The drain plug on my autotrans (4L60E) won't come out (2003 GMC Denali). It appears to use a 15mm socket as that is what fits very tight and full.

With a 3/8ths rachet, I am beginning to round the plug before it ever wants to move!

Don't know that this has been out before, did they put some sort of sealer or locktite on the plug to keep if from leaking?

Am afraid that I will have to pull the pan to get the plug out.

All I really started out to do was change the filter and fluid.

HELP.

Bob