The 1955 Chevrolet Shop manual has a procedure for rear spring removal. I followed that procedure on one side of my 1956 Canadian Pontiac (which has chassis identical to the Chevrolet for 1956) and it worked OK, but did not help me with removal of the right rear shackle the spare tire well interfered with pulling it straight out. (The fuel filler hose interfered with the left rear shackle but there was enough flex in the hose that the shackle came out OK.)
With ideas from others, I figured out how to remove the right rear shackle. And after doing one side following the shop manual, I figured out a better way to do the whole procedure given below.
1. Jack the rear of the car up high enough so you can work under the rear spring. Support the car on jack stands.
2. The U-bolts protrude downward and will have 50+ years of crud on them. Wire brushing will help but will not do an adequate job. Use a rethreading die to chase the 7/16-fine threads. This will make removal of the nuts MUCH easier. (The nuts on the shackles and the front spring-eye through-bolt do not have much protruding so chasing the few threads that show isnt necessary.)
3. Liberally apply PB Blaster to all of the nuts under the car (one lower shock mount, 4 U-bolt, 2 shackle, one front spring-eye through-bolt).
4. Remove shock absorber. The shop manual procedure works fine. However if you cant keep the shaft from turning while trying to remove the upper nut, heres one way that works. You will need two people to remove the upper nut one under the car with a large vise-grip to hold the shock and keep it from rotating, and one in the trunk to remove the nut. Let the shock collapse away from the trunk floor.
5. Use your ½ drive air impact wrench (all the bolts and nuts you will be removing under the car have been there 50+ years and need plenty of torque to take them apart a powerful air impact wrench ensures theyll come apart with a minimum of fuss, much better than regular hand tools) with a ¾ socket to remove the lower nut; clean it and the washer and lock washer, and set them aside for installing the new shock later.
6. Use your ½ drive air impact wrench with a ¾ deep socket to remove the 4 U-bolt nuts. Clean up the lower spring plate and set it aside for installing the new spring and shock later. If you do not plan on using new U-bolts, clean them and their nuts too.
7. Put your jack under the rear axle, near the differential, on the side you are working on. Jack up the rear axle just enough so it is a little bit above the spring. Put a jack stand under the axle. Put your jack under the spring, just in front of the rear axle, and raise it so it is just touching the spring but not pushing upwards. (This will help in removing the front spring-eye through-bolt by ensuring there is no force pulling or pushing on the spring-eye.)
8. From under the car, looking towards the outside of the car, use a trouble light and look through the access hole in the frame to see the head of the front spring-eye through-bolt. You will have to crane your neck to see it. There will probably be 50+ years of dirt inside the frame, partially obscuring clean access to the bolt head. Use a small brush, or pick, or whatever tool to clean around the bolt head so you can get a nice grip with a ¾ six-point socket. Use a drive deep socket with a 3 extension and your drive ratchet to carefully snake your way through the access hole and get a good grip on the bolt head from inside the frame. Use your ½ drive air impact wrench with a ¾ flex socket to remove the nut on the outside of the frame it helps to have 2 people for this but you can do it alone. Do NOT remove the ratchet from the bolt head!!! Holding the ratchet to keep the bolt from dropping inside the frame, gently pound the bolt through the spring-eye and through the frame. (A 5-6 long drive extension works great for this even better if you cut the square head off the male end I made one and it comes in very handy for many jobs.) Keep the bolt captive inside the deep socket, and once it clears the frame, gently remove it using the socket with extension (you can be more gentle if you remove the ratchet from the extension-and-socket). Clean up the bolt and nut and set them aside for installing the new spring later.
9. Let the jack slowly allow the spring to fall downward. You might need to wiggle it a little bit, or apply a little downward pressure at the spring-eye, but usually itll come right out. Remove the jack and let the front of the spring rest on the ground.
10. Use your ½ drive air impact wrench with a ¾ socket to remove the shackle nuts. Remove the outer plate. Pull the spring end outward to remove it from the shackle. Set the spring aside, out of the way. (Doing the rear shackle last avoids the need to drive the shackle out of the spring using the shop manual procedure; this way is much easier.)
