re-using a torque converter

[2deuce]

I have this M1028 that has a cooked transmission. I bought it this way from the Gov't. It was only used as a campground truck. So I'm thinking someone abused it in possibly 1 episode. The fluid was good in the transfer case. It has 37k miles on it that probably are original.
I can't find a new torque converter for 1) a reasonable price, and 2) that won't take weeks to be delivered. What do you guys think about draining my old one, and flushing it as best as I can, and re-using it on a used transmission I had in my spares pile. This work is all done on my back so I'm not set up to do this work often. Anyone done this?
Thanks

 

[cwc]

Yes, I've done it on "rat rod" projects where expectations are not necessarily real high. I would be looking to see if the filter is intact, the filtered side of the transmission is free of debris, siphon out the fluid from the TC and see if stuff settles out or is visible in it. Also consider the torque converter seal area...

Maybe the torque converter is the problem with the transmission, especially if it's bad in all gears? It would be interesting to break it down and see if smoked clutches etc. match the symptoms.

 

[patracy]

Transfercase fluid doesn't flow through the tranmission at all. You'll never be able to get all the fluid and contaminates out of the converter, just due to it's shape. They have to be cut to be refurbished. Most likely there's nothing in the TQ that is wrong. Just a lot of stuff you don't want getting back into a newly rebuilt transmission. $190 and there in a week. Cheap insurance:

https://www.amazon.com/TORCO-TH400-Chevy-Turbo-400/dp/B07L2KR5XB

 

[2deuce]

I don't know if it was bad in all gears. It wouldn't move. When put in drive it acted like I already removed the transmission. The transmission is out at this time. The drained fluid smells burnt to the n'th degree. What I was told from the gov't shop where I picked it up was that it's operator has a way to destroy whatever he got his hands on. So I expected abuse and not normal wear.

If I was putting a newly rebuilt transmission back in, I would want a new converter for sure, but this os a used tranny and untested. I got it in a botched 24v to 12 v conversion M1009 where the flex plate became ruined and they bailed on the truck. I bailed on it too when I noticed the roof was rusted out at the windshield. I had gotten it back in the day when you could get a M1009 needing work for $500. Thanks for the link on the new rebuilt converter, but it doesn't say what bolt pattern it is, what the spline count is, and I bet it is for a gas engine with a higher stall. That's the problem I'm running into, once diesel is mentioned, availability goes away. I came close on a few, but bolt pattern or spline count was off. My used transmission is a 27 spline, 11.5, 6 bolt flex plate.

 

[GopherHill]

I have reused a converter from a bad transmission by flushing well and using an external filter on the return line from the transmission cooler.
If you are poor, roll the dice.

 

[patracy]

If I was putting a newly rebuilt transmission back in, I would want a new converter for sure, but this os a used tranny and untested. I got it in a botched 24v to 12 v conversion M1009 where the flex plate became ruined and they bailed on the truck. I bailed on it too when I noticed the roof was rusted out at the windshield. I had gotten it back in the day when you could get a M1009 needing work for $500. Thanks for the link on the new rebuilt converter, but it doesn't say what bolt pattern it is, what the spline count is, and I bet it is for a gas engine with a higher stall. That's the problem I'm running into, once diesel is mentioned, availability goes away. I came close on a few, but bolt pattern or spline count was off. My used transmission is a 27 spline, 11.5, 6 bolt flex plate.

Well, it's your choice. A TQ from a known bad transmission almost certainly has metal/friction/contanimantes in it. But you're rolling the dice with a maybe transmission.

The link I shared does specify the details you're looking for. 11.5". Just specify you want a 6 pad converter (photo is of a 6). But your transmission will have a 30 spline input for the TQ. And the output should be a 32 spline. 27 spline shafts were the output shaft spline count on the TH350 and 700R4's. (There were some TH400 aftermarket outputs with 27 splines to aid in swapping in TH400's, but this wouldn't be factory) It's also mentioned to be 1400-1600 stall. A little higher than the stock diesel one. But useable still. Sounds like you can spec them however you like from them as well.

 

[GunnyM1009]

I'm no expert but aren't the TH400 transmissions in cucvs 30 spline to the torque converter. Like this

https://www.autozone.com/drivetrain/transmission-torque-converter/p/tc-remanufacturing-automatic-transmission-torque-converter-b3/263397_0_0

Edit- @patracy beat me to it

 

[Keith_J]

Filtered oil circulates in the TC, no locking clutch so they don't get trash in the Torrington bearings or sprag clutch. Reuse of a THM400 converter is less risky than any other.

 

[country]

we have rebuilt torque converters for the TH400 in stock for $69



HM-212 | Torque Converter GM 3 Speed TH 400 Transmission HMMWV
Torque Converter Transmission Turbo 400. Fits HMMWV
NSN #: 2520-01-164-7234
Part #: 8629917, PR4608M
$69.00

 

[gringeltaube]

I can't find a new torque converter for 1) a reasonable price....

Contact @gimpyrobb, he has those TC (NIB) and I'm sure he would sell you one for a very reasonable price.

 

[royalflush55]

I would rather use the TC from the used transmission you are installing than the cooked one if trying to save a buck.

 

[2deuce]

I've decided to re-use the one I have. If that turns out to be a bad idea, I know where to get a rebuilt one. As in Dirty Harry... I'm Feeling Lucky!
Thanks to all.

 

[2deuce]

Royal, I agree, but it got mixed up with a couple of bad ones, and I don't know which one it is. I screwed up.

 

[cucvrus]

Really a $69. rebuilt torque converter and you are going to risk the whole job? Spend the coin and move on with confidence and not doubt. There is more than $69. worth of ATF in that transmission. Any job worth doing is worth doing right the first time. Money is a tool. Use it wisely. Good Luck.

 

[MarkM]

You guys are forgetting that IF garbage went through the torque converter then it also went through the transmission cooler and could have deposited garbage in there. If it were me I would check the filter as already recommended as well as the pan.

If the filter is reasonable I would strain the fluid in the torque converter through a rag and the same as you flush the cooler. If the rags are clean of debris a good flushing should be sufficient. The tranny filter is your last line of defense. Just my two cents.

Mark

 

[2deuce]

I didn't think about flushing the cooler. I could blow it out, but how do you flush it? Thanks

 

[MarkM]

I would pickup a cheap gallon of Dex 3 and using a drill driven transfer pump just push the fluid through the cooler.

If you make up an extension hose to the gallon container you can filter the return fluid. Use a doubled up rag or cheese cloth as a makeshift filter. This way you can inspect the fluid for any trash and the cost was just a gal of Dex 3.

Mark