Found a leak on the output shaft seal on my 4t65e. I went to replace the seal and found this damage to the case. looking at the seal, I don't think this should be a big deal as the sealing appears to happen further down into the hole and the fluid shouldn't even make it up that far. Im thinking of taking some JB weld and shaping it into the gash, or maybe using the high tack sealant that im going to use around the gasket to fill it, but im not sure If I should even bother.

Adivce?

Take some 150 grit sand paper and smooth out only the high spots on the outside edge and try to keep the grit outside of the trans. Then apply a thin coat of silicone sealant to the new seal (outside edge only) and drive it in. If you don't have the correct driver, the seal is easier to drive in if you take the diff cover off the other side and slide the diff out of the trans a couple inches. This will pull the drivers side output shaft into the trans so you don't hit it with a flat driver tool. But be careful, you have to line up the inner thrust bearings on the pass side before putting the diff back in, and you will want to set the bearing in place with some trans assembly grease so it doesn't fall out of place when assembling.

I sanded down the high spots with 180, put Red RTV to fill the gash, and coated the surface of the new seal with High Tack sealer. We'll see how this went tomorrow.