Torque Converter Advice

[PbFut]

I have mostly owned manuels so have limiter knowledge of torque converters. After some fooling with fluid changes, it is clear to me that more is going on. Shifting and take offs are still very good, but I have got serious heat issues making me think it is time for new converter.
1972 GMC C25/2500. Mostly stock 350 motor and a thm350 trans allowing for a low stall speed. Current converter appears original.
Would the recomendation be for a basic $125 rebuilt, a $250 new low end B&M or something else?

[PbFut]

No opinions?

[72c20customcamper]

Best bet have local shop look into your problem may be more than just the converter . The standard rebuilt would be good for a stock set up if that’s all that’s wrong but most likely something else would have caused the converter to fail

[leftybass209]

I just had a TH350 rebuilt and installed completely for 2k with a new converter. I tried to crutch this thing with seal changes, new gov, modulator, etc. but it eventually gave up coming home from work. It was just a worn out 51 year old trans.

If it's overheating after a fluid and filter change, then the system would probably need to be flushed, and/or have the radiator portion of the cooler checked for proper flow. I'd weigh the cost and time of various repairs vs a rebuild.

I wasted around 250 bucks plus a few rare days off of time with my various trans issues.

[Accelo]

Some light vehicles, like the Vega, had 350 transmissions that came without any cooler or even the lines to attach one.
Do you have a gauge or any hard measurements to quantify "overheating"?

I have never seen a stock converter cause overheating. Not that's it's not possible, just rare.
Cheers

[leftybass209]

Originally Posted by Accelo

Some light vehicles like the Vega had 350 transmission without any cooler or even the lines to attach one.
Do you have a gauge or any hard measurements to quantify "overheating"?

General curb weight of a c20 is 3,990ish lbs

A Vega is 2,270ish lbs

The difference is around 1,720lbs, which seems out of the realistic range of th350 comparability given the applications are wildly different.

[72c20customcamper]

I had mine done two years ago I pulled it had it rebuilt they charged me 1200 with the converter . They gave me a couple cans of this to flush the lines and the cooler so I would have the 12 month 12k mile warranty.

[72c20customcamper]

This is with a large auxiliary cooler the temp probe is in the line coming out of the trans to the rad cooler . This was pulling my 68 on the car trailer at 65 on interstate 81 . It climbed to 185 climbing the Pocono mountains on 81 but came right down

This is my 72 with a 350 with a TH 350. 4.11rear

[PbFut]

So a final follow up. I replaced the TC with a new B&M Touque Master model 20400. $260 @ Summit. The result lowered Temps 40 degrees. I then added an aux cooler in front of the radiator cooler using a Hayden cooler and inexpensive 8" fan from amazon. All in with with fittings and hose and relay about 100 bucks.
I would easily hit 240 250 on a 4 mile climb up a grade close to home and it would also stress coolant Temps. Now I run at 160 to 180 trany temps. Running up the grade with ac on the tranny cooler kicks on at 185 and I did not go over 200. The tranny probably has a bit of slip but if the Temps hold at these levels, I will call this issue solved. These Temps were during a local heatwave at 105 ambient air Temps and ac running. Champion 4core radiator with elec fans. Coolant at or below mid point of factory guage. Probably 175 to 190. Hopefully this info will help someone having overheat issues and not spend a grand or 2 on a tranny when 250 bucks could cure their problem.
For good measure, with the drive shaft out I had a local shop swap out the ujoints and a very worn center support. I had zero vibration but the support was trashed and the front ujount stiff.

[Bigdav160]

Internal endplay of the converter should be less than .030"

They'll still work as wear increases the endplay toward .100". The result is lots of heat.

Glad you solved your issue.