Hard Downshift During Acceleration at Highway Speeds
10-23-2017, 05:05 AM
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Hard Downshift During Acceleration at Highway Speeds
Hi All-
I recently purchased a 2002 Tundra 4wd. The transmission has a somewhat hard shift when downshifting from OD to 3rd in the highway. It’s not super hard but there is a noticeable bump felt in the vehicle. It does not occur when you manually press the OVERDRIVE OFF button or when the shift occurs at 40-50 mph. It only occurs at highway speeds and it does every time at those speeds. So far I have done two drain and drills with Toyota DOT 3 fluid. There has been no change. I am considering doing the auto rx thing next.
Any thoughts? I’ve read about the planetary gear but it sounds like that is a huge CLUNK and this has been happening for at least several thousand miles. Maybe a bad shifting solenoid or pressure switch?
thanks
Andy
I recently purchased a 2002 Tundra 4wd. The transmission has a somewhat hard shift when downshifting from OD to 3rd in the highway. It’s not super hard but there is a noticeable bump felt in the vehicle. It does not occur when you manually press the OVERDRIVE OFF button or when the shift occurs at 40-50 mph. It only occurs at highway speeds and it does every time at those speeds. So far I have done two drain and drills with Toyota DOT 3 fluid. There has been no change. I am considering doing the auto rx thing next.
Any thoughts? I’ve read about the planetary gear but it sounds like that is a huge CLUNK and this has been happening for at least several thousand miles. Maybe a bad shifting solenoid or pressure switch?
thanks
Andy
11-29-2017, 12:12 AM
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So if I read you right, you're downshifting from a higher gear to a lower and you get a jolt in the transfer? Along with a noticeable rise in rpm? That sounds like normal functioning. Its the engine slowing itself down.
And then you changed the...assuming ATF with DOT 3? Dont think that's gonna work DOT fluid is usually for clutch and brake fluid systems. Unless you got a manual trans. I hope I misunderstood. Please clarify. From what it sounds, you have an automatic. Suspect solenoids and things if you're getting trans related CEL codes.
And then you changed the...assuming ATF with DOT 3? Dont think that's gonna work DOT fluid is usually for clutch and brake fluid systems. Unless you got a manual trans. I hope I misunderstood. Please clarify. From what it sounds, you have an automatic. Suspect solenoids and things if you're getting trans related CEL codes.
Last edited by 75w90mantraN; 11-29-2017 at 12:16 AM.
11-29-2017, 01:38 PM
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Thanks for the reply!
The DOT 3 thing was just a mixup. I used Toyota ATF DEX III.
The hard shift is not normal operation. It’s a hard shift. Not enough that it feels like the transmission dropped out, but harder than it should be. I had a trasmnission shop check it out and they acknowledged the issue but said they didn’t think it was tearing into now. If it’s something relatively simple I was hoping to address it.
The DOT 3 thing was just a mixup. I used Toyota ATF DEX III.
The hard shift is not normal operation. It’s a hard shift. Not enough that it feels like the transmission dropped out, but harder than it should be. I had a trasmnission shop check it out and they acknowledged the issue but said they didn’t think it was tearing into now. If it’s something relatively simple I was hoping to address it.
11-29-2017, 10:55 PM
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Since its a recent purchase, its good to catch up on the maintenance. So a good drain and fill, along with trans filter change (if serviceable) is always money well spent. Proper level is important. As long as no check engine lights coming on and the shifting patterns dont change for the worse, just keep an eye on it.
If the trans fluid hasnt been changed at recommended intervals, I'd do a second drain and fill a few hundred miles later, especially if what came out was dark brown or had metal shavings.
If the trans fluid hasnt been changed at recommended intervals, I'd do a second drain and fill a few hundred miles later, especially if what came out was dark brown or had metal shavings.
