Well, I’ve spent quite a bit of time looking through the M-O, overhaul manual and the 100 series service manual looking for a couple torque values with no success. They may be there, but I’m not seeing them.
Can anyone tell me the torque value for the following joints? Below are pictures with the fasteners in question.
-Starter to engine crankcase (I replaces seals and gasket)
-Engine mount to engine main bolt through the isolator (the main bolt is an AN7, I’m not sure the size of the the cross bolts. I’m replacing a broken grounding strap.)
Doug,
I've also come up empty-handed for a specific starter bolt/nut torque. I thought I might find it in the O-200 Overhaul Manual or in Niagara Air Parts ICA info but couldn't find it in either place. Cessna SL65-62 contains Continental Bulletin 65-6. It specifies a general torque for 5/16 - 24 fasteners as 200 +/- 20. This value is also found in Continental Bulletin M64-23, Continental Service Bulletin SB96-7C and Table B-5 of Appendix B in Continental Maintenance Manual M-0. The latter says, "If an application is not listed, then the general torque value must be used."
The 1/4 X 28 bolts that squeeze the lord engine mount bushings require a torque of 90-100 In.-Lbs. according to Manual M-0 in Table B-2 on page B-6. Finally, here is a screenshot from the 69-76 Cessna 172 Service Manual:
Thank you so much for sharing this information. I now see the “engine mount leg bushing” torque in the M-O. I probably read that a few times but didn’t pick up on it.
My A&P and I did end up picking the general torque value for the starter from M-O. We couldn’t believe the engine mount would just use a standard torque, though.
I hadn’t gotten around to looking at later service manuals. That is a great find.
Thanks again for the time you put into researching answers for the association members.
Alright, I think I've finally found the correct nut and bolt torques for mounting the starter. It's found in Continental Critical Service Bulletin CSB96-1. The last page of that Bulletin, section (B)(5), states, "Torque nuts (3 each) to 180-220 in/lbs. Torque bolts (two each) to 155-175 in/lbs.
n2582d wrote:Alright, I think I've finally found the correct nut and bolt torques for mounting the starter. It's found in Continental Critical Service Bulletin CSB96-1. The last page of that Bulletin, section (B)(5), states, "Torque nuts (3 each) to 180-220 in/lbs. Torque bolts (two each) to 155-175 in/lbs.
That 1996 “Critical” Service Bulletin has an interesting applicability-statement:
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention. An originality nut (mostly) for the right reasons.
Well, the good thing is that most of those numbers are near or fall into the 200+/-20 range which is the general torque. I went ahead and tightened them to 190.