11. Rotate shackle upward so it is parallel to the frame rail and pound the bolt through the spring hanger. (That drive extension used in step 8 works perfectly here too.) On the drivers side, it should come out without problems. On the passengers side, if you dont have a station wagon, it will hit the spare tire well read the following but dont try to do anything until step 12. If you are not installing new shackles, clean up the shackle parts and set them aside for installing the new spring later. After all this, you are going to install new bushings, right? Remove the old bushings from the shackle hanger. Theyve been in there 50+ years and will not just slide out. Use whatever method works for you to remove the old bushings. I use a variety of chisels and picks to get most of the outer bushing out, and pound the inner bushing out (after dousing it inside and out with PB Blaster) using a suitable deep impact socket (its outside diameter must closely match the bushings). If you have a station wagon, youre done.
12. That darn tire well! If only it was another ½ inch or so away from the frame! Well you could cut out the tire well and some guys will want to do this so they can have a flat floor in the whole trunk. If you are one of them, nows the time to cut that tire well out, and the shackle will come out easily as in step 11 above. Otherwise, with the shackle parallel to the frame rail and the shackle bolt pounded through until the shackle hits the tire well, remove the outer bushing as in step 11. Then push the shackle back into the inner bushing and pound the inner bushing out (after dousing it inside and out with PB Blaster) using a suitable diameter deep impact socket (the deep socket will allow the shackle bolt to remain mostly inside the bushing). The end result is that the shackle, with the inner bushing on it close to the shackle plate, will tilt enough to come free (the hole in the hanger is much bigger than the shackle bolt, but only if the bushing is away from the hanger).
Here are some pictures that illustrate:
13. Reverse the above procedure to reinstall everything. Put the upper inner bushing on the shackle before inserting it into the hanger, then the outer bushing, then put the spring with its bushings on the shackle, then the shackle plate and nuts, etc.
I hope you find this tweaked procedure helpful, I did find it works better than the shop manual pocedure (and solves the problem of the tire well interference on the right side without major surgery, just changing the sequence of steps).
Dave
-- Edited by davelacourse at 15:38, 2009-02-19
-- Edited by davelacourse at 08:31, 2009-02-20
-- Edited by davelacourse on Monday 16th of March 2009 05:23:45 PM
The 1955 Chevrolet Shop manual has a procedure for rear spring removal. I followed that procedure on one side of my 1956 Canadian Pontiac (which has chassis identical to the Chevrolet for 1956) and it worked OK, but did not help me with removal of the right rear shackle the spare tire well interfered with pulling it straight out. (The fuel filler hose interfered with the left rear shackle but there was enough flex in the hose that the shackle came out OK.)
With ideas from others, I figured out how to remove the right rear shackle. And after doing one side following the shop manual, I figured out a better way to do the whole procedure given below.
1. Jack the rear of the car up high enough so you can work under the rear spring. Support the car on jack stands.
2. The U-bolts protrude downward and will have 50+ years of crud on them. Wire brushing will help but will not do an adequate job. Use a rethreading die to chase the 7/16-fine threads. This will make removal of the nuts MUCH easier. (The nuts on the shackles and the front spring-eye through-bolt do not have much protruding so chasing the few threads that show isnt necessary.)
3. Liberally apply PB Blaster to all of the nuts under the car (one lower shock mount, 4 U-bolt, 2 shackle, one front spring-eye through-bolt).
4. Remove shock absorber. The shop manual procedure works fine. However if you cant keep the shaft from turning while trying to remove the upper nut, heres one way that works. You will need two people to remove the upper nut one under the car with a large vise-grip to hold the shock and keep it from rotating, and one in the trunk to remove the nut. Let the shock collapse away from the trunk floor.
5. Use your ½ drive air impact wrench (all the bolts and nuts you will be removing under the car have been there 50+ years and need plenty of torque to take them apart a powerful air impact wrench ensures theyll come apart with a minimum of fuss, much better than regular hand tools) with a ¾ socket to remove the lower nut; clean it and the washer and lock washer, and set them aside for installing the new shock later.
6. Use your ½ drive air impact wrench with a ¾ deep socket to remove the 4 U-bolt nuts. Clean up the lower spring plate and set it aside for installing the new spring and shock later. If you do not plan on using new U-bolts, clean them and their nuts too.
