1.502 inches as AF Socket
 

Hello All,

I just measured the crankshaft bolt on a Perkins 6354 diesel motor. The micrometer showed a reading of 1.502 inches or 38.16 mm.

Is the fractional measurement of 1.5 inches in a socket a tight enough fit or should I buy a socket that is measured a smaller fraction, such as a 16th or a 32nd?

I need to buy a new socket as none of my current stock fits the Perkins crankshaft bolt.

Kind regards
Lionel

Wrench clearances
 

Hi Lionel,

Just had a look at my Machinery's Handbook.
From American Standard Wrench Openings (ASA B18.2 1960):

Minimum AF opening for a 1-1/2" wrench is 1.508" and maximum opening is 1.520"

Checked Whitworth sizes and according to a newer standard BS 1083 the nearest bolt head sizes AF for BSW/BSF is 1.46 to 1.480 which is a little bit less than yours. An older standard BS 190 has the identical AF sizes. Next size up is too big in both cases.

Based on the above a 1-1/2" AF should be OK. This assumes the Chinese tool makers comply to American Standards.
Six point flank drive impact sockets also compensate for rounded corners which may be a consideration over a standard 12 point socket.
Another possibility is using a 38mm metric socket. 1.502" = 38.15 mm. If the wrench clearance is adequate it might fit but would be best to measure the Distance AF on the socket before buying. As I mentioned in an old post a 28 mm deep impact socket works great on the imperial 7/8 BSF wheel stud nuts on CMP two piece rims. So sometimes metric sizes comes to the rescue even with imperial fasteners.
It might be a lot cheaper and easier to find a metric socket too.

Hope this helps.

Hello Jacques,

Thank you for your reply and for posting the detailed information. an 1 1/2 inch hex socket fitted perfectly.

I have learnt the lesson about using hex sockets on high torque items instead of 12 pointers. Especially, after the 12 pointers butchered a couple of flex-plate nuts when I previously had tried to remove a torque converter. One reconditioned torque converter later....an expensive lesson it turned out to be!

Unfortunately, with the new socket I was able to prove the engine's previous owner's theory; that the motor is seized after it sat idle for a number of years. Pouring a mixture of diesel and liquid lanolin penetrant down the diesel injector holes a fortnight ago did not work miracles.

Kind regards
Lionel