ORIGINAL: locktite401
Of all the traditional diesels, PAW's must be the most difficult there is to unscrew the backplate. It's designed to be removed with the aid of a UK 10P coin IIRC.
This almost never works for me.
Heating the rear of the engine is most difficult 'cause if you heat the crankcase the backplate will also expand.
One foolproof technique I found is to carefully grasp the backplate rim in a 3-jaw chuck of a lathe and place a towel over the engine.
Twist the chuck and engine in appropriate opposite directions, gently tightening the chuck till it just grips.
So far it's worked every time.
Ray
Hi Ray,
what has worked for me with my PAW 19 and 15 in regards to the screw in backplate is heat around the back on the case (but try and avoid the back plate obviously) and then place the upwards facing engine's back plate onto an ice cube.
Then of course the old mud guard washer gripped in a vice is used as a key, but must admit that even then it involves some muscle!
You are lucky having a lathe mate.
Cheers.