7. Put your jack under the rear axle, near the differential, on the side you are working on. Jack up the rear axle just enough so it is a little bit above the spring. Put a jack stand under the axle. Put your jack under the spring, just in front of the rear axle, and raise it so it is just touching the spring but not pushing upwards. (This will help in removing the front spring-eye through-bolt by ensuring there is no force pulling or pushing on the spring-eye.)
8. From under the car, looking towards the outside of the car, use a trouble light and look through the access hole in the frame to see the head of the front spring-eye through-bolt. You will have to crane your neck to see it. There will probably be 50+ years of dirt inside the frame, partially obscuring clean access to the bolt head. Use a small brush, or pick, or whatever tool to clean around the bolt head so you can get a nice grip with a ¾ six-point socket. Use a drive deep socket with a 3 extension and your drive ratchet to carefully snake your way through the access hole and get a good grip on the bolt head from inside the frame. Use your ½ drive air impact wrench with a ¾ flex socket to remove the nut on the outside of the frame it helps to have 2 people for this but you can do it alone. Do NOT remove the ratchet from the bolt head!!! Holding the ratchet to keep the bolt from dropping inside the frame, gently pound the bolt through the spring-eye and through the frame. (A 5-6 long drive extension works great for this even better if you cut the square head off the male end I made one and it comes in very handy for many jobs.) Keep the bolt captive inside the deep socket, and once it clears the frame, gently remove it using the socket with extension (you can be more gentle if you remove the ratchet from the extension-and-socket). Clean up the bolt and nut and set them aside for installing the new spring later.
9. Let the jack slowly allow the spring to fall downward. You might need to wiggle it a little bit, or apply a little downward pressure at the spring-eye, but usually itll come right out. Remove the jack and let the front of the spring rest on the ground.
10. Use your ½ drive air impact wrench with a ¾ socket to remove the shackle nuts. Remove the outer plate. Pull the spring end outward to remove it from the shackle. Set the spring aside, out of the way. (Doing the rear shackle last avoids the need to drive the shackle out of the spring using the shop manual procedure; this way is much easier.)
11. Rotate shackle upward so it is parallel to the frame rail and pound the bolt through the spring hanger. (That drive extension used in step 8 works perfectly here too.) On the drivers side, it should come out without problems. On the passengers side, if you dont have a station wagon, it will hit the spare tire well read the following but dont try to do anything until step 12. If you are not installing new shackles, clean up the shackle parts and set them aside for installing the new spring later. After all this, you are going to install new bushings, right? Remove the old bushings from the shackle hanger. Theyve been in there 50+ years and will not just slide out. Use whatever method works for you to remove the old bushings. I use a variety of chisels and picks to get most of the outer bushing out, and pound the inner bushing out (after dousing it inside and out with PB Blaster) using a suitable deep impact socket (its outside diameter must closely match the bushings). If you have a station wagon, youre done.
Here are some pictures that illustrate:12. That darn tire well! If only it was another ½ inch or so away from the frame! Well you could cut out the tire well and some guys will want to do this so they can have a flat floor in the whole trunk. If you are one of them, nows the time to cut that tire well out, and the shackle will come out easily as in step 11 above. Otherwise, with the shackle parallel to the frame rail and the shackle bolt pounded through until the shackle hits the tire well, remove the outer bushing as in step 11. Then push the shackle back into the inner bushing and pound the inner bushing out (after dousing it inside and out with PB Blaster) using a suitable diameter deep impact socket (the deep socket will allow the shackle bolt to remain mostly inside the bushing). The end result is that the shackle, with the inner bushing on it close to the shackle plate, will tilt enough to come free (the hole in the hanger is much bigger than the shackle bolt, but only if the bushing is away from the hanger).
13. Reverse the above procedure to reinstall everything. Put the upper inner bushing on the shackle before inserting it into the hanger, then the outer bushing, then put the spring with its bushings on the shackle, then the shackle plate and nuts, etc.
I hope you find this tweaked procedure helpful, I did find it works better than the shop manual pocedure (and solves the problem of the tire well interference on the right side without major surgery, just changing the sequence of steps).
Dave
-- Edited by davelacourse at 15:38, 2009-02-19
-- Edited by davelacourse at 08:31, 2009-02-20
-- Edited by davelacourse on Monday 16th of March 2009 05:23:45 PM