Re: Can anyone point me to fluid flow schematics for 727?
[Re: BradH]
#2554122
09/24/18 04:22 PM
09/24/18 04:22 PM
|
Joined: Dec 2005
Posts: 11,551 Fulton County, PA
CMcAllister
Mr. Helpful
|
Mr. Helpful
Joined: Dec 2005
Posts: 11,551
Fulton County, PA
|
I have a '73 manual here with those charts. Of course it's all based on a stock trans. The accumulator basically acts as a cushion for the front servo to soften the 1-2 shift. On a stock unit the pressure controls in the valve body and the governor also influence that shift firmness.
If the results don't match the theory, change the theory.
|
|
|
Re: Can anyone point me to fluid flow schematics for 727?
[Re: BradH]
#2554130
09/24/18 04:29 PM
09/24/18 04:29 PM
|
Joined: Feb 2003
Posts: 10,205 Someplace you aren't
SomeCarGuy
I Live Here
|
I Live Here
Joined: Feb 2003
Posts: 10,205
Someplace you aren't
|
Try 69roadrunner.net
They had a full pdf of the 69 service manual. Full color iirc. Those manuals have the circuits in them.
You might have to register to see the forum that was in. Been a few years since I was a regular there. Seems that was how that went.
I want my fair share
|
|
|
Re: Can anyone point me to fluid flow schematics for 727?
[Re: SomeCarGuy]
#2554145
09/24/18 05:00 PM
09/24/18 05:00 PM
|
Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
|
Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
|
You want to buy the 727 bible(its out in my shop) but I forgot the author.. but I think his name is Monroe
|
|
|
Re: Can anyone point me to fluid flow schematics for 727?
[Re: BradH]
#2554178
09/24/18 06:38 PM
09/24/18 06:38 PM
|
Joined: Jan 2003
Posts: 25,785 Rio Linda, CA
John_Kunkel
Too Many Posts
|
Too Many Posts
Joined: Jan 2003
Posts: 25,785
Rio Linda, CA
|
There were two incarnations of the accumulator, '60-'70 and '71-later. On the pre-'71, line pressure acts on only two surfaces of the accumulator piston but, starting in '71, a new fluid circuit was added that is controlled by the new 1-2 Shift Control Valve.
In all configurations, the outer accumulator spring serves only to cushion the application of the front clutch and has no function on any upshift. On the 1-2 upshift the fluid pressure acting on the piston offers resistance to the piston's movement and provides a cushioning effect.
These pics are of the early piston location in both 1st (top pic) and 2nd (bottom pic); the blue fluid is line pressure.
The INTERNET, the MISinformation superhighway
|
|
|
Re: Can anyone point me to fluid flow schematics for 727?
[Re: John_Kunkel]
#2554181
09/24/18 06:45 PM
09/24/18 06:45 PM
|
Joined: Jan 2003
Posts: 25,785 Rio Linda, CA
John_Kunkel
Too Many Posts
|
Too Many Posts
Joined: Jan 2003
Posts: 25,785
Rio Linda, CA
|
These are of the late piston locations in 1st (top pic) and 2nd (bottom pic); again, blue is line pressure the green striped fluid is from the 1-2 Shift Control Valve. The fluid pressure from the 1-2 Shift Control Valve offers a variable resistance to the piston's movement and, therefore, cushions the shift in proportion to the throttle opening.
The INTERNET, the MISinformation superhighway
|
|
|
Re: Can anyone point me to fluid flow schematics for 727?
[Re: BradH]
#2554203
09/24/18 08:08 PM
09/24/18 08:08 PM
|
Joined: Dec 2005
Posts: 11,551 Fulton County, PA
CMcAllister
Mr. Helpful
|
Mr. Helpful
Joined: Dec 2005
Posts: 11,551
Fulton County, PA
|
Yes, multi years of factory manuals, Monroe's book, the ATSG book, etc., but with a manual valvebody and a race setup, much of that goes out the window.
If the results don't match the theory, change the theory.
|
|
|
Re: Can anyone point me to fluid flow schematics for 727?
[Re: BradH]
#2554215
09/24/18 08:27 PM
09/24/18 08:27 PM
|
Joined: Jan 2003
Posts: 27,421 Balt. Md
383man
Too Many Posts
|
Too Many Posts
Joined: Jan 2003
Posts: 27,421
Balt. Md
|
Also on the old and newer style line pressure is not applied to the larger spring side of the accumulator until it shifts into second gear. Ron
Last edited by 383man; 09/24/18 08:28 PM.
|
|
|
Re: Can anyone point me to fluid flow schematics for 727?
