5626 0.590 9 1740 309.0 14.728
CS-6434 0.593 9 1306 373.2 12.520
CS-6488 0.590 9 1359 330.1 13.130
CS-6490 0.590 9 1465 317.9 13.630
Rear Coils
CS-6377 0.504 10.25 484 141.1 13.690
CC-617 0.565 10.25 475 156.0 13.310
4.5 What stock swaybars came with H-bodies?
Front:
PST sells most bushings in a kit.
TRW, Federal Mogul, and MOOG make replacement pieces:
Springs:
Vega front:
CS6488 or CS6434 with no A/C, CS6490 with A/C
(note: 6488 is probably for the wagon)
Vega rear:
CS6377 regular, CS617 variable rate
Monza front:
Engine Bodystyle No A/C With A/C
-------- ----------- ------- --------
4 cyl hatchback CS6490 CS5622
4 cyl wagon CS6488 CS6490
6 cyl hatchback CS5622 CS5624
6 cyl notchback CS5622 CS5624
8 cyl hatchback CS5624 CS5626
8 cyl notchback CS5624 CS5626
8 cyl Spyder CS5626 CS5576
Monza rear:
CS6377 regular, CS617 variable rate
Steering:
K6196 Idler arm
ES425RL Outer tie rod end (need 2)
ES681N Inner tie rod end (need 2)
ES2032S Adjusting sleeves (need 2)
DS816 Center link, 71-76 manual steering, 77-78 4 cyl manual steering
DS889 Center link, 71-76 power steering, 77-78 4 cyl power steering,
80-77 all 6 & 8 cyl [also Cosworth?]
Front Suspension:
K6118 Upper ball joint (need 2)
K6157 Lower ball joint (1975-1980) (need 2)
K6119 Lower ball joint (1971-1974) (need 2)
K6112 Upper control arm bushing kit (OEM-style) (need 2)
K6155 Upper control arm bushing kit (offset) (need 2)
K6113 Lower control arm bushing kit (need 2)
K6158 Lower control arm shaft kit (need 2)
K5241 Sway bar bushing (15/16 and smaller)
K5253 Sway bar bushing (1" and bigger)
Rear Suspension:
Vega (pre-1976):
K6114 Upper control arm (need 2)
K6115 Lower control arm (need 2)
Monza and 1976-up Vega:
K6166 Torque arm
K6115 Lower control arm (need 2)
K6180 Track bar (aka Panhard rod)
K5241 Sway bar bushing (15/16 and smaller)
K5253 Sway bar bushing (1" and bigger)
Note for Panhard rod: If you can't find Monza pieces, use bushings for a 3rd-gen ('82-'92) Camaro Panhard rod.
Pot Joint Boot: Rob (MonzaRob) discovered that the boot for the pot joint is the same as one from a 1986 Jeep CJ, which is much easier to find than one for an H-body.
4.7 What are some aftermarket suspension pieces?
3-3140 rear for pre-1976 Vega
3-3141 rear for 1976-up Vega and all Monza
3126 front end
9-8117 swaybar endlinks (made of urethane)
885 front 1 inch
710 front 1 1/8 inch
984 rear 7/8 inch
672 rear 1 inch
They also have offered a 1 1/4" front bar to CVOA members
at one time but may not produce these bars regularly.
Clyde (CJBIAGI) offers this advice:
"It's important to realize that there is not a lot of travel on the front
suspension of H-Bodies. My 75 monza
(when it was stock) used to top out on a regular basis. I wasn't exactly
sure what the problem was initially
but as I later came to find out later when I removed the front shocks,
they were almost fully extended at
normal ride height. Basically the car just sat too high. What I have
learned now is that the front shocks have
4 inches of total travel, so what this means is when you install them
you should have to compress them 2
inches to put them right in the middle of their travel range. If they
are not in the middle of their range they
are more likely to top out or bottom out, depending on where they end up
when installed. In my case it was
the shocks that actually top out before any other suspension part. So
you need to take whatever actions are
necessary to put the shocks in the middle of their range, adjusting ride
heght, putting a spacer on the shock
and making sure you have the right shocks. The Bilsteins I used to have
had less than 4 inches of travel
compared to the Monroes I have on now. It's very easy to see where your
shocks are in there range, just
loosen the 2 bottom bolts and see how far it comes down from the control
arm, like I said it should be 2
inches. A very small amount of difference makes has a big effect, even
if it is only off by 1/2 inch that
means you only have 1 1/2" of travel in the opposite direction. It's
also important not to confuse shock
travel with wheel travel, because of the length of the control arms and
the fact that the shocks are located
closer to the pivot points there is less shock travel than wheel travel,
but the important thing is that the
shocks are in the middle of their range.
