Also Need Figs. 29 and 30


Where I live, on the north coast of Ohio, salt and winter conspire to ravage cars. This dynamic duo causes some of the most frustrating and difficult of restoration problems, especially when you get deeply into a project, such as Ken’s 1976 Cosworth Twin Cam.

He had been driving it while away at Purdue, and spent most of his "at home" time visiting Kristin. It wasn't until his graduation, wedding and subsequent honeymoon that I got the chance to drive it for the first time in years. I immediately noticed that the front end bounced--a lot.

A hearty shove downward on each front fender quickly told me the shocks were shot. I knew I had a project, but concluded it would be a small one. Just an hour or so, I thought. It just needs new shocks.


When I crawled under the car, however, I quickly saw that the driver's side shock had broken away a large piece of the lower control arm. My quick project had suddenly assumed sizeable proportions. I considered doing some overhead welding, but quickly banished the thought. While I can weld under perfect conditions, overhead is tough with an AC stick welder. Besides, I just knew that the camber adjusting bolts, which pass through the frame, control arm bushing, and back through the frame, were frozen in place by corrosion. This would be a great opportunity to free them and allow the front end to be aligned. So I crawled under, confident that with a stout breaker bar and a can of spinach, I would have no trouble.

I considered doing some overhead welding, but quickly banished the thought. While I can weld under perfect conditions, overhead is tough with an AC stick welder. Besides, I just knew that the camber adjusting bolts, which pass through the frame, control arm bushing, and back through the frame, were frozen in place by corrosion. This would be a great opportunity to free them and allow the front end to be aligned. So I crawled under, confident that with a stout breaker bar and a can of spinach, I would have no trouble.



Fig. 1

I first tried to remove the nuts on the camber adjusting bolts with a stout breaker bar. No luck. So I resorted to the hot wrench.    (Fig. 1 )


Then I tried the breaker bar on the heads of the camber bolts. But, as I expected, they too would not budge. Not with the breaker bar. Not even with a cheater pipe over the breaker bar. It seemed that what I needed was a really long cheater pipe, but I knew from experience that I would merely break the bond between the rubber in the bushing and the inner sleeve, and that the bolts still would not come out. There had to be a better way.

I knew that a hot wrench would work, but that I would have to destroy the bushings and likely the camber adjusting bolts as well. I also knew that it was not a "green" solution. Acrid clouds of dense black smoke from burning rubber are no longer acceptable, and I hesitated to temper the surrounding metal or to incinerate any remaining corrosion fighting primer that might remain in hard to reach areas of the frame. So I promptly rejected that idea.

I then considered using the Sears reciprocating saw Barb had given me for Christmas one year. Armed with cutting oil and a handful of Milwaukee8 bi-metal 24tpi Sawzall8 blades, l examined the situation carefully. Given the lack of clearance caused by the U-shaped adjusting plate, I could not simply cut the head from the bolt. Plainly I had to cut through the bushing itself between the ears of the control arm.

I began. It was all I could do to make progress. Cutting through the outer case of the control arm bushing was easy. But once I moved into the rubber it was an entirely different story. The rubber from the bushing squeezed the blade tightly, generating copious amounts of heat from the friction, forcing me to pull the saw from the kerf constantly to allow the blade to cool. In desperation I had to make a second cut to form a "V" to get down to the inner sleeve that gripped the bolt so tightly.

Once there the job became even more difficult. The bolts are hardened. My arms quickly became tired pressing down on the saw as the blade simply seemed to ride on the shank of the bolt, hardly phasing it. There had to be a better way. Though hack-sawing was plainly not the answer, I persevered anyway and after more than an hour, successfully severed the bolt. Woe was me, however, as it still refused to come out. I had to repeat the process toward the other end of the bolt, finally allowing a center section about an inch wide to drop out.

