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New Member
- Joined
- Sep 1, 2014
Hello everyone, I understand this is the place to come for 200 4R problems. I have a 78 corvette with a 200 4R and it has no second gear. It used too, but recently lost it. I can get it to skip second and go to third and it works fine 3-4, lockup works, 4-3 downshift works, just no second. Its as if it is in neutral when it should be in second.
Everything I've read points to a band or servo problem. So i pulled the valve body, air tested the servo. I could get the servo to apply with air and could see the band applying also. I could turn the driveshaft while applying air but wasn't sure if that was normal due to the air gun not getting a perfect seal on the port.
I then pulled the servo and just reinstalled the pin and pushed on it with a prybar, I could also see the band apply when pushing on the pin with a prybar. I reinstalled the servo and cover minus the sealing o ring and pushed on the outer cover with the prybar and noticed again that the band was applying. I had approximately 1/8 inch travel on the cover.
What I am not sure about is if the band is applying enough. Could it still be slipping? From what little i can see of the band with the pan off, I can see friction material and don't see any burn marks on the drum. The fluid is also not burnt.
This where I am at now, not sure where to go next. Could there be anything else besides the servo or band?
Any help would be greatly appreciated
Brian
Everything I've read points to a band or servo problem. So i pulled the valve body, air tested the servo. I could get the servo to apply with air and could see the band applying also. I could turn the driveshaft while applying air but wasn't sure if that was normal due to the air gun not getting a perfect seal on the port.
I then pulled the servo and just reinstalled the pin and pushed on it with a prybar, I could also see the band apply when pushing on the pin with a prybar. I reinstalled the servo and cover minus the sealing o ring and pushed on the outer cover with the prybar and noticed again that the band was applying. I had approximately 1/8 inch travel on the cover.
What I am not sure about is if the band is applying enough. Could it still be slipping? From what little i can see of the band with the pan off, I can see friction material and don't see any burn marks on the drum. The fluid is also not burnt.
This where I am at now, not sure where to go next. Could there be anything else besides the servo or band?
Any help would be greatly appreciated
Brian