C6 torque converter

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Sep 21, 2016 | 05:49 PM

460_Ranger

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C6 torque converter

Hey guys, new around here. Just finished putting a fresh 460 backed by a (1977) c6 in my '68 ranger and now I'm having (what I believe is) transmission problems. The truck will idle and rev properly in gear but as soon as I put it in drive or reverse the RPM's drop and it dies. I jacked the back end up and put it in both drive and reverse and the tire's spin, but if I try and apply the brake to stop them the truck will die. My suspicion is that the torque converter is locked up all the time. I have managed to get it in gear and give it gas and it'll drive and shift fine, until I come to a stop. My question, what would cause the converter to do this? It's the same transmission and converter that I pulled out a month ago and I never had any issues before

Thanks,
Derek

Sep 21, 2016 | 10:30 PM

jk080

Transmission Rebuilder

Joined: Jul 2008

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From: North Georgia

I have never seen a C6 converter stall the engine, it's not a lockup style converter so if it's not severely damaged then it would not be likely.

Only thing converter related issue I could see on the your transmission is that maybe the stock stall speed of the converter is too low for your new engine to idle, you could get a higher stall speed converter.

I think engine timing, vacuum problems and carb adjustments will be more likely the cause rather than the transmission.

Hope that helps!

Sep 22, 2016 | 10:22 PM

460_Ranger

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Thanks for the response jk080.

What kind of symptoms would I encounter if the converter wasn't seated properly? My suspicion at this point is my motor can't idle low enough while the transmission is in gear and that's what's stalling the motor.

If my TC has too low of a stall speed would that cause issues at an idle while in gear? My cam recommends a 2000rpm stall converter and I have suspicions I have a stock TC. From my brief reading online stock converters for these transmissions is somewhere 1,400-1,800rpm. Is that a significant enough difference to cause problems?

I am completely new to automatic transmission's and just trying to learn my way

edit: I did manage to get enough time today to check vaccum and it sat at 15" at 1000-1100rpm. Tomorrow I hope to check timing and fuel mixture to hopefully get a proper idle, not the 1000rpm it's currently at

Thanks,
Derek

Sep 29, 2016 | 09:21 AM

Braggs

Senior User

Joined: May 2016

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I have had problems with the engine dying/stalling when putting it in gear. The issue is likely a vacuum leak. Get you a can of carb cleaner and spray it around the engine compartment with the engine running. When the engine RPMs dip/stall, you've found your problem area.

Pro tip: replace all your old, crusty, dry, cracked vacuum hoses. If they make your hand black, it's time to replace.

Sep 29, 2016 | 07:09 PM

FORDF250HDXLT

Fleet Owner

Joined: Jul 2006

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From: Mi'kma'ki

on my t-birds old carb,it was doing the same thing.i felt all around trying to find a vac leak.a rear rubber plug fell apart as i touched it lightly.replaced it,and she idled smooth.
still had a stumble off idle (no one plumbed in a filter!) and it was a bit too small,so i then upsized the carb anyway.but point being,feel around the carb plugs and hoses.you might be surprised what you'll find in just 30 seconds or less.