727 Transmission : not going back to 1st gear after a stop

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Nico383

Nico383

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Hi gents,

When I make a stop at a red light for exemple, if my transmission is set to Drive, when I drive again at green light I'm pretty sure the transmission doesn't come back to the 1st gear and stays in 3rd gear.

Would you know what is the reason of this weird behavior?

Thanks,

Nico.
 
What kind of condition is this thing in?

Fluid bright red, or does it smell burned?

There are a few reasons they can do this out of the blue like a valve stuck in the valve body. a stuck governor, pressures being way off or even worn out and friction welded internals.
 
Fluid is bright red bud I didn't drive a lot since the last drain (1 month ago)
 
Nico383 said:
Fluid is bright red bud I didn't drive a lot since the last drain (1 month ago)
Click to expand...

Fishy68 is more versed in diagnostic on these things, and he will see this.
He actually does this, and I used to.
The more I think about it the more it sounds like a mechanical failure, but I can only go on what information is available.
It could also be a collapsed valve spring (as in broken) or simply a dirty valve body even.

If it were me, I'd pull the pan and see whats in there (if anything out of the norm)
If it looks fine in there then I'd pull the valve body and inspect it real close.
I don't think air checking the clutches and servo's while the valve body is out would tell us anything we need to know.

Post pics too if you can.

Don't overlook the many many videos online also.

It would also be good to know what it does when you take off and it feels like it's in third and you manually pull it down into lower gears.
Does it feel like it downshifts, or stay the same?
 
Generally this is caused from the governor pressure being too high (if it doesn't drop below 1-1/2 psi at a stop it won't downshift) because the governor is sticking. What did the fluid look like when you drained it last month?
 
fishy68 said:
Generally this is caused from the governor pressure being too high (if it doesn't drop below 1-1/2 psi at a stop it won't downshift) because the governor is sticking. What did the fluid look like when you drained it last month?
Click to expand...

That's exactly why I wanted to refer that one to you.
I wasn't sure (couldn't remember) about the governor if the car was stopped.
 
Check that your throttle pressure rod is not too long and pushing too hard all the time too. Easy to verify and worth looking at no matter what.
Tom.
 
Hook up a pressure gauge to the gov port and find out real quick.
 
Hi all,

Thank you for all your information. When I drained trans fluid one month ago, the tran fluid was bright red.
One thing that may be interesting : I drove few miles with a kick down not in place (stuck against the fire wall electrical connector). Can it have an impact on the governor's health?
Since then I tryed to set up the kickdown correctly but trans is not downgrading when carb is WOT...

Thanks,

Nico
 
Nico383 said:
Hi all,

Thank you for all your information. When I drained trans fluid one month ago, the tran fluid was bright red.
One thing that may be interesting : I drove few miles with a kick down not in place (stuck against the fire wall electrical connector). Can it have an impact on the governor's health?
Since then I tryed to set up the kickdown correctly but trans is not downgrading when carb is WOT...

Thanks,

Nico
Click to expand...

It has no direct effect on the governors health but if improperly adjusted it now only will not kick down when you stomp on it but the shifts may be early and soft which will burn up a torqueflite. Get the throttle pressure linkage (kickdown as you call it) fixed right as priority one no matter what it takes.
 
Hi Gents,

I found this Chrysler video and had been finally able to set up properly the pressure linkage. Many thanks for your advice!

[ame="https://www.youtube.com/watch?v=KsfI9cFFPpg"]71 02 Shift Quality and Linkage Adjustment - YouTube[/ame]

Nico
 
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