Kevin (SoloII_74) offers his sway bar experience:
"You should use the larger bar -with a caveat! (to come).
The Cosworth bar is 1", and the Monza bar most likely is not 1 3/16", but maybe 1 1/8", as the largest aftermarket bar for H bodies is 1 1/4", with 1 1/8" being the most common aftermarket size.
Here is the caveat --> You will need to find a matching 7/8" rear bar to keep a good front/rear roll stiffness balance. If you cannot find that larger rear bar, go with a set of Cosworth sway bars (I know you should have a spare set).
A few years ago, while experimenting with my (then) new +++ sized Addco sway bars (a special purchase from Addco through CVOA), I made the mistake of installing the 1" Addco rear bar with my 1 1/8" V8 monza spyder front bar. The car went from being very neutral, to totally out of balance as I had increased the rear roll stiffness way out of proportion with the front. The car was oversteering very badly (to use a Winston Cup term, it was "loose", "very loose").
Upon entering a sharp corner, the front would bite, and the rear would slide. It was almost like having a spike driven through the oil pan into the ground, so the car would pivot around, using the front wheels as the rotating axis. Oh, the car was a bear to drive that way! Well, next event, I installed the front bar, and the neutral handling was back, albiet at a higher level.
If you install a much larger front bar without a matching rear bar, you will experience more understeer ("push") than you would with a balanced suspension set-up. You will maintain the same roll stiffness balance as long as you install the matching Monza (or use a Cosworth set) rear bar.
As a side note, US manufacturers in general, and GM in particular tended to design a fair amount of understeer into all of their cars because the average driver does not know what to do with any amount of oversteer, and feels more comfortable with a car that steers like a pig into corners."
Britt (kiva75) adds: "I too run the Addco 1 1/4" front and 1" on the rear. I agree that this maintains the cars neutrality, while still allowing throttle oversteer. You can get the bars any time, but be prepared to wait. It took Addco over six months to send my bars, and then they were the wrong ones. My friend had better luck, it only took four to get his. They are relocating thier operations right now and told my brother (who works at an Addco retailer) that they had no company to cad plate the bars, so delivery time right now is unknown. He ordered his bars and it's been seven months.
Just a word of warning. I will also agree that they would be a lot better if hollow, because the front bar weighs aroumd 35-40 pounds.
You may want to try upgrading to hard urethane or aluminum bushings with the stock bar, that might help too."
4.8 What is a good drag racing suspension setup?Not too much here for specifics, but basic ideas:
Not too much here for specifics, but basic ideas:
Kevin (SoloII_74) offers this advice:
"I autocrossed my '74 for 3 years as an H stock Solo II car. No
modifications outside those
allowed by the stock class rules - no urethane, etc., just stock rubber
bushings. I still ripped
the upper rear control arm mounts out of the body. I had them welded,
and they held up ok.
(I have switched to the later torque arm type suspension, so I cut out
the (now) un-needed
mounts.) I also have since had to re-weld some of the body welds. The
stress of going
around corners was just too much, and I have found a number of cracks in
some of the
stressed areas (both front and rear).
Most of the people I know who have autocrossed an H body seriously (and sucessfully) end up adding or re-doing some welds to reinforce the stock spot welds. These welds were never intended to handle the high stresses which the current generation of "gumball" autocross tires can place on the chassis and suspension.
4.10 How do I add a front swaybar to a car that never had one?If your H-body never had a front swaybar, then you likely do not have the front lower A-arms that have brackets on which to mount the swaybar endlinks. So one option is to find lower front A-arms that have mounts for the swaybar endlinks, the get the swaybar and endlinks themselves--it will all bolt up.
One complication is that the lower front A-arms on Vegas do not have the same depth spring pocket as the Monza/Sunbird/Skyhawk/Starfire. The pocket is shallower and using a Monza arm on a Vega will lower the front end assuming you don't change the springs. So, one other option for the Vega (thanks to Tim (TimMcCabe99)) is to attach an endlink (cut roughly in half) to a spherical rod end to create a Heim joint. Then drill a hole in the lower A-arm and mount the eye of this joint through that hole.
