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Hello, my 2003 Xterra won't shift in to drive while hot. Shifts fine while cold. Changed transmission filter still same. Can anyone tell me what is going on? Is my transmission toast?
Transmission not shifting into drive when hot
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You changed the filter, does that mean you changed the fluid too? A complete fluid flush and fill will refresh the fluid in the torque convertor too and that can make all the difference. It's probably $100 in fluid but it's cheaper than a mechanical teardown if it gets you back to normal shift engagement.
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Just changing the fluid in the pan is not enough, especially if the original fluid has a lot of miles on it.
The torque converter has a lot of fluid inside it and only a complete flush will clean that out.
You mention it won't shift into drive when hot.
Have you tried starting off in L1 and upshift manually?
If you are able to take off in L1 and upshift from there then it could be a problem with the electronically controlled solenoids.
If the problem persists only a diagnostic by a shop will tell you the precise problem.
The torque converter has a lot of fluid inside it and only a complete flush will clean that out.
You mention it won't shift into drive when hot.
Have you tried starting off in L1 and upshift manually?
If you are able to take off in L1 and upshift from there then it could be a problem with the electronically controlled solenoids.
If the problem persists only a diagnostic by a shop will tell you the precise problem.
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OK thank you I will do a full drain. I can drive in any gear when hot. Except drive. Thank you for all the excellent info.
Good luck.
If doing a complete flush does not fix it then a visit to a shop might be the only option left.
Make sure you understand the difference between a "drain" and a "flush".
Draining the fluid from the pan gets only about half of the fluid. Most of the rest of it is in the torque convertor. If there's a small drain on the TC, then draining that and refilling will get a very large percentage of the fluid.
Flushing means that the trans cooler lines are disconnected and then either a machine is used to flush new fluid in while old fluid comes out. Another method is to start the engine and let one of the lines pump the fluid into a pan while new fluid is being poured in.
Just a heads up: GM is one of the big manufacturers that recommends against any kind of flush (machine or self-pumping) as a means of protecting themselves from any damage that they'd be forced to cover under warranty. While I can see that a machine whose pressure is turned up too high could cause a problem, letting the engine pump it shouldn't be an issue so long as it never runs too low.
The take-away is to get all or most of the fluid out, not just half of it.
Draining the fluid from the pan gets only about half of the fluid. Most of the rest of it is in the torque convertor. If there's a small drain on the TC, then draining that and refilling will get a very large percentage of the fluid.
Flushing means that the trans cooler lines are disconnected and then either a machine is used to flush new fluid in while old fluid comes out. Another method is to start the engine and let one of the lines pump the fluid into a pan while new fluid is being poured in.
Just a heads up: GM is one of the big manufacturers that recommends against any kind of flush (machine or self-pumping) as a means of protecting themselves from any damage that they'd be forced to cover under warranty. While I can see that a machine whose pressure is turned up too high could cause a problem, letting the engine pump it shouldn't be an issue so long as it never runs too low.
The take-away is to get all or most of the fluid out, not just half of it.
If the fluid wasn’t changed as often as it was supposed to be then the trans is shot and will need a rebuild. The only way you can tell is to be the one who baught it new, if it’s been neglected then when you flush it you remove the fine metal flakes that’s allowing it to grab on the drum inside the transmission, once this happens it’s just gonna keep slipping. When it’s cold fluid is thicker than once it’s at 195 degrees. This is a issue with any automatic transmission, doesn’t matter what vehicle.basically if it wasn’t done every 35k miles it should be left alone to prevent this from happening.
Sorry, but I have to call out this myth.
The transmission uses clutches and metals to shift. When the trans is new, it has absolutely clean fluid and it works perfectly. As it ages, flakes get into the fluid, which is filtered to help keep it as clean as possible. Otherwise, those flakes could collect in places and cause issues, much the same as having a heart attack.
The trans was not designed to use flakes to shift. They do not help, but instead are more like sandpaper and just make things worse.
It is never a bad idea to change the fluid. There is more to the fluid than just the oil. There are detergents, anti-corrosion agents, viscosity enhancers, etc. Those all wear out as it gets older. Changing the fluid restores their strength and helps the transmission to work better.
NOT changing the fluid is not a good idea. Ever.
Spot on right there with the transmission fluid. The chemistry of the fluid is extremely important to performance! I've done full flush transmission fluid changes that have totally fixed poor shifting issues in automatics.
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