TR2/3/3A Proper size of "set screw/bolt?" for top of trans.....

[karls59tr]

Bellhousing where it mounts to motor. The four or five bolts along the top. I may have stripped out A couple of these bolt holes or I'm using the wrong size bolt as it's very difficult to tighten them. I may have to clean them up? or retap them one size bigger. Anyone know what size these bolts are supposed to be and are they referred to as set screws?

 

[TR3driver]

The 3 at the top should be studs rather than bolts. The end into the cylinder block should be 5/16 NC, the other end 5/16 NF. 1.25" long.

I believe the reason for using studs here is that the holes are too shallow to effectively use bolts. (Using studs ensures that the full length of threads in the hole are used; bolts have to be short enough to not reach the bottom.)

Not sure about Canada, but any hardware store in the USA will know them as "bolts". But the British terminology is (or at least was) rather different, they use "setscrew" to refer to a bolt that is fully threaded.

If you do have to repair them, I strongly suggest using a Helicoil insert rather than tapping oversize.