how to drain and clean torque converter

I just rebuild my 4l60e in my 97 Blazer. I'm unable to buy a new converter so i want to clean out my old one.

When rebuilding the tranny there was no metal shaving at all but the fluid that came out of the tranny was badly burnt.

Is it possible to drill a hole somewhere in the converter and then weld over the hole after it's cleaned out. And what size hole do I drill.

Any help in this matter would be greatly appreciated.

Is it possible to drill a hole somewhere in the converter and then weld over the hole after it's cleaned out..

In the good old days, converters had drain plugs. Not now, though :(

I have never done this myself but I have heard that this is done fairly often, particularly for older, more rare converters, where replacements are not easy to get.

Drill a hole on the welded seam where the two outer halves are welded together. Do not drill where you see a corrugation or depression. No sense in disturbing the blades inside.

Size? Imo start pretty small, maybe 1/16 inch and see how that works. If you find oil stops flowing, there might be some debris is lodged in there, so a larger hole might be needed. Of course a bit of comressed air down the neck would help things flow.

If there was no glitter in the old trans oil, you can simply invert the converter and set it on a coffee can or similar container. After about 20 minutes, flip the converter again, agitate it a bit to circulate more oil (you'll see oil collect in the hole at the turbine hub), and set it up to drain again. You can repeat this a few times and get all but the last few ounces out that way. The rest will get pumped out when the trans oil pump runs and any debris should get caught in the filter. Whenever I freshen up a trans I like to either get my hands back on it in about 1,000-2,000 miles and/or instruct the owner to drop the oil and install a fresh filter. I like to look at the burnished particles in the pan to make sure that only the friction surfaces are wearing in and any metal from cleaned up steels and the drum is miniscule. In doing a short oil and filter change you'll remove all the new friction material that polishes off in the first few thousand shift cycles and trap anything left behind like gasket fragments and lint. The new filter and fresh half load of oil should set up the trans until its regular 30,000 mile service.

you could add a drain plug, but you would DEFINITELY have to have the TC balanced by a shop afterward. googling came up with a few results....