paulbaumgartner Posted August 9, 2005 Report Share Posted August 9, 2005 I have a 93 STS with the 295hp 4.6L. It has the 4T80 FV4 transmission with 120k miles. The car only had second gear (and reverse) when I bought it. I am trying to fix it up for one of my kids. I replaced the shift solenoids and filter (GM pn# 24211355 valve kit). It now shifts into all gears however, 4th is slipping under part to moderate throttle. Under light throttle I can feel it is coupled to the wheels and does work, sort of... My recollection of the initial test drive after solenoid replacement was it worked properly. But I am not real sure on that detail because it was a short drive. The second test drive I had the car at highway speeds for a longer period. I think a piece of debris in the valve body may be the problem. Please, if you have any ideas on this your comments would be appreciated. I removed the valve body assembly from the transmission. Then I separated the solenoid section from the valve body assembly on a bench when I replaced the solenoids. I soon realized that it was not necessary to disassemble the valve body and my heart rate went skyrocketing up when I saw the four little check valve balls starring back at me from the valve body assembly. I did not disturb their positions and took great care to make sure it went back together properly. The original transmission fluid looked to have maybe 50k miles without excessive debris in the fluid or pan. Also there was no indication of excessive heating or burning. All electronics are working properly and there are no TCS codes being sent to the PCM. When I had the pan off and all assemblies in place, I ran the onboard tests available from the inst panel and verified solenoid operation. I am really not looking forward to dropping the pan again unless I have some expert advise on a few specifics. HELP!!!! Link to comment Share on other sites More sharing options...
canadian95sts Posted August 9, 2005 Report Share Posted August 9, 2005 paulbaumgartner, check out this post i found in the archives, it sounds exactly like the problems you are experiencing, and has some helpful info on how to troubleshoot . 4th gear slippage Matt P.S. Make sure you read both pages A good friend will come and bail you out of jail...BUT, a true friend will be sitting next to you saying, "darn...that was fun!" www.madd.ca Link to comment Share on other sites More sharing options...
paulbaumgartner Posted August 9, 2005 Author Report Share Posted August 9, 2005 Canadian95sts Thanks, that was interesting. Particularly about the eight check balls instead of the four I counted. I am going to contact that member for specifics. Thanks so much for the research. Link to comment Share on other sites More sharing options...
Scotty Posted August 9, 2005 Report Share Posted August 9, 2005 Check this post also, it shows where the balls go Mike http://caddyinfo.ipbhost.com/index.php?sho...&hl=check+balls Link to comment Share on other sites More sharing options...
Oldgamer Posted August 9, 2005 Report Share Posted August 9, 2005 Other four balls you'll see if you remove accumulator assembly. Link to comment Share on other sites More sharing options...
paulbaumgartner Posted August 9, 2005 Author Report Share Posted August 9, 2005 Guys,This is great stuff.... Thanks so much for all the feedback I hope I dont have to get into the accumulator. One of the posted photos had a very usefull diagram that shows the hydro circuts numbered over the channels, what a wealth of info. I bought a cd a while back but it didn't contain that much detailed info on the mechanics of the 4t80. Thanks again Paul Link to comment Share on other sites More sharing options...
paulbaumgartner Posted August 9, 2005 Author Report Share Posted August 9, 2005 Also, in the arcives, there was mention of using shim stock to hold the lo/reverse band during reinstallation of the valve body assembly. Did I possibly miss something when I reassembled.... One other detail I forgot to mention. The A solenoid seemed to be much warmer to touch than the B solenoid. I noticed this during the testing when I had the pan off. Both solenoids were tested for approximately the same time and duty cycles. The voltages appeared correct as well. Paul Link to comment Share on other sites More sharing options...
Scotty Posted August 9, 2005 Report Share Posted August 9, 2005 Guys,This is great stuff.... Thanks so much for all the feedback I hope I dont have to get into the accumulator. One of the posted photos had a very usefull diagram that shows the hydro circuts numbered over the channels, what a wealth of info. I bought a cd a while back but it didn't contain that much detailed info on the mechanics of the 4t80. Thanks again Paul Use White Grease to hold the balls in place, Mike Link to comment Share on other sites More sharing options...
Oldgamer Posted August 9, 2005 Report Share Posted August 9, 2005 Also, in the arcives, there was mention of using shim stock to hold the lo/reverse band during reinstallation of the valve body assembly. Did I possibly miss something when I reassembled.... One other detail I forgot to mention. The A solenoid seemed to be much warmer to touch than the B solenoid. I noticed this during the testing when I had the pan off. Both solenoids were tested for approximately the same time and duty cycles. The voltages appeared correct as well. Paul You didn't use shim, but that's not a problem cause you have reverse, so it means that band was in right position when you installed control plate back. I don't know how you checked solenoids if solenoid became hot. I hope you didn't connect it to the battery directly. You should check it with a tester and it should have around 23 ohm. It can became hot if you connect it to the battery, cause in that case it takes ~0.5A and 6W can heat it up. Link to comment Share on other sites More sharing options...
paulbaumgartner Posted August 9, 2005 Author Report Share Posted August 9, 2005 I checked the solenoids by entering P010 (A solenoid) and P011 (B solenoid) test codes in the PCM. It cycles the solenoids from HI to LO at about 1 cycle/ 2 seconds and allows you the disconnect connector and test voltages and what ever other troublshooting items you may want to try. This test is handy because you can do it with the engine off and solenoid componants exposed (fluid drained/pan off). Paul Link to comment Share on other sites More sharing options...
32v_dohc Posted August 9, 2005 Report Share Posted August 9, 2005 Are you sure you are not just feeling the torque convertor when it is locked and unlocked? To verify enter diagnostics (press warmer and off for three seconds) You should get any codes and then PCM? press fan up twice and it should show you PD01 and a value. Use fan speed to page through the values to PD76. On the highway is the gear ratio near .68? Then page to PD73. With the convertor lock it should be 0-5 but when it is unlocked it will be much higher. HTH John Link to comment Share on other sites More sharing options...
navion Posted August 9, 2005 Report Share Posted August 9, 2005 Paul, Just curious. But are you experiencing a TCC lock-up failure? I would thing that you should be getting some codes if so. Does the engine really rev up or does it just change a couple of hundred RPM? Your PM says that you have the engine out now. So now is the time to change the torque converter and input shaft seal and "O" ring. Britt Britt Link to comment Share on other sites More sharing options...
paulbaumgartner Posted August 9, 2005 Author Report Share Posted August 9, 2005 I think th TCC is orking properly no PCM or TCS codes of any kind. I fear the worst. I can actually throttle the TCC and change the RPM's appropriately for what I think is proper TCC operation but moderate throttle starts the slipping all the way until I am engaged in third gear. Paul Link to comment Share on other sites More sharing options...
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