PrecisionX Posted October 12, 2018 Share Posted October 12, 2018 Hi guys, kind of a freak out today. My 01 SE has 192,xxx on it and is very well maintained. On the highway at about 70mph my RPMs just kept climbing as I pressed the gas. I was accelerating as well but it seemed like the truck didn’t want to get into the next gear and it was holding at 4K and if I floored it to try and get it to change into the next gear the RPMs would climb as well as my speed. I’d take my foot off the gas and the RPMs would drop while maintaining speed. I turned around, drove home and shut it down. I started it back up and drove to my shop. The issue did NOT happen again. Any ideas? Really hoping my Tranny isn’t on its way out. If it was what would I be looking at for replacement cost? Or rebuild cost? Link to comment Share on other sites More sharing options...
colinnwn Posted October 12, 2018 Share Posted October 12, 2018 I have a manual partly because of the Torqueflite in my old Scout. So no specific advice, but I have some suspicions. I wouldn't get too excited yet. If you don't like to do your own work, take it somewhere for a diagnostic you trust, then if it's bad start talking to them about rebuild vs JY replacement.If you like to do your own work, have you read the service manual troubleshooting section for the AT? Sent from my SM-N950U using Tapatalk Link to comment Share on other sites More sharing options...
QuasarDecimari Posted October 12, 2018 Share Posted October 12, 2018 Are you running oversized tires from stock? If I remember right, the stock tire size is 29", anything above that is going to change the way your transmission shifts. When I put on my 33" tires, before installing the speedometer chip to tune my tranny shift points, it would have a really hard time anywhere above 65 as well, and I'd have to force it to shift by letting off the gas slowly until it was basically choking the engine for those RPMs, and it would finally shift hard. Link to comment Share on other sites More sharing options...
PrecisionX Posted October 12, 2018 Author Share Posted October 12, 2018 I actually do have oversized tires but not huge. 245/75/16s which is a 31.5 I believe. Link to comment Share on other sites More sharing options...
mjotrainbrain Posted October 12, 2018 Share Posted October 12, 2018 27 minutes ago, PrecisionX said: I actually do have oversized tires but not huge. 245/75/16s which is a 31.5 I believe. Due to most tire manufacturers exaggerating their tire sizes (ie. a "32" is really anywhere from 31.5-31.8 usually), you do have a decent sized tire on there IMO. When I had 32x11.50r15 on my '02 QX4 it would have a bit of a hard time finding that last gear sometimes, especially if it dropped down a gear to climb a long hill; it would take FOREVER to figure itself out on the other side. That being said, how long have you had oversize tires? If it's been a while now, this issue probably isn't coupled to that. Was the vehicle fully warmed up? I know auto trannies sometimes don't shift right if they're cold, especially if you have oversize tires too. 1 Link to comment Share on other sites More sharing options...
PrecisionX Posted October 12, 2018 Author Share Posted October 12, 2018 Fired it up and drove. 55 degrees. It’s happened before but didn’t seem to hang on this long. Oversized since I bought it 75,000 miles ago. Link to comment Share on other sites More sharing options...
QuasarDecimari Posted October 12, 2018 Share Posted October 12, 2018 8 minutes ago, PrecisionX said: Fired it up and drove. 55 degrees. It’s happened before but didn’t seem to hang on this long. Oversized since I bought it 75,000 miles ago. Bigger tires unfortunately do really add that extra stress to the transmission, especially the shift points, as the wheels are now turning at a different rate relative to your vehicle speed than originally programmed from the factory. Other than regearing, which will only help a little, the only other fix I know of is to install a speedometer adjustment chip like the one from 12OClockLabs, which can be a tricky animal of its own that also kinda messes with the transmission. Link to comment Share on other sites More sharing options...
colinnwn Posted October 12, 2018 Share Posted October 12, 2018 I would flush and fill the tranny fluid, and replace the filter if you haven't recently. Look for milky appearance that might indicate a cooler leak. If that looks good and no change, it is probably a sticking solenoid in the valve body and needs to be cleaned well and rebuilt maybe just the valve body. But if follow the SM troubleshooting first.Sent from my SM-N950U using Tapatalk 1 Link to comment Share on other sites More sharing options...
