Jeremy M. Posted August 12, 2023 Share Posted August 12, 2023 Hi all, back for another misadventure. My brother was borrowing my car, and after a several hour long drive (GA to NC and back), my brother stopped for food and called me saying the car was not going into reverse. Once he was home, I found that in addition to reverse not working, selecting neutral acts as if the car was put in "drive". No transmission codes are present in the vehicle, and with a scan tool, selecting all different gears (Park, Reverse, Neutral, Drive, 4, 3, 2 and Low) the proper gear is displayed by the scan tool. As of the moment, I'm going through the service manual trying to find any information to explain this. Attached are pages out of the manual regarding the transmission. As far as I'm reading, it seems most likely that either a one-way clutch system has failed or a clutch pack has gone out. Also a chance that a solenoid is stuck, but not shorted or in an open circuit, so it avoids throwing a code. If anyone who is more familiar with these automatic transmissions could chip in, I'd like to have a rough idea of what I'm going into so that when I tear apart my transmission it's more "surgical" rather than a shotgun approach of a complete rebuild, which would exceed my budget, especially if I include all new shift solenoids ($300-500 each from Toyota) at-2.pdf at-22.pdf Quote Link to comment Share on other sites More sharing options...
Jeremy M. Posted August 21, 2023 Author Share Posted August 21, 2023 Just coming back with an update, as it looks like this is going to turn into a how-to post. I have found other posts on separate forums suggesting the shift solenoids could be the root cause, which was honestly my hope. With that in mind, I drained out the fluid (surprisingly dark, the fluid has been changed regularly and was last drained/filled about two years/20k miles ago). Removing the transmission pan was a tight squeeze against the exhaust mount on the bottom of the bell housing, so that was removed as well. Once that was off, the filter was removed for inspection, and no debris was inside the filter or on the magnets inside the pan. The magnets did have extremely fine metal stuck to them, but no abnormal chunks or aluminum shavings in the pan. Shift solenoids 1-4 and SLT, SLU, and SLN were removed, inspected for flattened o-rings and leaks, and bench tested with jumper leads and a 12V battery. No issues with the solenoids, all of them were activating and none were leaking. With the condition the fluid was in, I expect at least one of the clutch packs will have failed and started welding itself together, cooking the fluid in the process. It's going to be a several week ordeal, but over the next few weekends, I will remove and tear down my transmission, documenting with photos where possible, at the very least leaving an update on what the mode of failure was, as I have had issues finding anyone else's post closed out with a concrete answer. Quote Link to comment Share on other sites More sharing options...
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