Spring Plate Bushing Replacement: 68 912 Coupe
By Troy Berreth
It sounds so easy! Not that it isn't (in theory), but I was also lowering the car...
Tools required: This is the 'biggie' - I started off with not the correct ones, and it probably cost me a couple of days of sweating and cursing... The two that immediately come to mind is a large, flat pry bar. I bought mine from Sears and it was only $10 or so (green one about 16 inches long and 2 inches wide or so). Taking off the bushings at first, I used a big screwdriver - it was terrible. Another tool is a magnetic protractor (also bought at Sears for $10) to measure the angle of the spring plate when you (a) first take all the bolts off of you current suspension setup (measure the angle when the arm is hanging free), and (b) when you are re-installing the torsion bar. This is critital if you want to get both sides the same and to also get both sides to be at the correct height. I wanted to lower my car, which caused me a ton of grief as well. I didn't have the pry bar for the 1st coupld of times I took off and put on the plates, in addition to not having the protractor. With both of those, it was 'fairly' easy.
If I had the 'right' tools from the beginning, it would have made it MUCH easier, but I didn't and understood that fully in the end.
You're right in that you have to remove all bolts including the shock bolt to relieve tension. The tricks. When you have loosed all the bolts on the radius arm and taken the shock bolt off, it will hang free. Scribe a line on the body so you can have a reference point. Getting the spring-plate off (bushing cover plate as well as the spring-plate (radius arm)) off was another issue. What really worked in the end was a big, flat breaker bar from Sears. I didn't have this the first few times I did it, and had to remove things with a large screwdriver and a lot of pounding/twisting/bending...
Once you get the assembly off, you have to get everything free of each other, which is another 'pain'. When you remove the radius arm from the torsion tube, the torsion bar 'may' also come out with it (attached to the radius arm), or stay back inside the torsion tube - you want it to stay inside if you're not lowering the car. Then comes the part of removing the bushings themselves - well, they are vulcanized to the radius arm and I now know the 'trick'. Taking the bushings off the radius arm (spring plate - different words for the same thing), I used a screwdriver, big knife and pounded and scraped them - or at least tried to. 35 years of galvanized rubber was almost impossible to get off. What I tried was to get a torch, but apparently didn't get it hot enough. Trick #2 is to put a torch on the inside of the tube the bushings ride on and get that thing SO hot that they slide off. Like I mentioned, it was very difficult for me - probably took another 1.5-2 days just to get them off and cleaned up. I had to peel them off with a screwdriver/hammer and knife, but heard that you can get a torch and heat up the inside of the metal tube really hot and they will eventually 'burn' or slide off... it took me MANY, many hours to get this done and wish I knew about the extreme heat before. I did try a torch, but apparently didn't get the metal hot enough.
When I got the old bushings off and the arm all cleaned up, I had big trouble getting the new bushings on. Do you have the poly (plastic) bushings? If you do, did you get the grease? If not, then they DEFINITELY will squeak. WIth the poly, they probably will squeak. I went with the Neatrix ones though (between the OEM and plastic) as I had to with my year of car (the ones I originally ordered for a 68 didn't fit), so i'm not sure how easy yours will go on. They sqeak a tiny, tiny bit. I didn't use any lubricant as Gabe at Strasse (where I bought them) said there have been recent discoveries on the Neatrix ones when you use grease - it's supposed to drastically shorten their life-span. Putting the new bushings on. Found out that the easiest for me was to put both bushings on the spring plate, THEN put the whole assembly back on the car. Mine were EXTREMELY tight, and I had to lean against the wall (back to the wall) and push with both feet as hard as I could (after lubing the bushings up with soapy-water). Of course, I didn't try this right away and it took me the better part of the day to get the 1st one on. After doing this 4 or 5 times, I finally got the hang of it. The reason why I had to do it so many times is that I couldn't get the ride height set correctly. Too low, then too high, then too low... bought the protractor and thought I was smart and set both sides to the same angle, was quite surprised when the one side was higher than the other.I found the best was was to attach the outer bushing first, and then put the torsion tube cover on that, then slide the inner bushing on, then put the whole assembly on the car - of course, mine wouldn't go on the car even with the help with a lot of soapy water and pounding... eventually, I used the wall of my garage as a back support and pushed with both feet and slowly got them on.
Most of my troubles came about as I wanted to lower the car. I had to take the plates off 4 or 5 times to get it right as the splines on the inner and outer end of the torsion tubes are different and equate to different ride height. Like I said before, IF you don't want to lower your car, and IF your torsion bars didn't come out of the torsion tube, and IF you scribed a line while everything was hanging free, then you SHOULD be able to put the radius arm back on at the same angle - if the bar came out of the inner tube, then all bets are off! Getting the angle right was also aided a lot by buying a $10 protractor at Sears which has a magnetic edge and let me measure the angle out to 28 degrees (giving approximately 25" ride height at the rear). Of course, my passenger side had to be different and had to be 31 degrees for some reason... I eyeballed it at first, but after a few attempts and getting the height wrong, I bought the protractor.
When you get the car back on the ground, pushing up and down doesn't settle it enough, and you'll have to drive it around the block to make sure. Of course, you can't tell what the height will be, even after lowering it to the ground, until you take the car for a drive...needless to say, I spent a LOT of time fooling around with it. I noticed a big difference in handling and no more squeaking...