QuasarDecimari Posted October 12, 2018 Share Posted October 12, 2018 I would flush and fill the tranny fluid, and replace the filter if you haven't recently. Look for milky appearance that might indicate a cooler leak. If that looks good and no change, it is probably a sticking solenoid in the valve body and needs to be cleaned well and rebuilt maybe just the valve body. But if follow the SM troubleshooting first.Sent from my SM-N950U using TapatalkThis doesn’t hurt either. When I changed my transmission filter, I filled up the tranny with fresh fluid, ran it for a day or so, and the next day drained it all out again to refill, hoping to get as much old fluid out of the torque converter and so on as possible. It actually improved the smoothness of shifting a lot.Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
PrecisionX Posted October 12, 2018 Author Share Posted October 12, 2018 Flushes are the devil. They can actually cause a good one to go bad but new fluid isn’t a bad thing so I might go that route. Link to comment Share on other sites More sharing options...
colinnwn Posted October 12, 2018 Share Posted October 12, 2018 I don't mean using a product or having a shop do a machine flush. I just mean drain thoroughly and replace the fluid. Doing it twice might be good if particularly dirty. Sent from my SM-N950U using Tapatalk Link to comment Share on other sites More sharing options...
mjotrainbrain Posted October 12, 2018 Share Posted October 12, 2018 34 minutes ago, colinnwn said: I don't mean using a product or having a shop do a machine flush. I just mean drain thoroughly and replace the fluid. Doing it twice might be good if particularly dirty. Sent from my SM-N950U using Tapatalk Yes, specifying the method is important. No idea how the volume of fluid compares between R50's and 4th gen 4Runners, but the standard practice there is to drop the pan 3-4 times and replace the 3-4 quarts that come out when doing so. This will replace near enough to all the fluid without any real risk of harm to the tranny, other than the inconvenience of having to do it. The more things that get brought up on here, the more maintenance I realize I should have done to mine... Link to comment Share on other sites More sharing options...
onespiritbrain Posted October 13, 2018 Share Posted October 13, 2018 It sounds like your OD solenoid to me. If it happens again, hit your OD off button a bunch and see if it has any effect.If you’re comfortable, you could do a flush yourself with the trans cooling lines. If you need to know how just say so and I’ll post up a step by step. Unless you’ve gone a very very long time with no trans oil change then fresh oil isn’t going to hurt anything. It’ll stop the excessive wear in its tracks though..However, considering the solenoid may be sticking, you might be in a very badly spent trans oil situation. You need to drain some oil from your transmission pan, take some pictures, and post them up. Soak up the oil in a white paper towel and take some pics. 1 Link to comment Share on other sites More sharing options...
QuasarDecimari Posted October 14, 2018 Share Posted October 14, 2018 Like you were saying, a real flush is the devil. Which would mean a machine would pump new fluid in until all the old fluid is pushed out, but this can easily kick up clutch pack material and debris to clog more things up. If you’re going to aim to change all of the fluid, like I said, drain some, fill some, run it for a bit, drain it, fill it, repeat until it’s pretty clean. This way you’re not forcing new fluid through the tranny, and instead just letting it work the old fluid out itself. I did that around 20,000 miles ago and it’s going nice and strong. Link to comment Share on other sites More sharing options...
PrecisionX Posted October 14, 2018 Author Share Posted October 14, 2018 My guy changed the fluid twice and the filter, said it got better and then a third time even better. He said the fluid smelled a little funny and there was a lot of sediment in the pan but no metal or anything alarming. He thought the selenoid might have been gunked up. 1 Link to comment Share on other sites More sharing options...
QuasarDecimari Posted October 15, 2018 Share Posted October 15, 2018 My guy changed the fluid twice and the filter, said it got better and then a third time even better. He said the fluid smelled a little funny and there was a lot of sediment in the pan but no metal or anything alarming. He thought the selenoid might have been gunked up.Keep us updated on the results when you get to driving it again! Hopefully that’s all it was.Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
onespiritbrain Posted October 15, 2018 Share Posted October 15, 2018 There was a guy that solved his shifting issues with a $50 junk yard valve body swap. That’d definitely be worth a try, especially if you’ve got a bunch sediment and crud in your current valve body.You might also consider a real filter to go along with a new valve body. That thing that’s in the pan isn’t a filter (and actually Nissan doesn’t even call it a filter- it’s a screen). Otherwise you might end up where you are shortly down the road. https://www.amazon.com/Magnefine-Magnetic-Inline-Transmission-Steering/dp/B0787KWZPSI wish I had tried a valve body swap before buying a whole transmission.. 1 Link to comment Share on other sites More sharing options...
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