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techtalk:ih:engmech09f [2021/06/10 20:39] – created hippysmacktechtalk:ih:engmech09f [2023/12/27 22:12] (current) hippysmack
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 ====== Broken / Cracked Rear Mounts ====== ====== Broken / Cracked Rear Mounts ======
  
 +Originally, the rear motor mount was made of steel and had 4 bolts in the top. ((piniongear at HD Forums https://www.hdforums.com/forum/ironhead/633728-ironhead-rear-motor-mount-stud.html)) \\
 +Later it was made of aluminum and prone to cracking. The steel mount will never crack. \\
 +The first aluminum mount had 4 bolts in the top. Later the mounts had only 2 bolts. \\
 +Aluminum mounts are going to crack. If you have a brand new replacement mount in hand right now, it will crack. \\
 +Should your mount be a steel one, then it is worth installing. But, the cracks do not present a real problem though. \\
 +That is the good news. \\
  
 +Sometimes the mount cracks all the way across as in the pics below.  \\
 +Whilst many of them tend to crack, some only crack so far and then stabilize. ((simonster123 of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/86472-stock-vs-pingel/page2?t=670768&page=2)) \\
 +Unless it's completely cracked through or flexing like mad, you can run it and monitor whether or not it gets worse. \\
 +So it's not necessarily a problem that has to be fixed depending on how badly cracked it is. \\
 +However, it does reduce vibration to repair or replace. \\
  
 +And even if the aluminum mounts are installed correctly, they will still crack. They seem to crack worse after welding. ((Dr Dick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/126465-rear-motor-mount-help/page2?t=1283746&page=2)) \\
 +It may be best to score a 57-60 steel mount (a 52-56 k model mount will work too if you ain't got a kickstart) and cut it to mimic the -67 mount. \\
 +You can try to have the crack welded as in the pics below. \\
 +You can also replace it with an aftermarket mount. Pingel has a high reputation as an aftermarket alternative. \\
 +See [[techtalk:ref:engmech09#pingel_rear_motor_mount|Pingel Rear Motor Mount]] in the REF section of the Sportsterpedia. \\
 +The heavy aftermarket works but it takes up more room and you gotta screw around with the lower oil tank mount if you're working on a 70-78CH. \\
  
 +This one is cracked all the way across. \\
 +{{techtalk:ih:engmech:cracked_motor_mount_1_by_jsandidge.jpg?direct&300|}} ((photo by jsandidge of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/198233-cracked-motor-mount/page4?t=2074969&page=4)) {{techtalk:ih:engmech:cracked_motor_mount_2_by_jsandidge.jpg?direct&300|}} ((photo by jsandidge of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/198233-cracked-motor-mount/page6?t=2074969&page=6)) \\
 +
 +This one is only cracked for a small distance. \\
 +{{techtalk:ih:engmech:cracked_motor_mount_on_73_ch_1_by_killer_ch.jpg?direct&300|}} ((photo by Killer CH of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/130889-rolling-basket-case-saga-now-it-s-the-rear-motor-mount?t=1384261)) {{techtalk:ih:engmech:cracked_motor_mount_on_73_ch_2_by_killer_ch.jpg?direct&300|}} ((photo by Killer CH of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/130889-rolling-basket-case-saga-now-it-s-the-rear-motor-mount?t=1384261)) \\
 +
 +This one from a 68 XLCH has been welded. \\
 +
 +{{:techtalk:ih:engmech:welded_rear_motor_mount_on_68_xlch_pic_1_by_kennycoulter.jpg?direct&300|}} ((photo by kennycoulter of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/117858-wiring-placement-pictures-or-diagrams/page3?t=1139862&page=3)){{:techtalk:ih:engmech:welded_rear_motor_mount_on_68_xlch_pic_2_by_kennycoulter.jpg?direct&300|}} ((photo by kennycoulter of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/117858-wiring-placement-pictures-or-diagrams/page3?t=1139862&page=3)) {{:techtalk:ih:engmech:welded_rear_motor_mount_on_68_xlch_pic_3_by_kennycoulter.jpg?direct&300|}} ((photo by kennycoulter of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/117858-wiring-placement-pictures-or-diagrams/page3?t=1139862&page=3)) \\