I was then able to drive the threaded end of the bolt inward enough to bend it down and pull it out. But the "head" end of the bolt still would not come out. Looking carefully I could see that the inner sleeve remained tightly welded by rust to the stub of the bolt shank, and that until it was removed, the bolt could not pass through the hole in the frame. Fortunately using a drift and a BFH allowed me to break it free and drive it out. Tired, sweating, hair full of dirt and rust, I concluded that there had to be a better way.

I began to examine the pieces that I had removed, and that’s when I saw the solution.

The inner sleeve is not a piece of seamless tubing, as it first appeared. 

Rather, it is a rectangle of mild steel rolled into a tube but not welded. A seam runs the length of this tube. A few raps of a heavy hammer on a chisel centered in the seam quickly peeled it away from the threaded end of the bolt, breaking the rust-weld....

Obviously if I could chisel the sleeve away from the shank while the control arm was still on the car, I could free the bolts without risking a visit from the EPA or the fire department, or without spending a morning and a fortune in Sawzall blades trying to saw them free. 

I decided to try my theory on the other side of Ken's Cosworth, and it worked. 


Here’s the procedure I developed.


First, jack the front of the car high in the air and support it with sturdy jack stands


This provides the safety and clearance necessary to work from below.

Next, remove the front tire and wheel, compress the suspension using a jack placed under the lower ball joint, remove the shock absorber, and using a pickle fork, separate the lower ball joint from the spindle.

As a safety measure, wrap a chain or stout cable through the coil spring, secure it to the frame, then lower the jack slowly.

If the spring does not fly out, as mine did not, remove the chain or cable and pry out the spring with a large crowbar.


Now the fun begins. Don a good pair of goggles and slide under the car. A large sheet of cardboard on the floor makes this so much easier, and makes cleanup a breeze too. Grab your air hammer (you did bring it with you, didn't you), fitted with a freshly sharpened wide chisel bit, or a hammer and selection of sharp chisels.

Fig. 2

 Using the corner of the chisel, poke a hole in the outer metal case of the control arm bushing close to one ear of the control arm. (Fig. 2 )

Fig. 3

Be careful not to let the chisel jump and cut into the control arm itself. Once you pierce the casing, angle the chisel to extend the cut in both directions, leaving you with a slot. (Fig. 3 )


Move to the opposite end of the bushing and repeat the process. (Fig. 4).

Fig. 4

This will leave you with parallel cuts approximately 1-1/4 inches long.

Now turn the chisel perpendicular to the cuts, place it at one end or the other, spit the rust and dirt out of your mouth, shake it out of your ears and hair, and squeeze the trigger on the air chisel yet again to sever one end of the casing between the slots. 

Fig. 5


You should now have a "U" shaped cut, (Fig.5.), and if you deftly insert the chisel under the flap you have created.........

........ you can pry back a curved rectangle of the casing, exposing the rubber of the bushing underneath. (Fig. 6.)

Fig. 6


Fig. 7



Fig. 7A

At this point you need to cut out the exposed rectangle of rubber. Use the chisel on all four sides of the rectangular opening and cut all the way to the inner sleeve. (Figs. 7 and 7A). 


Fig. 8



Fig. 8A

Upon the completion of your last cut, the rubber "plug" should simply fall out, exposing the sleeve. (Figs. 8 and 8A)

Before you try this, however, re-sharpen the chisel. If it is even the least bit dull, it will simply bounce around rather than cut.


If the day you have chosen for this project is your lucky day..... .
.... the seam in the sleeve will now be visible. (Fig 9)

Fig. 9

A very few rare Cosworths were manufactured with sleeves containing seams fabricated on a bias. (Fig. 9A.)


A "Bloomington Gold" level 100 point restoration will require diligent searching for lower control arm bushings with the properly fabricated inner sleeves, so pay particular attention to whether or not your seams are straight!


Since removal of the rubber plug exposes only about 30% of the sleeve, the odds are only 3 in 10 that this will be your lucky day.

Fig. 10

 If it is an unlucky day, (Fig. 10), simply put the breaker bar with a short cheater pipe on the head of the camber bolt and pull or push, whichever is more convenient (neither will be easy).



