|Berghandler said: (quoted from post at 11:58:57 01/10/13) I'm about to put a new ring gear onto exsisting flywheel. Old ring gear came off very hard but OK. Noticed on diameter of flywheel where ring gear was seated that it's a different diameter than further away from this area. There are definately two diameters and the one further away from the flywheel shoulder is larger. This means that in cooling flywheel down and heating ring gear I must hope for enough growth/schrinkage to be able to slip/tap ring gear over a larger diameter than the diameter it actually seats on. I looked at old ring gear inside diameter and both outside diameters on flywheel and saw NO EVIDENCE of the ring gear spinning and causing the difference in diameter. No pickup or scoring of any kind. With a steel ring gear and a cast flywheel there should have been something noticable if ring gear had spun. It almost looks like it's been manufactured that way. Has anyone out there seen this slight difference in the diameter where the ring gear goes onto the flywheel, (looks like maybe .010" on a dia. larger at first then smaller against the shoulder)? Would be nice to know that new ring gear will fit OK onto this flywheel. Have no way of accurately measuring these diameters.|
The shoulder is machined into the flywheel at teh factory. The ring gear has to be expanded (heated) enough to fit over the shoulder and that is more than most people think. Someone took some measurements and did the math recently:
OD of shoulder on flywheel - 12.022
ID of new ring gear - 11.964
Expansion needed = 12.022 - 11.964 = .058
Expansion factor for steel is roughly .00064/in /100F so your 12" ring gear will expand roughly .007 inches for every 100 degrees you heat it. To get .058 inches of expansion that is (.058 / .007) x 100F = a bit over 800F. Or heat the ring gear 500F and cool the flywheel 300F :wink:
TOH This post was edited by TheOldHokie at 08:34:20 01/10/13 2 times.