# Pathfinder shifting problem



## Landherr (Aug 2, 2005)

I have a 1996 Pathfinder. 3.3 liter engine with automatic transmission and 4 wheel drive. The vehicle has 135,000 miles on it. It has been shifting quite rough from 1st to 2nd gear for about 3 months now. I tooik it to a reputable shop which installed a new accumulator in the transmission. This did not solve the problem. I then took it to the local Nissan dealership, who, after 2 days of "diagnosis" told me the vehicle needed a new valve body assembly installed (for the price of $1800). At this point I said STOP. The vehicle runs fine, it just shifts hard from 1st to 2nd gear. Does anyone know of something else that could be causing my vehicle problems?


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## b67 (Apr 21, 2004)

Landherr said:


> I have a 1996 Pathfinder. 3.3 liter engine with automatic transmission and 4 wheel drive. The vehicle has 135,000 miles on it. It has been shifting quite rough from 1st to 2nd gear for about 3 months now. I tooik it to a reputable shop which installed a new accumulator in the transmission. This did not solve the problem. I then took it to the local Nissan dealership, who, after 2 days of "diagnosis" told me the vehicle needed a new valve body assembly installed (for the price of $1800). At this point I said STOP. The vehicle runs fine, it just shifts hard from 1st to 2nd gear. Does anyone know of something else that could be causing my vehicle problems?


How rough is rough, my 1-2 shift is kind of rough if I give it a good amount of throttle then ease off the gas just before the shift - I'm thinking its got something to do with with the computer adapting to the driver's habbits (if NIssans even do this)


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## deepsky (Aug 10, 2005)

Mine does the same thing. Nissan dealer even told me it was my transmission and they rebuilt it, guess what! I still have the same problem. No one has been able to figure out why it is shifting hard and how at times I have to let go of the gas a bit and and gradually excellerate so it shifts smoother, otherwise my RPMs go higher than normal. It didn't do this when I first got it 2 years ago, it's very annoying.


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## b67 (Apr 21, 2004)

deepsky said:


> Mine does the same thing. Nissan dealer even told me it was my transmission and they rebuilt it, guess what! I still have the same problem. No one has been able to figure out why it is shifting hard and how at times I have to let go of the gas a bit and and gradually excellerate so it shifts smoother, otherwise my RPMs go higher than normal. It didn't do this when I first got it 2 years ago, it's very annoying.


When I switched from castrol syn ATF to Mobil syn ATF mine did subside enough to notice


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## Yagaman (Aug 13, 2005)

*Mine too*

I have a 95 4wd and it does the same thing. I have noticed that once it warms up quite a bit, it will shift more smoothly. I do the same (let off of the gas just before it reaches the shift point for second to make it less harsh). The hard shift will eventually wear out the discs or band that is activating to make second gear happen.

These vehicles did not do this when they were new. I have only had my Pathfinder for a couple of months and I am determined to find out what it takes to make this right. My guess is that it is a clogged or failing shift valve. If it takes more speed (hence more RMP in 1st gear) to make it decide to shift into second gear, and it does not activate smoothly (gradually) then I am led to believe that it is taking a much larger amount of pressure to overcome the shift valve's opperation/initiation point (for second gear) so when it does engage, it is drastic.

You can learn alot about automatic transmissions like I did on How Stuff Works .com (If you're into that kind of thing) The illustrations help allot.

If you find something (or even a possible something) before I do, let me know. [email protected]


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## mks (Aug 13, 2005)

*Warm vs cold shifting - better when warm!*



Yagaman said:


> I have noticed that once it warms up quite a bit, it will shift more smoothly. ... My guess is that it is a clogged or failing shift valve. If it takes more speed (hence more RMP in 1st gear) to make it decide to shift into second gear, and it does not activate smoothly (gradually) then I am led to believe that it is taking a much larger amount of pressure to overcome the shift valve's opperation/initiation point (for second gear) so when it does engage, it is drastic.



We are having the same experience with our 90. In fact it will completely miss a kick down shift (spins like neutral) at freeway speeds UNTIL it has been driven about 8 miles. THen it works like a new tranmission. 

I wonder if the prior owner put the wrong kind of fluid (appears new) in there?

It almost makes me hesitate to put a cooler on the tranny for fear it will cool down and mis-shift again!

-Michael


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## Landherr (Aug 2, 2005)

*Results of my tranny overhaul*



deepsky said:


> Mine does the same thing. Nissan dealer even told me it was my transmission and they rebuilt it, guess what! I still have the same problem. No one has been able to figure out why it is shifting hard and how at times I have to let go of the gas a bit and and gradually excellerate so it shifts smoother, otherwise my RPMs go higher than normal. It didn't do this when I first got it 2 years ago, it's very annoying.