You may be able to turn the sleeve inside what is left of the rubber bushing, thereby exposing the seam. If not, more chisel work is needed. Try and separate the rubber from the sleeve in both directions and pull or push on the breaker bar again. Sometimes it will turn. If not, grab a long cheater pipe. When the cheater pipe is long enough, the bolt/sleeve will turn.

When the camber bolt/sleeve finally does turn, keep turning until the seam appears and presents a good angle for the chisel. Insert the air chisel blade into the seam and pull the trigger again. Move back and forth along the seam, peeling the sleeve away on both sides. (Fig. 11)

Fig. 11


Then try to turn the bolt again. If you have peeled back enough of the sleeve, the bolt will turn, grudgingly at first, and then more easily, as the rust crumbles and drops into your hair and onto the cardboard.

Fig. 12

Work the bolt back and forth to grind away as much rust as possible, and tap/hammer out the bolt. (Fig. 12.)


Repeat the entire process for the other bushing, remove the control arm and take it to your workbench. Don't forget your air hammer and the wide chisel.
If the bolt doesn't turn, however, and on northern cars it probably won't, don't despair. Simply crawl out from under the car and sharpen your narrow chisel.


Go back underneath, turn the sleeve to put the seam to one side of the opening, then chisel two cuts perpendicular to the bolt/sleeve (Fig 12A),.......


.......and follow that with a lengthwise cut in the sleeve, making your own longitudinal seam. Since the sleeve is mild steel and you are using a sharp narrow chisel, the sleeve will cut easily.
 (You may need to re-sharpen the chisel frequently since it will quickly dull when it hits the shank of the hardened bolt)

Next, angle the chisel into the seam you have just created and peel it back in both directions. Watch out for the rust that will sift down as you chisel back the sleeve.


You may be tempted to squirt some CRC 5-56(TM)or WD-40(TM) or some other rust penetrant / lubricant at this point to ease your work, but refrain. The rust will crumble and fall out more readily if it is dry; your goal is to create as much clearance as possible. Put your cheater-ed breaker bar on the head of the bolt and again try to work it back and forth. If it moves even the tiniest bit, it can be worked loose. All it will take is time and muscle. Be patient and persistent.

Unfortunately, even though you may eventually break the bolt loose from the sleeve, it will sometimes remain frozen to the two concave washers (called ferrules) that protect the ends of the bushings. (Fig. 13)

Fig. 13

They have collars that grip the bolt shank snugly, and they tend to seize to the shank. (Fig. 14. )




Since they are wedged between each end of the bushing and the frame, it is impossible to chisel them loose. Heat will work, of course, but as there is quite a bit of rubber still in place, driving the bolt out makes more sense. There is only one problem. The ends of the bolts are fairly inaccessible, and even if you have jacked the car up fairly high, it is extremely difficult to swing a heavy enough hammer forcefully enough while lying on your back to be effective. So let your air chisel ease the task for you.

The trick here is to screw on the rusted nut that you heated cherry red to remove way back when you first started. Screw it most of the way on the exposed threads, leaving a shallow depression before the end of the bolt. Then mount the pointed bit or the hammer bit in your air chisel, insert the pointed end or hammer end in the shallow depression you have created, and pull the trigger. Even though you will be aiming at about a 45 o angle, with max air pressure in your compressor tank, the bolt will begin its retreat in short order. Remove the nut and tap the bolt the rest of the way out with a drift and hammer, working the head with the socket on your breaker bar when it binds. Once both bolts are out, take a deep breath, remove the lower control arm and head for your big bench vise.



Fig. 15

While it may be possible to press out the entire bushing at this point, I don’t have a press, so I must to take a step-by-step approach. You can too. First, chisel the inner sleeve closed. Then, using a socket on the pitching end and a short length of 1 ¾" id pipe on the catching end, press the sleeve out of the bushing with your vise. 
(Fig. 15)

Check your progress as you work. (Fig. 16)

Fig. 16

Usually the rubber of the bushing will come out along with the sleeve (Fig. 17),....