Tim adds: I have found that using a locknut (nylon type) on the outside of the 3/8 bolt that goes through the lower control arm and heim joint is a good idea, I had the nut fall off a couple of times, even with a lock washer.
Denis (denisst78) gives more details about the conversion:
"Get the frame brackets from a donor car or
from a part store (be sure to measure which size
of sway bar you got).
Get one end link kit (rubber grommets and acc.)
Get two 3/8 rod ends (heim joints)
Get two 3/8 bolts (not sure of length)
Get six 3/8 nuts
Get two 3/8 bolts (1 1/2 inch long)
Mount the bar to the car with the frame brackets
center it for the end links; when the bar is tightened on the frame
make sure part of the bar that's bolting to the a-arm is level (front to rear).
Slip in this order: bolt, washer, rubber, bar, rubber, washer, sleeve.
Now tighten everything tight with the extra 3/8 nut.
Install the rod end.
Mark the location where to drill the a-arm.
Drill the hole.
Install in this order: 1 1/2 long bolt, rod end, 3/8 nut, a-arm, nut.
Tighten everything.
BTW It's a good idea to weld a piece of 1/8 thick plate or washer to the back side of the a-arm. It will make the area where you drilled a whole lot sturdier.
4.11 How do I add a rear swaybar to a car that never had one?The rear swaybar attaches to the rear lower control arms through two bolts on each arm. Even cars that never had rear swaybars have control arms with these holes. So, you need these parts, which should all just bolt on:
This is a tough one. The steering rack would need to be where the relay rod now sits. If the rack were located anywhere else, the steering wouldn't work correctly due to the acute angles of the arms coming out of either end of the rack.
However, if the rack is in that position (where the relay rod is now), the steering shaft won't be able to connect to the steering input on the rack, because the driver's side inner fender (and upper control arm) would be in the way. This happens because the rack's input would be around 6" lower and 6" closer to the front of the car compared to the input on the stock steering box.
One possible solution is to mount the rack where the relay rod is now, then make a custom steering shaft that comes out of the firewall, over the driver's side headers, then into a U-joint, then almost straight down into the rack's input. [NOTE: I have no expertise in this area, but this seems unsafe!]
If you are willing to install a roll cage and new front subframe, you can get rack & pinion steering. See question 6.19.
Aleck (stinkybuttihave) says:
"Just dug out my Don Hardy catalog and they list a cross member
that welds in and is used to mount a Pinto rack. The part #08-066.
The crossmember also requires two clamps #08-069. They list all kinds
of chassis parts as well as headers. My cataloge is about five years
old so I'm not sure how many things they still sell."
Later he adds:
"I'm not sure what you consider a kit but Don Hardy sells a weld in
crossmember to mount a Pinto rack and pinion in a Vega. Parts:
# 08-066 Weld in crossmember 1 1/4" tube
# 08-069 Rack +Pinion clamps
# 08-072 Flex shaft 12"
# 08-073 Adapter for shaft to R+P
The "right" thing to do is have a competent body shop get the frame back into specification.
The "cheap" thing to do is use new A-arm bushings. Moog and probably other places make upper A-arm bushings that have more adjustability in them than the stock pieces so that you can compensate.
If you have this problem due to sagging, Roger (ks_skyhawk) also recommends: "While you are down there, look at the area around the base of the spring towers, the outside 90 degree bend (on the ends of the part parallel to the engine) near where the control arm bolts are. Look for hairline cracks in this area. I found them on mine. I stopdrilled the top end of the crack and welded."
Tim (TimMcCabe99) explains one way to adjust the frame:
"You can pull the lower frame rails back in line by attaching a chain to the idler arm and attaching the other
end to the pitman arm on the steering box. By cranking the steering to the right it will pull the rails back
together.
After this is done, the "K" member should be boxed to add strength, and the bolt holes should have
washers welded to them to eliminate the oval boly holes. When the boxed "K" member is reinstalled, the
negative camber caused by the lower control arms speading should be corrected.
I had my "K" member removed to fix my oil pan after it had bottomed out on the highway. After about a
week of being up on ramps, I could not get the crossmember back in. I used the chain trick to pull
everything back in line and it worked great."
