The International Cessna^® 170 Association

I am looking for the engine mount torques for the engine mounts on a C-170/C-172. NOT the mount to firewall and not the large bolts (4 in #, 7/16 bolts) but the bolts that are on each engine to mount. There is a total of 8, 2 on each mount. Anybody have any idea?

Thanks!

I imagine you are talking about the 1/4-28 leg bushing clamp nuts. If thats the case they are torqued to 90 to 100 inch pounds per the tcm SB96-7C. Hope this helps

mrpibb wrote:I imagine you are talking about the 1/4-28 leg bushing clamp nuts. If thats the case they are torqued to 90 to 100 inch pounds per the tcm SB96-7C. Hope this helps

He said "engine to mount", so I thought he was talking about the 3/8 bolts and studs that hold the "feet" to the case. For each foot there are two studs and a tie bolt, and their torque should be found in the overhaul manual. Sorry, but I don't have mine with me.

Don't forget that the front tie bolt needs o-rings between the feet and the case, as that bolt is not in a web in the crankcase and is open to oil splash. It WILL leak if the o-rings aren't there. See the first installment of my engine overhaul article in the 2nd Quarter 2006 170News. There are more/better pictures at http://www.geocities.com/cessna170bdriver.

Miles

Vic

To be clear that is the standard torque for a bolt that size. You could be right and in the absence of other data you are right.

I thought I saw these engine legs listed somewhere with a torque spec but dam if I can remember where or find it now.

The torques I listed were for the engine mount leg clamp bushing. He mentioned 8? (1/4-28 ) ? fastners so i precluded the mount leg to case where there are studs and thru bolts. Thru bolts nuts and stud nuts for the mount legs to case are of course different torque values.
If anyone would like a copy of SB96-7C PM me

PS SB96-7C is the TCM service bulletin on torque limits, If ya didnt know.

Vic,

You're most likely right; just goes to show the importance of part numbers and/or IPC figure and index numbers when asking questions.

Miles

Vic

I looked at the SB and didn't see the legs specifically which is why I thought you might be specifying the standard torque. I'll look at the SB again.

This is the most likely place I saw this torque before that i can't find now.

For your viewing pleasure http://www.tcmlink.com/pdf2/SB96-7C.pdf. Nut- engine leg bushing, nut- mounting brackets to crankcase and nut-crankcase tie bolt

There is that darn info. Third one down on the third page. I knew I saw that somewhere.

Hope I can find it next time I need it.