[Re: BradH]
#2554336
09/25/18 02:01 AM
09/25/18 02:01 AM
|
Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
OP
Taking time off to work on my car
|
OP
Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
|
My case is a '70, so it's the early accumulator. I read a WHOLE BUNCH of threads from here and other forums with the debate over using a spring (outer and/or inner), running no spring, running no spring plus modifying the piston to remain fixed in the "extended" config... It got me wondering if running a stiff outer spring would allow for keeping the "shock absorption" feature when applying the rear clutch, while also providing some mechanical assistance with the line pressure to reduce the time for the piston to top out into the case when the front servo is applied. Or, maybe some combination of outer spring and reduced -- not completely blocked -- piston travel. Kind of thinking out loud on this...
|
|
|
Re: Can anyone point me to fluid flow schematics for 727?
[Re: BradH]
#2554346
09/25/18 03:05 AM
09/25/18 03:05 AM
|
Joined: Jan 2003
Posts: 27,421 Balt. Md
383man
Too Many Posts
|
Too Many Posts
Joined: Jan 2003
Posts: 27,421
Balt. Md
|
Many run them different ways to their liking. Myself I run no springs and block the piston so it wont move. But I like a harsh shift all the time. Not all are like me though. Course I always run manual valve bodies in my hotrods also as I like to shift them when I want to. Ron
Last edited by 383man; 09/25/18 03:06 AM.
|
|
|
Re: Can anyone point me to fluid flow schematics for 727?
[Re: BradH]
#2554581
09/25/18 05:03 PM
09/25/18 05:03 PM
|
Joined: Jan 2003
Posts: 10,022 MN
JERICOGTX
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 10,022
MN
|
Your brain shuts down when there aren't three pedals, doesn't it? FACT.
69 GTX
68 Road Runner
|
|
|
Re: Can anyone point me to fluid flow schematics for 727?
[Re: BradH]
#2554587
09/25/18 05:11 PM
09/25/18 05:11 PM
|
Joined: Dec 2005
Posts: 11,551 Fulton County, PA
CMcAllister
Mr. Helpful
|
Mr. Helpful
Joined: Dec 2005
Posts: 11,551
Fulton County, PA
|
Blocking the accumulator up has always been a basic thing to do in a performance trans for me. That alone makes the shift "firm", I don't know if I would call it harsh. Clutch and band materials, valve body mods, clearances, lever ratio, fluid choice, etc., also contribute to shift feel.
If the results don't match the theory, change the theory.
|
|
|
Re: Can anyone point me to fluid flow schematics for 727?
[Re: BradH]
#2554625
09/25/18 06:12 PM
09/25/18 06:12 PM
|
Joined: Jan 2003
Posts: 25,785 Rio Linda, CA
John_Kunkel
Too Many Posts
|
Too Many Posts
Joined: Jan 2003
Posts: 25,785
Rio Linda, CA
|
It got me wondering if running a stiff outer spring would allow for keeping the "shock absorption" feature when applying the rear clutch, while also providing some mechanical assistance with the line pressure to reduce the time for the piston to top out into the case when the front servo is applied. Or, maybe some combination of outer spring and reduced -- not completely blocked -- piston travel.
You're thinking correctly; the stiffer the outer spring, the more cushioning for the rear clutch apply and the presence of the spring does help make a quicker (firmer) shift. The factory used a variety of outer springs, some so weak that even a geriatric like me can compress one to coil bind with two fingers. Reduced piston travel would mitigate the cushioning effect so it would be counterproductive.
The INTERNET, the MISinformation superhighway
|
|
|
Re: Can anyone point me to fluid flow schematics for 727?
[Re: John_Kunkel]
#2554661
09/25/18 06:54 PM
09/25/18 06:54 PM
|
Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
OP
Taking time off to work on my car
|
OP
Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
|
It got me wondering if running a stiff outer spring would allow for keeping the "shock absorption" feature when applying the rear clutch, while also providing some mechanical assistance with the line pressure to reduce the time for the piston to top out into the case when the front servo is applied...
You're thinking correctly... Source(s) for springs from which to select? I don't have anything in my trans parts boxes that appears to be an accumulator spring, and suspect there won't be one hiding under the valve body when I pull it, either.
|
|
|
|
|