Front Axle Small issue on a 300DTC

[decableguy2000]

I have found and/or created a small issue. I was changing the oil in the front axle for the 400 hr service and can only get the center pipe plug to thread in one or 2 turns. tried swapping plugs with one from the knuckle with same results. Are the plugs standard NPT or some weird metric pipe plug?

 

[decableguy2000]

FYI it's 3/8 NPT, per the parts manual.

 

[fried1765]

FYI it's 3/8 NPT, per the parts manual.

Try running a 3/8" NPT tap in the hole, then replace the original plug with a new one.