My transmission was overhauled by Kennedy Transmission here in Roch. They noticed a lot of metal filings in the pan as soon as they took off the pan cover. There is a bushing in the planetary gear set which disintegrates. The filings from this clog the valve body. Flushing the valve body and doing the replacement of parts associated with an overhaul completely corrected my problem. Works better than when I bought it 3 years ago. Spendy, but worth it as I hope to keep the vehicle for another 3 years


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## mks (Aug 13, 2005)

*Mine does the same and misses shifts until warm*

Mine will shift hard too and will also kick down into (what seems like) neutral at passing speed on the freeway UNTIL running about 8 miles - then all is fine.

This makes me wonder if it is still a good idea to put a cooler on this 90 pathy with 200K miles. My concern is that it will cause the tanny to run cool(er) and cause it to exhibit the hard shifting and neutral kickdown problem. 

Ideas?

-Michael


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## Landherr (Aug 2, 2005)

*Bite the bullet*



mks said:


> Mine will shift hard too and will also kick down into (what seems like) neutral at passing speed on the freeway UNTIL running about 8 miles - then all is fine.
> 
> This makes me wonder if it is still a good idea to put a cooler on this 90 pathy with 200K miles. My concern is that it will cause the tanny to run cool(er) and cause it to exhibit the hard shifting and neutral kickdown problem.
> 
> ...


It's probably a wear out problem inside the tranny just like mine was. Take it to a reputable shop and have them check inside the pan for metal filings. It's spendy to get them rebuilt. With 200,000 miles you may be staring a vehicle trade in the face.


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## Yagaman (Aug 13, 2005)

All tranys have a magnet in the bottom of the pan to catch any metal that passes by. Even normal wear will make it seem like there is allot of metal gathered around your magnet. If you see an excessive amount of metal and/or large pieces of metal (the size of pencil lead or bigger) then you have reason to worry.

I have often been told that a power flush (or back flush) will do more harm to your trany than good because it causes irregular amounts of pressure in the control lines. I am considering getting a power flush done in attempt to clear out any clogged lines or sticking shift solenoids.

Any thoughts??


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## Landherr (Aug 2, 2005)

*Suggestion*



Yagaman said:


> All tranys have a magnet in the bottom of the pan to catch any metal that passes by. Even normal wear will make it seem like there is allot of metal gathered around your magnet. If you see an excessive amount of metal and/or large pieces of metal (the size of pencil lead or bigger) then you have reason to worry.
> 
> I have often been told that a power flush (or back flush) will do more harm to your trany than good because it causes irregular amounts of pressure in the control lines. I am considering getting a power flush done in attempt to clear out any clogged lines or sticking shift solenoids.
> 
> Any thoughts??


Make sure they power flush the valve body


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## Yagaman (Aug 13, 2005)

Landherr said:


> Make sure they power flush the valve body


Are there different types of power flushes? How do I make sure the one I get is flushing out the valve body?


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## Landherr (Aug 2, 2005)

Yagaman said:


> Are there different types of power flushes? How do I make sure the one I get is flushing out the valve body?


The valve body is one component inside the tranny case. Just make sure that component gets flushed. Flushing the whole unit sounds like a good idea.


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## architectdave (Aug 29, 2005)

Okay guys I have 220k miles on my 97 se and i have this problem more frequently as time goes on. the trans is very sensative to fluid breakdown so the solution is to change it more frequently. I change mine every 50k miles and the problem goes away. Its that simple. The guy who does it puts in a conditioner for olders transmissions as well. 

I will tell you the older it gets the more frequent the changes are.....


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## Yagaman (Aug 13, 2005)

architectdave said:


> Okay guys I have 220k miles on my 97 se and i have this problem more frequently as time goes on. the trans is very sensative to fluid breakdown so the solution is to change it more frequently. I change mine every 50k miles and the problem goes away. Its that simple. The guy who does it puts in a conditioner for olders transmissions as well.
> 
> I will tell you the older it gets the more frequent the changes are.....



The last time I changed my filter and fluid I did not notice a change. I have put in a conditioner (maybe not the right one) and only have a couple thousand miles on it since the change. It is still not shifting correctly. Any thoughts?


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## architectdave (Aug 29, 2005)

Yagaman said:


> The last time I changed my filter and fluid I did not notice a change. I have put in a conditioner (maybe not the right one) and only have a couple thousand miles on it since the change. It is still not shifting correctly. Any thoughts?



At this point my guess would be the others are correct and the valve body is wearing beyond the limits the viscosity the new fluid can make up for....

we are all doomed.....


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## Landherr (Aug 2, 2005)

architectdave said:


> At this point my guess would be the others are correct and the valve body is wearing beyond the limits the viscosity the new fluid can make up for....
> 
> we are all doomed.....


Bite the bullet guys. It's not the valve body wearing out it is samall bushings found elsewhere in the tranny whic wear out and send the filings into the valve body to plug it. Frequent fluid changes may wori for a while but eventually larger chunks let loose and plug the valve body. Replace the disintegrated bushings and power flush the valve body. (Essentially, do the tranny overhaul). It's either that, or buy a neck brace.


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