c6 trans
Moderator
Joined: Jan 2001
Posts: 56,995
Likes: 2,741
From: Virginia
Use Dexron transmission fluid. You can use any of the Dexrons from 3 to 6.
I have never had one act that way. One thing I would check, make sure the kickdown lever and linkage is free and in it's home position. It originally went to the carb linkage. I have had them act weird when this linkage was hung up and activated all the time.
P.S. When you take off, you are only getting one shift?
I have never had one act that way. One thing I would check, make sure the kickdown lever and linkage is free and in it's home position. It originally went to the carb linkage. I have had them act weird when this linkage was hung up and activated all the time.
P.S. When you take off, you are only getting one shift?
Cargo Master
Joined: Aug 2007
Posts: 2,561
Likes: 69
From: New Zealand
Often this can be remedied by taking the vehicle to a quiet road (or jack the rear wheels up onto axle stands) & drive in reverse for a minute or so.....this flushes the governor with trans fluid.
I've corrected two C6's I owned, with your problem, this way.
Cargo Master
Joined: Aug 2007
Posts: 2,561
Likes: 69
From: New Zealand
Yes.....both times I had the problem it was downshifting that was affected, upshifts were still ok.
But good brisk driving in reverse ( I went about a 1/2 mile) flushes fluid into the tailshaft housing, where the governor is located.
But good brisk driving in reverse ( I went about a 1/2 mile) flushes fluid into the tailshaft housing, where the governor is located.
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Logistics Pro
Joined: Jun 2017
Posts: 3,978
Likes: 514
From: Edmond, OK
I'd be all over that backwards driving. You can pretend you're driving a tow truck! 
Really though, I just had to get the C6 in my 86 F250 rebuilt. I adjusted the intermediate band and replaced the vacuum modulator and it never shifted right until after the rebuild. I hope you can get your's shifting right.
Really though, I just had to get the C6 in my 86 F250 rebuilt. I adjusted the intermediate band and replaced the vacuum modulator and it never shifted right until after the rebuild. I hope you can get your's shifting right.
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