shuck Posted August 9, 2009 Report Share Posted August 9, 2009 I have a 97 Cutlass Supreme with 142k miles on it - 3.1/4T60E. I bought it with some known transmission issues. When I bought it, the tranny was in limp mode. I managed to clear that, only to find that in order to shift from 1-2 you had to goose the power, then take your foot off the gas, then get back into it. Once it shifted 1-2, the 2-3 shift was fine, but it would not go into overdrive. I replaced the 1-2 shift solenoid without taking the transmission out of the car (which was very hard on my patience and my fingers) and that fixed the 1-2 shift problem. Then I discovered a shudder following the 1-2 shift. I replaced the vacuum modulator on the front of the transmission because when I removed the old one, the plunger moved with no resistance. That fixed the shudder on the 1-2 shift. So now, I'm down to a 4T60E that won't go into overdrive. Here are the symptoms: 1) With the shift selector in OD, the car shifts up to D just fine and will lock up the torque converter, but when you take your foot off the gas, the engine will drop to idle and the car is essentially coasting. 2) With the shift selector in D(3), the car shifts to D fine and the torque converter locks up, but the transmission stays engaged and you can engine brake like you would expect to be able to in D (3) Here is what I have checked / tested so far: 1) no codes in the PCM 2) speed sensor reports proper speed (as read by Actron scan tool) 3) brake pedal switches both operate properly and are installed properly 4) changed trans fluid and filter (while changing 1-2 solenoid) 5) 18lb of vacuum to the vac modulator 6) Load% and MAF volumes seem to be ok based on scan tool 7) pulled transmission selector witch (NSS) and tried to clean it, but it's riveted shut 8) car starts only in P and N like it should, reverse lights come on with selector in R I would really like to hope it's the transmission selector switch, but I'm not terribly optimistic that's it based on the car starting in the gears it's supposed to and the reverse lights working. Does anyone know how to test the selector switch? I hate to just throw parts at it without being able to verify they are bad. Is it possible for only the OD position in the switch to go bad? Any other inputs would be great. I'm hoping it's not going to require a rebuild, but the more I troubleshoot the problem, the more I suspect it might. I have sourced a used 4T60E near me for $60 that has about 70k miles on it, but I'm not sure I have the time or tools to swap out the transmission myself. Thanks! Ryan Quote Link to comment Share on other sites More sharing options...
hotrodolds Posted August 9, 2009 Report Share Posted August 9, 2009 The 4T65E-HD in my Cutty did the same thing when the trans got hot. I would assume there is a temp switch in the trans somewhere, and I wonder if it fails, it will keep it out of OD/4th. What does the fluid look like? It wouldn't hurt to do a pan drop, and change the filter in it, and put fresh fluid in it. Won't cost too much, and if it fixes it, it was cheap. Quote Link to comment Share on other sites More sharing options...
GOT2B GM Posted August 9, 2009 Report Share Posted August 9, 2009 I had this happen with my old Z34 and 3rd gear. Ended up being a worn 3rd gear sprag, trans would just skip 3rd and go straight from 2nd to 4th. The trans does try to engage that gear, but cant so it either skips it (in my case) or stays on the lower gear in your case (no 5th gear) Quote Link to comment Share on other sites More sharing options...
hotrodolds Posted August 9, 2009 Report Share Posted August 9, 2009 Yeah...I had a '92 CS 3.1 that would do that...only it skipped 2nd gear. Glad you mentioned that. It took trans replacement in that car. Quote Link to comment Share on other sites More sharing options...
shuck Posted August 9, 2009 Author Report Share Posted August 9, 2009 Is there any electronic reason it would not go into OD, but the TCC would still work? Quote Link to comment Share on other sites More sharing options...
shuck Posted August 10, 2009 Author Report Share Posted August 10, 2009 Well, I took it to a transmission shop today and the PCM is telling the transmission to go into OD, it just isn't going. So, I am about to start taking it out of the car. Any last words of advice before I start? I'm planning on pulling the whole engine/tranny out the top with a big cherry picker. Quote Link to comment Share on other sites More sharing options...
GOT2B GM Posted August 10, 2009 Report Share Posted August 10, 2009 That or fabricate an engine support jig to hold the engine from the top while you remove the subframe and trans from the bottom. Quote Link to comment Share on other sites More sharing options...
shuck Posted August 10, 2009 Author Report Share Posted August 10, 2009 Well, I'm about half way in. I've got the halfshafts out, the power steering pump off, most of the electrical and vacuum lines disconnected, and everything on the driver's side removed (airbox, NSS switch, throttle cables, etc). Best I can tell, I have to unbolt the downpipe, remove the A/C compressor, drain the coolant and disconnect the hoses, and unbolt the engine mounts. I'm sure I'll find something I'm forgetting. Quote Link to comment Share on other sites More sharing options...
shuck Posted August 11, 2009 Author Report Share Posted August 11, 2009 And the engine/tranny are out! My first engine pull. Had to lower the car though - my garage door wasn't high enough. Thanks for all the help! Ryan Quote Link to comment Share on other sites More sharing options...
hotrodolds Posted August 11, 2009 Report Share Posted August 11, 2009 Is there any electronic reason it would not go into OD, but the TCC would still work? Yes. The torque convertor is supposed to lock up in third gear as well. Quote Link to comment Share on other sites More sharing options...
shuck Posted August 11, 2009 Author Report Share Posted August 11, 2009 The TC would lock up in 3rd. Quote Link to comment Share on other sites More sharing options...
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