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Duke - I am copying my post from below into a new thread per your suggestion, here it is:
Duke and George - you are right, this thread is getting long. I have taken the advanced 5 hour evening class from Steve Hack (Eastern Corvettes) on this topic, which also included the windshield wiper motor repair.
First, the points you reference are a thermal overload protector, with a bimetal strip that heats up and opens the points when the motors bind, draw too much current, and is designed to prevent thermal overload of the armature windings. This phenolic plate is held in place with two spring steel clips, and you can pull hit out over the armature end. It also contains the spring loaded carbon brushes and springs, so be careful when you remove it you don't loose parts. Its sort of like working on an alternator. These brushes NEVER wear out, and are not replaced. they see so little run time they virtually last forever. Once the brush assembley with integral points is out of the way, you can extract the armature. If it does NOT come out freely, don't pull! There is a spring loaded heim ball shaped bronze oilite bearing in the rear housing that is self aligning. It is VERY common for the armature shaft to freeze to the bearing, and then the total bearing spins in the spring clip alignment asm I mentioned. This happens frequently, and results in slow running motors with excess current draw. To get the bushing loose, and this is touchy (Steve does it all the time and has excellent luck) you need to carefully push the armature TOWARDS the thumbwheel end, and when holding it against the end bell, use a small torch to heat the housing NEAR the armature, keeping the bronze bearing in contact with the end bell with force from your other hand. Mount the hosing loosely in a vise. If you don't push the armature towards the end bell, you won't heat the bearing up, just the case, and accomplish nothing. The trick is heating enough to expand/loosen the bearing so you can carefully tap the armature loose with a small brass hammer, without overpowering and forcing the bearing through the spring steel cage. This cage, once it pops through (and it will) is a one way affair, and to repair AFTER you do that (and I know, I did) yo have to follow the three screw capture process I explained a couple weeks ago in a long post (you can search for it). Also, don't overheat the armature when you perform this operation, as the the end play is controlled by a PLASTIC section on the armature, and it WILL MELT if too hot. You can also burn up the plastic plug housing if you are not careful. So...my first crack at this did not succeed, and I ended up with the bronze ball coming out with the armature. It was very tight, and I carefully worked it loose, and used the 3 screw floatiing repair process.
As Duke says...NEVER use wheel bearing grease, only WHITE LITHIUM. This is the correct grease to use in these assemblies. In the gearcase, pay careful attention to the cupped sring washer placement etc. Steve DOES adjust the end play to control the motor timing, but you must maintain at least minimal play that you can feel when you grab the armature (as Duke mentions 10-20 thousandths is reasonable). IN spite of the thinking that you would have to bind the end play to slow, it does seem to be controllable even with some end travel. We timed a pair in the class at Bloomington, and Steve puts a small mark on the end of the pot metal gear on the end you see in the housing (end opposite engaged end) and times the rotation for say 20 seconds, counting the number of revolutions, and adjust one or the other motor so they are similar. Both still had end play when done.
Hope this helps!....Craig
Duke and George - you are right, this thread is getting long. I have taken the advanced 5 hour evening class from Steve Hack (Eastern Corvettes) on this topic, which also included the windshield wiper motor repair.
First, the points you reference are a thermal overload protector, with a bimetal strip that heats up and opens the points when the motors bind, draw too much current, and is designed to prevent thermal overload of the armature windings. This phenolic plate is held in place with two spring steel clips, and you can pull hit out over the armature end. It also contains the spring loaded carbon brushes and springs, so be careful when you remove it you don't loose parts. Its sort of like working on an alternator. These brushes NEVER wear out, and are not replaced. they see so little run time they virtually last forever. Once the brush assembley with integral points is out of the way, you can extract the armature. If it does NOT come out freely, don't pull! There is a spring loaded heim ball shaped bronze oilite bearing in the rear housing that is self aligning. It is VERY common for the armature shaft to freeze to the bearing, and then the total bearing spins in the spring clip alignment asm I mentioned. This happens frequently, and results in slow running motors with excess current draw. To get the bushing loose, and this is touchy (Steve does it all the time and has excellent luck) you need to carefully push the armature TOWARDS the thumbwheel end, and when holding it against the end bell, use a small torch to heat the housing NEAR the armature, keeping the bronze bearing in contact with the end bell with force from your other hand. Mount the hosing loosely in a vise. If you don't push the armature towards the end bell, you won't heat the bearing up, just the case, and accomplish nothing. The trick is heating enough to expand/loosen the bearing so you can carefully tap the armature loose with a small brass hammer, without overpowering and forcing the bearing through the spring steel cage. This cage, once it pops through (and it will) is a one way affair, and to repair AFTER you do that (and I know, I did) yo have to follow the three screw capture process I explained a couple weeks ago in a long post (you can search for it). Also, don't overheat the armature when you perform this operation, as the the end play is controlled by a PLASTIC section on the armature, and it WILL MELT if too hot. You can also burn up the plastic plug housing if you are not careful. So...my first crack at this did not succeed, and I ended up with the bronze ball coming out with the armature. It was very tight, and I carefully worked it loose, and used the 3 screw floatiing repair process.
As Duke says...NEVER use wheel bearing grease, only WHITE LITHIUM. This is the correct grease to use in these assemblies. In the gearcase, pay careful attention to the cupped sring washer placement etc. Steve DOES adjust the end play to control the motor timing, but you must maintain at least minimal play that you can feel when you grab the armature (as Duke mentions 10-20 thousandths is reasonable). IN spite of the thinking that you would have to bind the end play to slow, it does seem to be controllable even with some end travel. We timed a pair in the class at Bloomington, and Steve puts a small mark on the end of the pot metal gear on the end you see in the housing (end opposite engaged end) and times the rotation for say 20 seconds, counting the number of revolutions, and adjust one or the other motor so they are similar. Both still had end play when done.
Hope this helps!....Craig
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