80 clutch r/r howto
09-17-2013, 03:09 AM
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Burning Brakes
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80 clutch r/r howto
I thought I would share my recent 80 5 speed throw out/release bearing replacement while it's fresh in my memory. I did a clutch on a 78 several years ago and my memory of the process failed me, it was a monster struggle to get out and back in the first time on this 80 couple days ago. I say first time because it took 2.5 attempts before we got it right. Note: I enjoyed the use of a lift, a professional's toolboxes, shop manuals, and a 30 year Aston Martin mechanic-par-excellence assistance/lead.
1. Put the car in the air, battery disconnected. Jack stands work just fine, give yourself as much room underneath as possible.
2. You may need to loosen the exhaust to make room. Don't recall doing this on the 78, this beast has headers so we removed collector bolts and loosened all the header bolts at the head. Don't have to take them off, just let the headers wiggle to the side. Gotta make room for the lower bellhousing.
3. Remove slave cylinder bolts (2 x 13 mm), pull the slave cylinder back and remove the actuating rod.
4. Remove lower bell housing (6 x 13 mm bolts). Leave the starter attached, bungee chord it from the suspension out of the way.
5. Remove input shaft/torque tube shaft sleeve (2 x 8mm hex). You will need to rotate the engine (1 1/16" socket) at the forward crank snout to get access to both bolts. Slide the sleeve back to reveal the input shaft.
6. Fabricate 3 U-shaped (locally sourced spacers) to fit under the pressure plate pressure pins (flat hats attached to spring material on a shaft). We used welding rod, cut to 2 inch lengths, hammered around a socket extension shaft to achieve desired curve. You can 'actuate' the clutch with a large pry bar on the clutch arm (the slave cylinder operates this arm) if you don't have enough room to get the spacers in. Place a spacer under each flat hat. This removes the preload on the pressure plate.
7. With a hammer and punch, push 3 x 3mmish pins out of the flywheel towards the rear of the car. You'll see them at 3 places on the silver inner plate with an extended gap section with nothing but the pin showing in the gap. We knocked the pins back until they were _just_ clear of the flywheel.
8. Remove 2 x 10mm bolts at the center of the clutch, they hold the t/o bearing guide tube to the bell housing.
9. Remove 6 x 13mm bolts from the pressure plate to the flywheel. Do this evenly i.e. loosen the bolts some, rotate, loosen, rotate. At this point the clutch is 'free' from the flywheel so be careful. Only thing holding it in now is the input shaft.
10. If necessary, pry the silver inner plate assembly away from the flywheel as you slide the input shaft towards the rear of car, disengaging the pilot bearing. The shaft only needs to come back to just before the edge of the bell housing inner edge where it meets the torque tube shaft. The whole assembly should come down now. Be careful, it's heavy.
11. Installation is the reverse of the disassembly, to quote the shop manuals. Ha! Just kidding, but mostly that's true. We found it easiest to
a) use some sort of jack to pump the clutch assembly back into place;
b) drive the pins back into the flywheel before you fully tighten the 6 pressure plate bolts;
c) tighten the 6 pressure plate bolts to 21 lbs;
d) don't forget to remove your locally sourced spacers from the pressure plate pins _before_ you put the lower bell housing on (
);
e) don't forget the guide shaft and all other ancillary bits to the t/o bearing before you put the lower bell housing on ();
f) the groove in the t/o actuating ring, contained by a snap ring, goes towards the pressure plate fingers ();
g) use good, high temp grease on the input shaft splines and inside of t/o bearing guide tube, but not too much, a very light coating is sufficient.
Kudos to 928 International for turning around a rebuilt t/o bearing in a couple days. These guys Rock. In so many ways.
Kudos to Ken Lovejoy, my buddy and professional mechanic. This guy has forgotten more than I will ever know about wrenching and his insight into how things work and the right way to do things was invaluable.
I hope this helps the next shade tree mechanic. Cheers and may the Bwaaahh be with you.
1. Put the car in the air, battery disconnected. Jack stands work just fine, give yourself as much room underneath as possible.
2. You may need to loosen the exhaust to make room. Don't recall doing this on the 78, this beast has headers so we removed collector bolts and loosened all the header bolts at the head. Don't have to take them off, just let the headers wiggle to the side. Gotta make room for the lower bellhousing.
3. Remove slave cylinder bolts (2 x 13 mm), pull the slave cylinder back and remove the actuating rod.
4. Remove lower bell housing (6 x 13 mm bolts). Leave the starter attached, bungee chord it from the suspension out of the way.
5. Remove input shaft/torque tube shaft sleeve (2 x 8mm hex). You will need to rotate the engine (1 1/16" socket) at the forward crank snout to get access to both bolts. Slide the sleeve back to reveal the input shaft.
6. Fabricate 3 U-shaped (locally sourced spacers) to fit under the pressure plate pressure pins (flat hats attached to spring material on a shaft). We used welding rod, cut to 2 inch lengths, hammered around a socket extension shaft to achieve desired curve. You can 'actuate' the clutch with a large pry bar on the clutch arm (the slave cylinder operates this arm) if you don't have enough room to get the spacers in. Place a spacer under each flat hat. This removes the preload on the pressure plate.
7. With a hammer and punch, push 3 x 3mmish pins out of the flywheel towards the rear of the car. You'll see them at 3 places on the silver inner plate with an extended gap section with nothing but the pin showing in the gap. We knocked the pins back until they were _just_ clear of the flywheel.
8. Remove 2 x 10mm bolts at the center of the clutch, they hold the t/o bearing guide tube to the bell housing.
9. Remove 6 x 13mm bolts from the pressure plate to the flywheel. Do this evenly i.e. loosen the bolts some, rotate, loosen, rotate. At this point the clutch is 'free' from the flywheel so be careful. Only thing holding it in now is the input shaft.
10. If necessary, pry the silver inner plate assembly away from the flywheel as you slide the input shaft towards the rear of car, disengaging the pilot bearing. The shaft only needs to come back to just before the edge of the bell housing inner edge where it meets the torque tube shaft. The whole assembly should come down now. Be careful, it's heavy.
11. Installation is the reverse of the disassembly, to quote the shop manuals. Ha! Just kidding, but mostly that's true. We found it easiest to
a) use some sort of jack to pump the clutch assembly back into place;
b) drive the pins back into the flywheel before you fully tighten the 6 pressure plate bolts;
c) tighten the 6 pressure plate bolts to 21 lbs;
d) don't forget to remove your locally sourced spacers from the pressure plate pins _before_ you put the lower bell housing on (
); e) don't forget the guide shaft and all other ancillary bits to the t/o bearing before you put the lower bell housing on (
); f) the groove in the t/o actuating ring, contained by a snap ring, goes towards the pressure plate fingers (
); g) use good, high temp grease on the input shaft splines and inside of t/o bearing guide tube, but not too much, a very light coating is sufficient.
Kudos to 928 International for turning around a rebuilt t/o bearing in a couple days. These guys Rock. In so many ways.
Kudos to Ken Lovejoy, my buddy and professional mechanic. This guy has forgotten more than I will ever know about wrenching and his insight into how things work and the right way to do things was invaluable.
I hope this helps the next shade tree mechanic. Cheers and may the Bwaaahh be with you.
