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I was going to take a torque converter in to the tranny shop to flush it. It has no drain plug. I've heard of people drilling a drain hole and tapping it and installing a plug. Is this possible? Where to drill? What size plug? (It's a 700r4)
 

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Why are you flushing? regular maintenance or for an overhaul, is it a stockconverter or expensive aftermarket

If its stock just get a new one, not really worth a drain plug because if you flush the trans it will also get flushed

Brendan
 

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Yeah, you can drill a hole in the converter and reseal it with a closed-end pop rivet and some gasket sealer. You run the risk of damaging a stator if you don't drill in the right place. Instead of draining the converter, you can do a complete flush via the cooler lines without removing the converter.
 

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murrsue said:
I was going to take a torque converter in to the tranny shop to flush it. It has no drain plug. I've heard of people drilling a drain hole and tapping it and installing a plug. Is this possible? Where to drill? What size plug? (It's a 700r4)
I know a guy that used to build th400's for me, he always dilled and tapped an 1/8" pipe plug into the edge of the converter. I never had any problems and when changing the fluid and filter you could get all 10 quarts.
 

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cucumber1949 said:
Yeah, you can drill a hole in the converter and reseal it with a closed-end pop rivet and some gasket sealer. You run the risk of damaging a stator if you don't drill in the right place. Instead of draining the converter, you can do a complete flush via the cooler lines without removing the converter.
you would need to drill into the converter a couple of inches to hit the stator. You would damage the turbine and fins first.

the 700 converter or any lock up style converter can not be drilled on the front ( fly wheel side) since the converter clutch apply area is there at the outer edge of the shell
 

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I believe that there IS such a thing as a convertor flushing machine.

You have to have the convertor out of the car. We used to have units flushed when doing tranny overhauls.

Most of the Ford convertors (C4, C6) do have a drain plug, which is accessible through the flex plate. I don't know why GM never installed them.

As far as balance goes ... are there any weights on the convertor that could be drilled in order to compensate for the weight of the (1/8 NPT steel?) drain plug?

Crosley ... could you drill that 700R4 convertor on the trans side, then? Would the plug still be accessible?
 

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When I first had one done I asked about the balance issue, I was told and it makes sense that the plug is minimally heavier that the material removed from the converter. The guy that did mine used to build trans for drag racing.
 

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Was it "safer" a couple of decades ago?

Crosley said:
you would need to drill into the converter a couple of inches to hit the stator. You would damage the turbine and fins first.

the 700 converter or any lock up style converter can not be drilled on the front ( fly wheel side) since the converter clutch apply area is there at the outer edge of the shell
I was just thinking about the same thing. ~25 years ago, I rebuilt trannys for a living at double-A-beep-beep, and it was standard practice to drill, tap, flush and install an 1/8" pipe plug afterwards. The shop I worked at had no "flushing machine", but we'd pump solvent through them and spin the turbine with an input shaft. Probably did several hundred that way and never had a balance problem, but to be honest, I was never really fond of that method. Balance questions still remain in the back of my mind. I don't do that for a living any more, but still rebuild one every now and then for family and friends.

The reason I started thinking about this again is because I'm rebuilding my son's 4T60E this week that ground up a lot of hard parts when the support bearing on the output shaft disintegrated. Say goodbye to the input & reaction carrier, sun gear, 4th clutch hub, etc. So there's a lot of metal shavings everywhere. Now, I've got no problem sanitizing the internals during the rebuild.... except for the TC. I thought about drilling, tapping and flushing it, and still might, but first wanted to check with the good people here in the forum.

Back when *I* last did this (when dinosaurs roamed the earth, lol) lock-up converters had just been re-introduced but I never worked on anything that had one. There was a lot more room for error and no clutches to mangle. You just had to be careful not to drill into the turbines. But now I wonder if it's even worth the risk? Also, is the lock-up mechanism and/or internal seals in the TC subject to damage if an improper solvent is used to flush it? Is anyone here doing this? If so, what type of solvent are you using? Also, have you drilled into later model TC's? Had any clearance problems?

Personally, I'd prefer to pay someone $40 to do it for me, but I'm *so* far from anyone that can, that I'm looking for alternatives here. One thing is for sure though, that thing *has* to be flushed as it's got to be full of metal. Come to think of it, it might be worth it to just replace it with a rebuilt unit and not take the chance. Same "distance" problem exists though, and the weight could make shipping rather expensive. So what are your thoughts folks? I'm open to any comments/feedback, etc, both positive and negative. Thanks in advance.

--mike
 

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Flushing a converter is so arcane I cannot come up with a proper analogy.
Converters with lockup clutches (TCC) have so much more mechanical parts in them than does an older non lockup style converter. Trans failure = converter REBUILD !
How many of you drain out old oil from an oil filter and reuse it?? Do you flush oil filters??
Converters trap trans debris. Period. Fresh trans fluid, especially hot, is one of the best solvents available to clean trans parts, including the converter AND cooler. Moreover, the TCC clutch will be impregnated with debris, there will be a worn lining, collapsed orings or seals and worn, overheated or failed thrust washers. How are you going to clean the roller clutch in the stator assembly? Fears of imbalance are minimized by the potential trans woes introduced by re-using an old converter. Seems to me that UPS and FedEx can get anywhere in this country and the coasts are only 5 days apart, at worst. Shipping is no excuse. Quality rebuilt converters are affordable and the only choice for anyone who cares about finishing a rebuilding effort correctly.
Also, if you have that many destroyed hard parts, (4T60E) dispose of the trans cooler and install a new one.
 

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Chazmac said:
Flushing a converter is so arcane I cannot come up with a proper analogy.
Converters with lockup clutches (TCC) have so much more mechanical parts in them than does an older non lockup style converter. Trans failure = converter REBUILD !
How many of you drain out old oil from an oil filter and reuse it?? Do you flush oil filters??
Converters trap trans debris. Period. Fresh trans fluid, especially hot, is one of the best solvents available to clean trans parts, including the converter AND cooler. Moreover, the TCC clutch will be impregnated with debris, there will be a worn lining, collapsed orings or seals and worn, overheated or failed thrust washers. How are you going to clean the roller clutch in the stator assembly? Fears of imbalance are minimized by the potential trans woes introduced by re-using an old converter. Seems to me that UPS and FedEx can get anywhere in this country and the coasts are only 5 days apart, at worst. Shipping is no excuse. Quality rebuilt converters are affordable and the only choice for anyone who cares about finishing a rebuilding effort correctly.
Also, if you have that many destroyed hard parts, (4T60E) dispose of the trans cooler and install a new one.
Chazmac,

I appreciate the honest feedback - That's exactly what's needed on occasion to slap me back into reality. :) For a tad more than the cost of shipping and flushing, I can buy a reconditioned TC and put that concern behind me. And, considering the fact that I only want to do this job once, that's the best option.

You pretty much reconfirmed what I already suspected, but I wanted to hear it from someone else as well. Thanks.
 
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