700R4 no Shift
Thread Starter
Teching In
Joined: Apr 2025
Posts: 17
Likes: 4
700R4 no Shift I've been a trans tech for many years and seen a few weird
ones and fixed them but this one has got me.
700r4 with Aux vb or 4L60, not sure of year cause # corroded
away valve body was rusted so i used a clean 91 4l60 that was
good and looked identical.
Did a normal mild Perf build with TG 700 2&3 kit. Used TG 700P
plate. Thorough air pressure test checked nice . Clutches
and 2nd and 4th on band were nice.
Started by changing Gov.Then pulled VB and servo. Found
nothing.
Yes, TV cable is perfect.
Pulled unit and checked band adjustment and servo & anchor pin.
Paid close attention to blocked holes in plate.
1 weird thing is that with a gauge on 2nd port. the wheels
start turning maybe 5 mph and bingo, Pressure jumps to 75 and
increases with throttle but NO SHIFT
Any Ideas??? Thanks for any replies. RJ
ones and fixed them but this one has got me.
700r4 with Aux vb or 4L60, not sure of year cause # corroded
away valve body was rusted so i used a clean 91 4l60 that was
good and looked identical.
Did a normal mild Perf build with TG 700 2&3 kit. Used TG 700P
plate. Thorough air pressure test checked nice . Clutches
and 2nd and 4th on band were nice.
Started by changing Gov.Then pulled VB and servo. Found
nothing.
Yes, TV cable is perfect.
Pulled unit and checked band adjustment and servo & anchor pin.
Paid close attention to blocked holes in plate.
1 weird thing is that with a gauge on 2nd port. the wheels
start turning maybe 5 mph and bingo, Pressure jumps to 75 and
increases with throttle but NO SHIFT
Any Ideas??? Thanks for any replies. RJ
LS1Tech Sponsor
Joined: Mar 2023
Posts: 1,824
Likes: 1,162
From: BERWICK PA
Hard one , seems you have covered bases. Let see if pressure is going to the servo when that pressure says its in second. Will need 2-3 people. one in car obviously . Another to watch gage unless you can mount so you can see it.
Use a prybar and push in on he servo cap. Then while holding cap in place in gear then accelerate till the 2nd pressure comes up . When it does .the servo cover should push back. Of it does you have proven oil is going to the servo when the 1-2 shift pressure goes up. so its still a band issue. If not then you know line is either being dumped at servo or feed to servo is blocked.
I know seems like a simplistic test . But with you seeing the gauge showing that is the next thing to find out. Is the oil really going to the servo.
Use a prybar and push in on he servo cap. Then while holding cap in place in gear then accelerate till the 2nd pressure comes up . When it does .the servo cover should push back. Of it does you have proven oil is going to the servo when the 1-2 shift pressure goes up. so its still a band issue. If not then you know line is either being dumped at servo or feed to servo is blocked.
I know seems like a simplistic test . But with you seeing the gauge showing that is the next thing to find out. Is the oil really going to the servo.
__________________
Frank formerly of Performabuilt, Now just me, What can I build for you today? Call or message me. Click sig pic for my facebook
Frank formerly of Performabuilt, Now just me, What can I build for you today? Call or message me. Click sig pic for my facebook
TECH Enthusiast
Joined: Jan 2019
Posts: 677
Likes: 490
From: Roxana, IL
They will leak air from around the shift/tv valve sleeve when doing it that way.
During a build, I air test with 40psi through a custom built air test plate to make sure all clutches/band apply.
First thing to do is double check that the 700P plate has the correct plugs for the Type "A" or "B" valve body. It is a universal plate for both non-aux & auxiliary type transmissions.
Seems like I left a slug out once and had that same issue....
Here is a new set of 700-P instructions.
During a build, I air test with 40psi through a custom built air test plate to make sure all clutches/band apply.
- Fwd.
- Rev.
- O/R
- 3-4
- L/R
- P/R
- 2nd apply
- 3rd release
- 4th apply
First thing to do is double check that the 700P plate has the correct plugs for the Type "A" or "B" valve body. It is a universal plate for both non-aux & auxiliary type transmissions.
Seems like I left a slug out once and had that same issue....
Here is a new set of 700-P instructions.
Thread Starter
Teching In
Joined: Apr 2025
Posts: 17
Likes: 4
I did notice a strange noise while under car while running . It sounded somewhat like a stripped spline . So I pulled unit
, disassembled and found nothing.
Also/
Tranzman, why such low air pressure while testing. Do you do it dry or with oil?
Checked plate again. seems good.
, disassembled and found nothing.
Also/
Tranzman, why such low air pressure while testing. Do you do it dry or with oil?
Checked plate again. seems good.
TECH Enthusiast
Joined: Jan 2019
Posts: 677
Likes: 490
From: Roxana, IL
I soak my clutches and let them drip for about 15-30 minutes. I also use a 50-50 ATF and STP to lube lip seals/drums/sealing rings.
So I guess you can say it's wet. I don't add more fluids during the air test.
Why so low? Because if it will apply at 40psi. Line pressure won't be an issue. Lower pressure allows a leak to show as bubbles rather than a spew of fluid. Most cases it is easier to find that way. The 60-80psi is because the 4th shift valve won't move with 40psi.
Similar to testing a 4L60E 1-2 shift valve for movement.
So I guess you can say it's wet. I don't add more fluids during the air test.
Why so low? Because if it will apply at 40psi. Line pressure won't be an issue. Lower pressure allows a leak to show as bubbles rather than a spew of fluid. Most cases it is easier to find that way. The 60-80psi is because the 4th shift valve won't move with 40psi.
Similar to testing a 4L60E 1-2 shift valve for movement.
TECH Junkie
Joined: May 2012
Posts: 3,052
Likes: 716
From: Poplarville, MS
I did notice a strange noise while under car while running . It sounded somewhat like a stripped spline . So I pulled unit
, disassembled and found nothing.
Also/
Tranzman, why such low air pressure while testing. Do you do it dry or with oil?
Checked plate again. seems good.
, disassembled and found nothing.
Also/
Tranzman, why such low air pressure while testing. Do you do it dry or with oil?
Checked plate again. seems good.
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Thread Starter
Teching In
Joined: Apr 2025
Posts: 17
Likes: 4
I want to that you guys for reply's. Turned out VB was kitted before and did not play nice with changes I made.
Unit back in and shifting. Still needs further road test and manual linkage work. Thanks again. RJ
Unit back in and shifting. Still needs further road test and manual linkage work. Thanks again. RJ