# GTO transmission fluid



## 66 GTO (Sep 14, 2007)

I have 66 gto with a 69 gto 400 motor and a 4 speed manual transmission, I went to change the tanny fluid today and on the passenger side of the transmission is what i think is the filler bolt, but i can not find the drain bolt. could someone please tell me where the drian bolt is?


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## macgto7004 (Jul 22, 2007)

Hey 66 GTO,
As far as I know, the Muncie M20 and M21s did not have a drain plug. Early M22s didn't either. I have heard that somewhere along the line, the M22 got a drain plug in 1970. 
I think the M21s have a boss cast into the case that can be drilled and tapped for a drain plug, but they never left the factory with one.

You will probably have to get a little pump and feed a hose into the fill hole and take the lube out. then you can refill it in the reverse.

I hope this helped, and anyone, please correct me if I am wrong.

Russ


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## 66 GTO (Sep 14, 2007)

Ok, well thats how ill change the oil, thanks for the help Russ.


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## Dave389 (Aug 4, 2015)

Hi 66 GTO - 
I saw your post regarding the transmission fluid change. I am also trying to change the transmission fluid on my car - 1965 389 four speed manual. Were you able to resolve how to change the fluid? If so, PLEASE let me know the procedure.
Thanks! 
David


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## Pinion head (Jan 3, 2015)

remove the filler plug on the pass side of the muncie case then insert clear plastic filler hose from a suction gun. I made one out of an old full size cartridge grease gun. the lower drain plug came std when the "661" Muncie cases were phased in mid '70 production.


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