Hello Ted,
It sounds like it could be the motor bearings and/or the motor coupler. It is best every ten years, to remove the motor and the rotor from the motor. Make sure when you slid out the rotor, to keep track and orientation of the spring washers that pressing against the bearings and bearing face. Put the rotor on a wood mount on a bench, so you can rotate the bearings by hand with out the rotor moving around. After about 10 years, you can feel a roughness of the spin. Anyway, it's a good practice to replace the bearings about every ten years. Measure the diameter of the bearing and go to a auto parts store to get a bearing splitter to fit that size bearing. Its like a wheel puller, except it has a large flat beveled plates that the edge can slip behind the bearing. After you remove the bearing, take them to a bearing shop or to a motor shop for a replacement. There are different grade of bearings. These motor bearings should be a permanent type motor bearing. The bearing shop or motor people can verify what shape these bearings are in by giving a hand spin test. At the same time take the rotor and the motor coupler to the motor shop and ask them to check the condition of the commentator and the input and output shaft drives. What happen to my taper lock motor coupler one time, is that the taper lock bushing crack which cause a mechanical noise at a certain rpm. It is best at this time, to have the commentator electrical tested, hot dip into motor enamel, turn and undercut. Have the motor end shafts true up. Also have the rotor test balance with the motor coupler on the motor shaft. It is important that the commentator is coated with motor enamel, so that the segment grooves are insulated, which prevent brush dust from tracking between the commentator bars. The motor shop will then turn and surface the commentator at this time. Check the condition of the brushes, the length left from the original length. Estimate how many years you can get out of these brushes before replacement or replace the brushes if needed. Pick up a can of motor spray cleaner to clean the fields and housing of the motor. The last time I did this maintenance, I also pick up a can of motor spray enamel that I used to recoat the entire surfaces of the interior of the motor housing, end bells, and even on the front of the commentator up to the edge of the bearing surfaces. This prevents brush dust tracking onto the motor shaft to ground. After assembling the motor, take a ohm reading from all the motor terminals to the motor case. This should read up to 20 meg ohms. As the motor ages, this reading will reduce into the k ohms. If the ohms reading go's below 30 k ohms, then its time to do this maintenance. Roland ----- Original Message ----- From: Ted Lowe, FVEAA via EV<mailto:ev@lists.evdl.org> To: Electric Vehicle Discussion List<mailto:ev@lists.evdl.org> Sent: Wednesday, March 04, 2015 9:33 AM Subject: [EVDL] Damaged ADC FB1-4001A Motor Hi EVers, i have a 1992 S-10 conversion i've been driving for 14 years. It has an ADC FB1-4001A 9" motor. Last year i made a mistake and over-spun the motor with the clutch activated. The motor made a big nasty mechanical sound and i thought i would be walking home from there. But the motor still works as long as i keep the RPMs down (perhaps below 2000). If i go above that RPM, the banging sound happen again. i realize i'm driving 'on borrowed time' and want to get the motor fixed/rebuilt. So my questions are: 1) What is likely damaged inside? 2) What would be involved in getting it repaired? 3) What kind of parts and costs are likely involved? 4) Can this be a DIY project for a handy person? Thank you! Kind regards, ted _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub<http://www.evdl.org/help/index.html#usub> http://lists.evdl.org/listinfo.cgi/ev-evdl.org<http://lists.evdl.org/listinfo.cgi/ev-evdl.org> For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA<http://groups.yahoo.com/group/NEDRA>) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20150304/af7a9f87/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)