Transmission slipping?

[MCNPathfinder]

Hey everyone, I have an 01 Pathfinder LE with 4x4. I think my transmission is starting to slip. I've asked the dealership to look at it numerous times and each time, they've said it was fine. Today it was really bad, once it get's warmed up it seems to be okay and not really noticeable, but today it was just flaring like crazy. It was almost like when driving a stick when you have the gas down and are only engaging the clutch about halfway (ie burning it). I know there was a service bulletin released about a flare between 2-3 shifts. Maybe I could take a video and post it. I know there are some safety features put in place to protect it until it reaches operating temps, like not shifting into overdrive and stuff, but this just seems weird and self-destructive. What do you all think? If it's a problem, I'd like to get it taken care of before my warranty is up in a few thousand miles, but I'd also like to save the transmission diagnostic charge my dealership is going to charge me if they don't find anything. Thanks for the help!

[Towncivilian]

What's the trans fluid look like? Has it been serviced at a reasonable interval?

[miamiheat3332]

When its colder out, and i start the car and start driving, the trans has built in saftey features and other stuff, where like 1-2 i might be going up to 2 1/2 - 2 3/4k RPM, the time between it going from first to 2nd it will flare to like 3.2-3.5k. This is normal

[MCNPathfinder]

Thanks for the advice. Not going to lie, I've had the car since June of 2010 when I bought it at 106,000 something miles. It now has 124,000 something miles. I haven't checked the transmission fluid, let alone changed it. I spent a majority of the summer pulling a 4200 pound boat to and from the lake. What is the interval to change the transmission fluid? I'm probably going to have a pro do that and have the diff fluid and transfer case fluid changed too.

[Towncivilian]

Oh yeah, since you've been towing and don't know the maintenance history get the fluid exchanged, and the other items you mentioned are a good idea as well. There's no change interval specified in the FSM, just inspect every 15k. I'd just go with a full fluid exchange every 30k, or drain & fills every 15k.

It'd be cheaper to DIY, obviously. You should do a pan drop to get all the gunk out of the pan, then do a cooler line exchange and install an in-line filter. If you're going to be towing a lot every year, the largest auxiliary trans cooler you can afford and fit is a good idea too. There is a how-to on a pan drop here (but the fluid required is somewhat inaccurate - a pan drop takes about 4 quarts), and a cooler return line fluid exchange is also very simple to do - let me know if you'd like instructions. An in-line transmission filter installs on the cooler return line and is about $22.50 shipped. Or, if you'd rather not DIY, I'd still suggest getting a pan drop and filter change in addition to a full fluid exchange.

[yeldogt]

I would hope the dealer checked the fluid - I'm sure they did.

You should change the fluid and pay to have it inspected. The rear differential will also need to be changed -- if it is LSD it needs to be done every 15k when pulling something.

[MCNPathfinder]

Thanks again for the advice. If you've got the instructions for the cooler return line thing, that would be great. I need this truck to last me as long as possible. With gas being the way it is, it gets okay mileage for what it can tow (I get about 9-11 towing this boat, which is pretty much what my friend's Expedition gets no matter what he's doing... LOL!). I think it is an LSD rear end too, I think it's got a sticker on it that says so. Do you think the transmission shop would do all the extras you were talking about, Town Civilian? I would have no problem doing this myself, I'm a little nervous, but at the same time, I like knowing what's going on with my truck. It's just that I live with my parents, and they don't want the "mess" in their garage. Thanks for the advice.

[yeldogt]

Transmissions don't heal themselves ... if you have a problem and you want to keep the Pathfinder -- you should have this looked into. Transmission can be fixed ......they don't need to be totally rebuilt or remanufactured ..... but you risk further damage. The "flare" issue has solutions .... if it is indeed starting to slip .... it is going to fail ---- most likely while towing something far from help. And the flare is not good for the transmission friction material.


I have not heard of any transmission overheating issues while towing -- I would look into what people are using on the truck before you add any additional equipment. The transmission is very easy to do a simple fluid change -- you will get 4 quarts out and you can give the fluid a look -- same for the differentials .. very easy to do .......... Do you have the electric transfer case? this is also easy to do.

I used 5 bottles of Mobil 1 differential oil -- approved for the LSD -- so you can do both F & R with the same oil -- transmission uses Nissan D matic -- same fluid goes in the electric transfer case -- you need 6 quarts to do both. But you need to find out what is going on first otherwise you may be doing it twice.


I get all my fluids done at one time including a simple coolant change -- my local guy charges me about an hour labor -- I get all the correct fluids for him.

[Towncivilian]

You will need 12 to 15 quarts of ATF to do a thorough flush. I use Castrol Import Multi-Vehicle (I was previously using Valvoline Maxlife and I wasn't satisfied with the way the transmission was shifting). Order online and use coupon codes for some big discounts.

1. Disconnect the transmission cooler return line and secure it in a collection bucket such as a clear gallon jug. This will be the hose on the passenger side of the vehicle, leading towards the transmission.
2. Have a helper start the car while you watch the bucket - once it's half full (2 quarts), yell for the helper to stop the engine.
3. Add 2 quarts of ATF through the transmission dipstick.
4. Drain collection jug into larger jug (i.e. a Disposoil - these only hold 10 quarts though in my experience, so have something else to hold the last 5 quarts).
5. Repeat steps 2-4 until you're out of ATF.
6. Check fluid for proper level (see MA-23 for details), and recycle old ATF. Any place that takes used oil will recycle ATF.

As for the differentials, I also recommend Mobil 1 75W-90 gear oil. The combined capacity of the differentials is 4.91 quarts, but you may want to get an additional quart in case you lose a significant amount due to spillage, etc. See MA-26 for directions and torque specs of the plugs. I'd order from Advance Auto for these as well (maybe a separate order to get a larger discount).

I'd grease both driveshafts while you're down there, too. The 2001 MY R50s want NGLI #2 lithium soap base grease with molybdenum. Valvoline DuraBlend will suffice.

I don't have a transfer case, so I don't have any first-hand experience with it. You can find instructions in the maintenance section of the service manual, though.

[yeldogt]

I understand the idea behind the total flush -- but the risks IMO are not worth the benefits. A properly serviced transmission should only need a partial refresh.


And why would you not use the factory fluid ?... I purchased a case online for $65.00 and did both of mine. The factory fluid has the modifiers as intended ... I use the factory fluid in all my cars- it is easy - cheap and proven.

[Towncivilian]

If you can get factory fluid for cheap, by all means do so. Courtesy Parts sells Matic-D for $6.73/qt.

What risks are there with the method I typed? There is always some fluid in the transmission, very little chance of running anything dry.

[Empty V]

This can be caused by a dirty or faulty MAF and old fuel filter.