Tataocb
TYF Newbie
I have rebuilt about 10 of these transmissions this year as a "side hustle" of which 8 have worked successfully after rebuild. There are two that I am working on right now that I need some assistance with. When I rebuilt the first 4-5 transmissions I used the Transmission Bench rebuild tutorial as well as Nick Transmissions videos on YouTube to learn how to rebuild them. Both of these transmissions were not originally in the car they ended up in. They were cores left from the other rebuilds. For both rebuilds I used a gasket/seals kit, replaced frictions and steels, molded pistons, aluminum accumulator pistons, new solenoids, band, filter and reused the wiring harness. In both cases I checked the input drum for leaks around the shaft and both were good. I also checked the separator plate and repaired any check ball areas where the hole had been enlarged. All clearances were checked. The 3-4 clutch pack was at 0.060. Now for the issues.
Transmission A - original issue was loss of 3-4 gear
After installing it had two issues:
A. Reverse felt like it was difficult to engage, like the calipers were stuck or the vehicle brakes were applied when trying to use reverse.
B. 2-3 flare shift.
I replaced the servo with another one I had and took it for a drive but the 2-3 flare shift was still there.
After that I decided to remove the transmission and open it back up. I tested the drum assembly through the pump (feeding compressed air through the pump holes) and found that reverse was not engaging. I then found one of the sealing rings on the pump was flattened so I replaced all sealing rings on the pump and the input shaft. I tested the drum assembly with the pump again and reverse was now engaging.
I put the drum assembly back in the transmission and checked to make sure it would spin with the band in place (to check clearance) and it did. I reassembled the transmission and bought a test plate to check through the valve body and all the clutch packs applied correctly. I could also feel the band engaging and disengaging when air was applied and removed through those circuits.
Is there anything else I can check for the flare shift? Should I perhaps go with a corvette servo?
Transmission B - original issue was loss of 3-4 gear
After installing the transmission it worked well for 2 weeks and then it lost 3rd and 4th. The transmission was removed. I checked for leaks around the input shaft again and did not find any. I checked the drum assembly through the pump and everything engaged correctly. I replaced the 3-4 clutch pack and reassembled. I did an air check through the pump and then again using the test plate after reassembly and everything engaged fine. I finished reassembling the transmission, installed it, took it for a drive and still no 3rd or 4th gear.
This was not the transmission that was originally in this car. The one it had before had a rattling noise, but shifted through all gears so I do not think the issue is in the vehicle's electrical system. I am wondering if the issue might be with the harness that goes inside the transmission? Both shift solenoids were replaced with new ones. Otherwise, if the transmission air checked fine, why would it lose 3rd and 4th once installed?
Any help would be greatly appreciated.
Transmission A - original issue was loss of 3-4 gear
After installing it had two issues:
A. Reverse felt like it was difficult to engage, like the calipers were stuck or the vehicle brakes were applied when trying to use reverse.
B. 2-3 flare shift.
I replaced the servo with another one I had and took it for a drive but the 2-3 flare shift was still there.
After that I decided to remove the transmission and open it back up. I tested the drum assembly through the pump (feeding compressed air through the pump holes) and found that reverse was not engaging. I then found one of the sealing rings on the pump was flattened so I replaced all sealing rings on the pump and the input shaft. I tested the drum assembly with the pump again and reverse was now engaging.
I put the drum assembly back in the transmission and checked to make sure it would spin with the band in place (to check clearance) and it did. I reassembled the transmission and bought a test plate to check through the valve body and all the clutch packs applied correctly. I could also feel the band engaging and disengaging when air was applied and removed through those circuits.
Is there anything else I can check for the flare shift? Should I perhaps go with a corvette servo?
Transmission B - original issue was loss of 3-4 gear
After installing the transmission it worked well for 2 weeks and then it lost 3rd and 4th. The transmission was removed. I checked for leaks around the input shaft again and did not find any. I checked the drum assembly through the pump and everything engaged correctly. I replaced the 3-4 clutch pack and reassembled. I did an air check through the pump and then again using the test plate after reassembly and everything engaged fine. I finished reassembling the transmission, installed it, took it for a drive and still no 3rd or 4th gear.
This was not the transmission that was originally in this car. The one it had before had a rattling noise, but shifted through all gears so I do not think the issue is in the vehicle's electrical system. I am wondering if the issue might be with the harness that goes inside the transmission? Both shift solenoids were replaced with new ones. Otherwise, if the transmission air checked fine, why would it lose 3rd and 4th once installed?
Any help would be greatly appreciated.
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