# Signs that a transmission is failing



## GJCF (Aug 6, 2005)

Can anyone outline a couple telltale signs that the transmission is going? I have a 97 SE with 128k. I have heard these trucks can go a long time, but I'm getting nervous that the transmission may be starting to go. Thought appreciated.


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## metro273 (Sep 16, 2005)

The major symptom is a trans that "slips". It takes a while till it shifts to a higher gear. Also you'll have dark-colored and even burnt trans fluid.
One more thing, a faulty TPS(throttle position sensor) can make the trans seem like there is a problem or even in rare instances, the TCM(trans control module) could be "bad" also. "SEARCH" around and I'm pretty sure others have had this issue also...


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## 2001pathy_SE (Apr 9, 2006)

GJCF said:


> Can anyone outline a couple telltale signs that the transmission is going? I have a 97 SE with 128k. I have heard these trucks can go a long time, but I'm getting nervous that the transmission may be starting to go. Thought appreciated.


what has your transmission done for you to think that there might be a problem with it ?


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## GJCF (Aug 6, 2005)

The first sign was shudder, like it couldn't find a gear. It has stopped doing that but it does feel like it's not staying in gear and switching quickly to a higher one (at speeds 50 or less) and finally, sometimes it takes a while to switch to a higher gear. I never let the RPMs go over 3000, just ease up on the gas and it shifts. Those are the signs.

I have been told that this could go on indefinitely; that it's not necessarily going to fail in any set amount of time, but I am concerned that something catastrophic could happen and be dangerous. So my question then becomes is this dangerous to drive?


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## Xeno (Oct 5, 2005)

A 'normal' failure is a slow process. Auto tranny usually fail in a normal fasion. As for dangerous, that depends on how you drive. If you drive dangerously, then it will be more dangerous if your tranny fails.

Go have the fluid/filer changed/flushed and have the bands adjusted & I belive you will be OK.


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## GJCF (Aug 6, 2005)

Thank you! The Nissan technicians said flushing the system could make it break down more quickly. True?


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## Xeno (Oct 5, 2005)

Yes, if they use a "solvent" or a "cleaner", because that "gunk" actually helps seal things up. That goes for those "engine cleaners" also.


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## GJCF (Aug 6, 2005)

Xeno said:


> Yes, if they use a "solvent" or a "cleaner", because that "gunk" actually helps seal things up. That goes for those "engine cleaners" also.


But you would advise flushing it? Or doing so without using a solvent (if this is possible)?


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## stillwater (Jul 6, 2006)

Your old (existing) transmission fluid is carrying bits of metal filings that have come off your transmission over the last 128K. These gritty bits are providing a modicum of extra grip for the parts to mesh on one another, kinda like sandpaper. Without them (with fresh clean, grit-free fluid) your tranny components will have less purchase on each other and will make it harder for the shifts to occur. The new fluid will reduce 'wear' of the transmission by providing better lubrication, but will make shifts harder. 

The Nissan techs are right, it's best 9 times out of 10 to keep the old fluid in use. And yes, you could go on this way for a loooong time before your tranny fails to shift or get into a gear.


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## GJCF (Aug 6, 2005)

Thanks so much for your help!


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## lewisnc100 (Apr 25, 2003)

What's your service history on the transmission so far? If you've never touched the ATF fluid in 128k miles I could possibly see leaving it alone, but if you've kept up fluid changes somewhat I definitely would go far a drain and fill to get new fluid in there.


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## stillwater (Jul 6, 2006)

Ah, good point lewisnc100. See?... it always pays to get the big picture. One of the reasons why I should include something like "...no formal training..." in my signature.


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