I'm trying to salvage a 1976 that was flooded. Got it running, and now I'm trying to flush the transmission. I've dropped the pan and cleaned it, new filter,. opened the line at the radiator, and so far ran 8 gallons of new fluid through it. Although it's starting to darken a little it still looks like a strawberry milk shake. Is there someone that can give me instructions on installing a drain plug on the converter while it's on the car? preferably with a picture or two. It' got a 350 turbo in it. thanks

 

The thought of drilling / tapping a hole into the convertor is scary. If any shavings got into the tranny orfices, ..... well, . . . . . . .

The other issue would be that a threaded plug would add weight, might change the balance of the unit. Sorry, but not recommended.

 

Here is a link:

https://itstillruns.com/install-torq...g-5087693.html

Some aftermarket (and factory) converters do come with drain plugs. You can research via Google and find some approaches to install a pipe plug. That said, you would need to have the unit re-balanced by a properly equipped shop in order to avoid severe vibrations. All this would need to be done with the unit out of the car. At that point, unless it is already aftermarket and you have a significant investment, if it were me I would invest in a new converter. Just my opinion.

 

Yea....
Not recommended as shavings and balance issues. Easy enough to flush trans by pumping into a bucket couple qts at a time if you want a "complete" flush. Or simply change the fluid a couple of times.

 

There used to be a procedure in the GM service manual to install a drain plug in the convertor.

 

If your transmission got filled with water the paper friction clutches are already ruined. To install a 1/8" NPT Allen head drain plug in your torque converter drill the middle of the center band with an 1/8" drill bit and let it drain completely (it'll take a couple of hours). Then drill it with an 11/32" (.343") drill bit. Then tap the hole with an 1/8" pipe tap and screw an Allen head pipe plug in. If the plug won't go in deep enough you'll have to grind your tap about 1/4" shorter then tap the hole several threads deeper. Work slowly as you don't want the plug to go in too deep (half way is ideal).

Here's a picture of the tapped hole in one of my old TH700R4 torque converters. The TH350 is similar in appearance but the trick is to drill the band in the exact center and only deep enough to allow the oil to drain. I always drill and tap mine in alignment with one of the flex plate bolts and then I spray white paint on it so it's easier to find.

 

If you're worried about the balancing, then put 2 plugs 180* apart in it so they balance either other out.

 

The torque converter shell is 11 gauge steel (.125" thick) and the plug ALMOST weighs the same as the material removed. My '82 only has one drain plug but my '71 has two; 180 degrees apart just so I wouldn't have to turn the engine over so far to find a drain plug. The amount of unbalance of one drain plug isn't enough to notice; even at 6000 rpm.

My '68 Plymouth had two OEM drain plugs 180 degrees apart and that's where I got the idea to install drain plugs. They sure make it nice when I'm doing an oil change.

 

Your best option is to REPLACE the torque converter. Do a Google search for a wholesale supplier of transmission components in your area. They are everywhere, as they supply transmission repair shops with their parts. Call and find out if they sell to the public. Many do, but there is a price difference from 'business' transactions.

Give them the numbers found on the data plate on the transmission and they can supply the proper torque converter for your unit.

"Messing around" with a torque converter is NOT a good idea. Drilling holes and installing plugs can be hazardous to your safety in two ways:

1. ANY machining into a metal part can cause stress risers...points where cracks can start to form when the part is highly stressed. Having stress risers in the outside surface of a metal part filled with 10-15 pounds of transmission oil, while spinning at 5000 [or more] RPM is NOT a good idea.

2. The torque converter NEEDS to be well balanced so that it can rotate at high rotational speeds without vibrations. "Guessing" at part balance by machining threaded bores into the O.D. of the part and installing similar metal plugs is very risky.

Before you go to the effort of 'salvaging' a [likely worn-out] very old transmission part, please consider whether the well-being of your car and your personal safety are worth $100.

There are things that "Bubba" can gin-up and get by with. This IS NOT one of them.

 

Nicely put.

 

toobroketoretire is back. I'm sure toobroketoretire posted this same info along with that picture at one time. The picture is familiar as well as that bit about the Chrysler converter having 2 drain plugs.

 

they sell a special leak proof pop rivet to do this. check your auto parts

 

And you still have the metal shavings issue.

 

talk to a transmission shop about this, then if they think the can overhaul it, pull the transmission and take it to them, exchange the tork conerter and put it back in yourself to save money. I did mine , it was not that much to overhaul it, but check out the shop beforehand, or if you know them,ok.

 

Back in the early 80's I worked in the same shop with a Trans man, he did this to most of the transmissions that he did a service on, never an issue. The fluid running out will flush out any drill shavings that might have got in. The Pipe tap is coated with grease to hold the chips, and if you wish, just spray some brake cleaner in the hole and let it flush out. I've seen the GM bulletin on this, it used to be common. I would do it in this situation to see if the rest of the trans was going to live before I spent very much money on it.

 

you put grease on the drill bit and have someone hold a shop vac hose near where you are drilling. also the filter in the pan will catch any that you miss.

 

I've been thru shops that refurbish torque convertors and they all cut the converter open, remove and rebuild the guts (if condition allows), then braze the shell back together and rebalance it. Only a Bubba-shop would cut a hole in it and install a plug.

If you choose to do that to your converter, make sure to wear some steel-mesh shorts before you wind it up....

 

Pretty sure the sky won't fall, usually doesn't!

 

I have to say I go with the not a good idea crowd.

 

Just now figure that out?