The columns interchange, but you'll need the right coupling for the steering box, and the ignition switch must be rotated 180 degrees.
Larry (vega_man_larry) adds:
"Any tilt column will work. Just make sure you get the column coupler shaft that connects to the steering
gear box. The tilts I have found are on power steering cars. If you don't have power steering (I don't)
you have to make a coupler from the upper part from a tilt column and the lower from the standard
steering shaft. Heat up the shaft using a propane torch to melt the nylon that holds the shaft together
where the shafts slip together for the collapsing feature. Then put the two parts you want back together.
I drilled two new holes to line up with the inner shaft and cemented it back together using my wife's glue
gun (basically replacing the nylon. Don't weld the column back together as you will be defeating the
collapsing feature!"
For 1976-up cars:
The panhard rod bolts to a bracket that is then bolted to the body
near the driver's side wheel well. Using shims between this bracket
and the body, the side-to-side positioning of the rear end can be changed.
Another option is to bend the panhard rod, but that will weaken it and
is not recommended.
For pre-1976 cars that came with a bent panhard rod: bending is an acceptable way of adjusting it, per Chevrolet Tech Bulletin #75-T-14 Number IV. Use chains on each end of the bar, and force in the middle, to bend the rod. DO NOT USE HEAT. The brackets may have been welded incorrectly to the body on some cars and this bending is to compensate.
The panhard rod should be kept level when the suspension is at rest. That is, the rod should be the same distance above the axle tube on each side. If the car is raised or lowered, the bracket for the bar should be relocated to compensate.
Tim (cosworth_twincams) adds:
"On some of the early 75's Cosworth's and Monza's the panhard rod was not
correctly bent so there was
a problem with tire rub on the left (drivers) rear tire. GM put out a
rear wheel spacer kit which included a
wheel spacer and longer lug bolts."
Swapping the arms side-to-side greatly increases the caster angle.
Mike (mich_southpaw) writes:
"More caster makes the car go straighter
with more effort to steer. The car is more stable, because the steering
doesn't react quite as quickly due to the extra caster. Have you ever
looked at a dragster and noticed how much the top of the kingpin is
behind the bottom? The tires actually flop from side to side when steering
from lock to lock. This is a good thing for going fast on the strip.
100 extra caster would probably work on the street but may cause other
handling problems. The offset bushings are the route I would go if the
car sees street driving."
Randy (monzamiler) reposted information from Tom (???): "You can swap the upper control arms side to side and get about 9.5 degrees of caster. A small amount of grinding needs to be done. I have done this to my '78 Monza that I run at Bonneville. I also cut two coils and use Moog upper offset bushings to restore the camber (the car is stable to well over 200 mph)."
4.17 What are some alignment specs?Factory recommendation for a 1977 (posted by Nick):
Warranty | For inspection | Specs 4 resetting
Caster -1.8 to +.2 | -2.8 to +1.2 | -.8 +/-.5
Camber -.6 to +1.0 | -1.3 to +1.7 | +.2 +/-.5
Toe in(degrees) -.19 to +.06 | -.42 to +.31 | -.06 +/-.06
4.18 Are Cosworth and Monza steering boxes the same?
Ken (mahoy78spyder) writes:
"The reason John Thawley (the guy who wrote "Building the V6 Vega")
mentioned using a Cosworth unit
box is that they are beefier, yes, but I thought I would add that they
are no different than a "Monza"
manual steering box. So a Cosworth one, or a Monza (or clone) one should
suffice. Also, the RPO N44
Fast Steering Ratio was a planned option for the Cosworth, but was
cancelled prior to production. The
Cosworth was produced with the standard Vega steering ratio, but used a
larger, heavier steering gear
housing from the Monza V-8. The fast ratio steering gear was eventually
offered over the counter and is
listed in the fourth and fifth edition Chevrolet Power manuals.
(thanks to Duke Williams for part of that information)"
Marco (Monzabudd) explains:
"Today I found out that not all V8 Monza power steering pump pulleys are the same. there is a 5 1/2" unit
and a 6 1/4" inch unit, both factory. The smaller came on V8 No-Air cars and the bigger from V8s with
Air. And as you probably know the bigger pulley will turn the pump slower resulting in less drag on the
engine at all speeds, and possibly even helping take some of the lightness from the factory power steering
on cars without air cond."
