I attempted to remove the only plug on m21 tranny to change fluid, but was unable to get the plug out it appears to be seized. Heat was applied to plug,extensions on wrench was tried with no success any tricks of the trade to remove the plug.


Thanks guys for the advice I really appreciate it.

 

Cut a slot through the middle of the plug and use a very sturdy square shanked screw driver and suitable wrench to turn screw driver. Might have to drill it out. Then use a brass hex headed plug instead of cast iron.

 

If you don't need it out today spray it everyday w kroil or pb blaster and let it sit. Then in about a week really heat it good, try longer a longer breaker bar by jacking the car up for more room

 

Impact wrenches can do wonders
you don't specify but if it is a square head then I suggest an 8-point socket and Hugh Jass breaker arm or long arm ratchet if you do not have air tools or access room for air tools. 1/2" drive or bigger.

Oh and the heat should be applied to the female surrounding part, not the male plug, what with heat making things expand and all that.

 

It is the square head plug,thank you for the advice I will give that a try.