Fig. 17

Fig. 18



...... though it will sometimes require the assistance of a bit of gentle persuasion from a BFH and a suitable drift. Once out, you will plainly see how your efforts opened up the inner sleeve. (Fig. 18)


At this point only the metal case of the bushing remains to be removed. (Fig. 19).

Fig. 19

To do this, carefully use the air chisel to force the narrow end of the casing inward about half an inch at one point, being careful not to nick the control arm. Fig. 20.


This should remove about twenty percent of the casing from contact with the control arm


Fig. 2

Then, insert your thin, wide, curved blade chisel between the flange of the flange of the casing and the outside of the control arm (Fig. 22), throttle back the air pressure, and carefully force it under the flange.

Work it around the perimeter to wedge the flange away from the control arm. (Fig. 23.)

Fig. 23

Turn the control arm on end and tap the casing the rest of the way out. (Fig. 24. )

Fig. 24

Here’s the final result. (Fig. 25).

Fig. 25

To complete the project, drive out the old ball joint, sandblast the control arm (after taping off the inner edges of the holes), paint with your favorite paint (I use POR-15® and swear by it), install the new bushings (MOOG K6113) (Fig. 26), and finish with a new ball joint (MOOG K6157).

Fig. 26


Installing the new bushings is fairly easy, even without a press. They are an interference fit, so freezing the bushings (use dry ice if possible--its colder) and baking the control arm in the kitchen oven can make this job almost a slip in. Just make sure that you install each bushing in the proper location. On the Cosworth, the front and rear bushings are different: The rear bushing is soft to give the suspension some fore/aft compliance to reduce bump harshness, while the stiffer front bushing takes most of the lateral cornering load. 


This is the same design philosophy used on the new C-5 Corvette!

The GM Part numbers from Duke Williams’ 1979 parts book are # 378117 front; # 3988062 rear, but they may no longer be available. MOOG, undoubtedly as the result of inventory consolidation for an old vehicle, did away with the different bushings; their kits use the same durometer bushings front and rear.

Be sure to install the bushings first. If you bake the control arm with the ball joint installed, the smell of hot grease and burning rubber will insure that you never ever will be able to use the kitchen for your Cosworth again. Indeed, you may finally have to break out the Hatch-Hutch and spend the next few days and nights in the garage sleeping in your Cosworth in the company of only your tools—not even the dog will join you.


You won't be a happy as Jake and Cindy.

Alternatively, simply cold soak the bushings in your refrigerator's freezer section and press them in with your large bench vise. A couple of tricks will be necessary here, however. First, coat the inside of the control arm ears with Mobil 18 or another fully synthetic oil. It does a better job or reducing friction than regular oil or grease. Second, make a pair of "C" shaped inserts from a section of pipe to place between the two ears of the control arm to prevent the outer ear from bending inward as you begin to press.

To do this, saw a 2.45" length from a piece of 3" pipe, then cut that piece in half lengthwise, so that you have two "C" shaped sections.  (Fig. 27.)
 Slip them between the two ears and hold them together with a wrap or two of tape. (Fig. 28).
Next, take an old bearing race and place it on the bottom of the inner ear to provide a flat purchase for the vise (Fig. 29),.......
...... insert the frozen bushing by hand, and place another old bearing race on the flange of the bushing to provide purchase and ultimately clearance during installation. (Fig. 30).


Crank down on your vise (it will turn much more easily if you have also lubricated the screw with synthetic oil or grease) and the bushing will press in place as nice as you please.


That's all there is to it. Install the new ball joint, screw in the Zerk fitting, tap the washers in place on the ends of the bushing, slather the new camber adjusting bolt shanks (MOOG #K6158) with Never Seeze®, and reinstall. Your Cosworth and your front end alignment professional will thank you.