Last ride I thought it sounded a little noisy at idle so today I pulled the alternator and voila bolt head sheared off. I was able to remove the remaining bolt from the alt shaft with an easy out. The old bolt was a 6mm with grade 10.9 stamped on the head. Is the center bolt supposed to be 6mm or 8mm ? Looking through Mustangs how to thread his bolt looks like 8mm. I'm debating on reassembling with an ARP 6mm or take the alt to a machine shop and have the shaft tapped to 8mm. What do the experts say 6mm or 8mm ?
Thanks
Chris
As far as I can see based on the Interweb, its a 6x16 HI-tensile bolt (10.9, US grade 8)
According to my Parts list, orig part no is 3150025-T0301
If the threads are OK, then a 10.9 OEM. or 12.9 grade replacement 6mm HT bolt and some good quality thread lock should sort it for a good while.
Mustang notes, in his thread that due to leaving it too long, the loose bolt had fubared the thread in the armature, requiring the 8mm rethread.
I'd stick with a 6mm HT and some thread lock, and dependant on you splines, maybe some bearing retainer.
Regards
Phil
Quote from: London_Phil on May 03, 2015, 03:34:09 PM
As far as I can see based on the Interweb, its a 6x16 HI-tensile bolt (10.9, US grade 8)
According to my Parts list, orig part no is 3150025-T0301
If the threads are OK, then a 10.9 OEM. or 12.9 grade replacement 6mm HT bolt and some good quality thread lock should sort it for a good while.
Mustang notes, in his thread that due to leaving it too long, the loose bolt had fubared the thread in the armature, requiring the 8mm rethread.
I'd stick with a 6mm HT and some thread lock, and dependant on you splines, maybe some bearing retainer.
Regards
Phil
I re read Mustangs post and you are correct. I also found a different on line parts diagram that show this as a 6 x 16mm bolt so that is what I need to source tomorrow hopefully I can find one locally.
Thanks for the clarification.
What a PITA trying to get one 6 x 16mm high strength bolt. I did manage to find a 12.9 grade and got it all back together with some red loctite, nice and quiet now we'll see how long it lasts.