Robert (twelve_second_vega) suggests:
"Here is my method. I don't think you can do much to re-enforce the upper
control arm mounting areas, so I ease the
strain by making the Motion Upper Traction Links instead. Take a bushing
and locate a section of tubular steel that it
will press into. Weld a section of steel tubing about 4" long onto this
tube and add a piece of channel at the top that
will attach the the upper control arm. I don't have a good picture of
one, but I found it in the "V8 Vega Handbook". I
also add the Torque Arm to the stock Vega 4-Link Rear Suspension."
Robert (twelve_second_vega) says:
"As with many modifications, most people go too far. If you are not
racing the car exclusively, you will be better off
using a milder approach. I begin by boxing all the control arms, upper
and lower for added strength. On the upper
arms, I form a piece of 3/8" round steel stock around the outer lip of
the arm and stitch weld it in place. One reason
I feel this is necessary is the amount of material removed to facilitate
the installation of the S-10 Upper Ball Joints. I
add the Torque Arm to the early Vega 4-Link Rear Suspension with Moog
"Cargo Coil" Variable Rate Springs to
minimize "Squat" under acceleration. I use the lightest rear sway bar I
can find, usually from a 4 cylinder Vega GT. I
prefer Oversteer to Understeer and too much rear roll rate can make the
car a bear to drive. I use 1-1/16" diameter
front sway bars (from V6 Sunbirds) and Sunbird V6 Front Springs. For
shocks, I use a conventional hydraulic type.
Not gas charged. I don't like the dampening of a gas charged shock,
other than Koni or KYB. However, these
performance shocks are a waste of money on a street driven car. When set
up in this fashion, the car displays very
neutral handling charactaristics and good suspension movement under
acceleration. For all out racing, you would
probably want things different, but for the street, this is a hard
combination to beat."
First, you need to drop the lower control arm from the spindle so you can remove the old spring. Jack up the car, remove the wheel, remove the shock, then put a hydraulic jack under the lower control arm, leaving an inch-or-so gap under the arm. The car should be about 1 foot off the ground at the LCA mounting points, and the jack should be somewhat extended.
Remove the nut and cotter pin from the lower ball joint, then separate LCA ball joint from the spindle. When you do, the spring will force the LCA down with a couple hundred pounds of force (be careful). Then use the jack to slowly lower the LCA down. Next, remove the jack and push the LCA down as far as it will go, then pull out the spring.
To get the new spring in, the idea is to use a threaded rod with fingers or a plate on the end of it. The rod is inserted through the upper shock mount hole and the fingers or plate grab near the bottom of the spring (but not the very bottom as the spring eventually will need to sit in the lower control arm). As the rod is turned, it draws the spring up into the upper spring pocket.
OTC makes a tool just for this, but it's expensive. You can do the same with a regular internal spring compressor--Autozone loans them for free. The compressor comes with a long, sturdy threaded rod and upper and lower "fingers." One set of fingers "floats" and the other threads onto the rod. You won't need the "floating" fingers.
Put the new spring up into the upper spring pocket. Disassemble the tool and push the rod through the upper shock mount hole--be sure to use a washer or two. Position the "threaded" fingers on the 2nd or 3rd coil from the bottom, then thread the rod into them. Finally, turn the rod until the spring is compressed enough. The fingers will want to rotate and make the spring curve in undesirable ways, so you need to help guide it. When it's compressed enough you can just swing the LCA up and reattach it to the spindle.
Brian (Bacchus_101573) writes about a similar method:
"Using a 3 foot section of 5/8" threaded rod and some Gr8 nuts and washer, I passed the
rod through the upper shock mount, through the spring, through the lower control arm, and
through a piece of 1/4" steel that I had lying around. The steel is about 6"x6", enough to
fully support the lower A-arm. 5/8" is almost exactly the size of the upper shock mount
hole, so it fit very well.
I snugged up the nuts a ways (not too far) and then used a floor jack to raise the rear of the lower control arm to put the bolts in first. I think a bottle jack would work better because you can concentrate the force more. Then I compressed the whole thing until I could get the spindle attached. And that's about all it takes! Of course, it took me 4 hours to do this because of some trial and error. I anticipate that I'll be able to do the other side tomorrow in about 1.5 hours. The hardest part is getting the lower control arm holes lined up to put the bolts in."