stuck in 1st cold 3L30 , very old 1970s designed, TH180 based hyramatic box.
lets look at this path way, the load path.
does the stall test pass? in 1s and reverse? (or drive)?
do the line pressure tests, in the FSM pass (this is test 2 on all A/T )
only a dead, or grossly leaking internally, MODULATOR can stop shifts. and would be worse hot. (thinner ATF)
Where is the other end of the vacuum line, that connect to the VM goes to? VM? what is VM? vac, mod, got it.
it goes to the intake manifold the A/T has this port below,
i think the gov can be replaced xfr case off.
we can see this here.
http://www.fixkick.com/tranny/slush/slid...age_3.html
part 770 off
and 685 dismantled, ive never attempted it, but others have.
see the red line?
the red paths are marked.? and that blue path is very important.
the word LINE is the pump main line, and is LINE tests, done with gauges.
in Drive.
full line pressure arrives at DRIVE red , goes to the GOV, if packed #7 screen the gov is born dead. the governor shifts trans based on MPH speed, tail shaft RPM controlled.
The 1>2 shift valve is (controlled by GOV blue line) if dead, there will never be a 2nd gear. nor 3rd as the pressure from 1>2 valve gates to 2>?3 valve. (hydraulic logic,)
the 2nd clutch has seals (large) that sure can leak.
if the gov works, and the 1>2 valve changes to 2nd
then the 2nd line goes hot.
there are many thing on this 2nd CL (clutch ) line that can leak. cold. the accumulator is one as is the 2nd apply clutch seals.
all old seals love to leak, and can do so cold, when they warm up, they get softer and start sealing proper
this can happen at any point , of the system.
keep in mind, it might be the total combined leakage. of all seals ,(many) that makes the 1>2 fail.
fixing one leak, then later the problem returns for age on the other leaking seals, progressing to entropy as they all do.
the tests are , stall test. passes in 1st.
then line pressure, if line pressure fails, then all is lost.
if line is good, stall good, line pressure is spec. and mod is new.
then GOv screens.
the modulator (not bad or leaking) will delay shifts only on engine load, (vacuum = load)
that is its only function. and can not stop 1 to shifts. if its not leaking inside.
some mod valves fail. and leak and bleed all that precious GOV line feed, to the case, dumping the line. making it useless. this is not your failure.
![[Image: 3L.jpg]](http://www.fixkick.com/tranny/slush/slide3L30/3L.jpg)
#7 is the "screen assembly",
![[Image: governor.JPG]](http://www.fixkick.com/tranny/slush/slide3L30/governor.JPG)
![[Image: manifold%20differences.jpg]](http://www.fixkick.com/engine/8v/vacuum%20ports/images/manifold%20differences.jpg)
lets look at this path way, the load path.
does the stall test pass? in 1s and reverse? (or drive)?
do the line pressure tests, in the FSM pass (this is test 2 on all A/T )
only a dead, or grossly leaking internally, MODULATOR can stop shifts. and would be worse hot. (thinner ATF)
Where is the other end of the vacuum line, that connect to the VM goes to? VM? what is VM? vac, mod, got it.
it goes to the intake manifold the A/T has this port below,
i think the gov can be replaced xfr case off.
we can see this here.
http://www.fixkick.com/tranny/slush/slid...age_3.html
part 770 off
and 685 dismantled, ive never attempted it, but others have.
see the red line?
the red paths are marked.? and that blue path is very important.
the word LINE is the pump main line, and is LINE tests, done with gauges.
in Drive.
full line pressure arrives at DRIVE red , goes to the GOV, if packed #7 screen the gov is born dead. the governor shifts trans based on MPH speed, tail shaft RPM controlled.
The 1>2 shift valve is (controlled by GOV blue line) if dead, there will never be a 2nd gear. nor 3rd as the pressure from 1>2 valve gates to 2>?3 valve. (hydraulic logic,)
the 2nd clutch has seals (large) that sure can leak.
if the gov works, and the 1>2 valve changes to 2nd
then the 2nd line goes hot.
there are many thing on this 2nd CL (clutch ) line that can leak. cold. the accumulator is one as is the 2nd apply clutch seals.
all old seals love to leak, and can do so cold, when they warm up, they get softer and start sealing proper
this can happen at any point , of the system.
keep in mind, it might be the total combined leakage. of all seals ,(many) that makes the 1>2 fail.
fixing one leak, then later the problem returns for age on the other leaking seals, progressing to entropy as they all do.
the tests are , stall test. passes in 1st.
then line pressure, if line pressure fails, then all is lost.
if line is good, stall good, line pressure is spec. and mod is new.
then GOv screens.
the modulator (not bad or leaking) will delay shifts only on engine load, (vacuum = load)
that is its only function. and can not stop 1 to shifts. if its not leaking inside.
some mod valves fail. and leak and bleed all that precious GOV line feed, to the case, dumping the line. making it useless. this is not your failure.
#7 is the "screen assembly",
http://www.fixkick.com