Torque Converter Issues

[tecciball]

I have noticed some weird shifting when my Pathy makes its first shift from 2nd to 3rd. When it goes to shift, the engine RPM will run up, then the next gear hits. It does NOT clunk when the gear engages. This does not seem to happen after that first shift sequence. I had similar simptoms with my old Grand Cherokee, and they rebuilt my tranny when I took it in!

 

I took it to my local dealer in Feb to have it checked because my drivetrain warrantee will expire in Sept. I dropped it off the night before so that they could have the vehicle cold, but "they could not recreate the problem." I have since had my mechanic change my tranny fluid, but he did it the old fashion way (not the torque converter fluid). I think the invoice said he put in 4qts. The problem did not go away.

 

I mentioned this issue inside another post a while back, and someone mentioned that it might be a problem with my torque converter. Although, I might be confusing myself, since I have read many posts on many issues.

 

Thanks in advance for everyone's help.

Edited May 16, 2006 by tecciball

[OR99.5Speed]

I have noticed some weird shifting when my Pathy makes its first shift from 2nd to 3rd. When it goes to shift, the engine RPM will run up, then the next gear hits. It does NOT clunk when the gear engages. This does not seem to happen after that first shift sequence. I had similar simptoms with my old Grand Cherokee, and they rebuilt my tranny when I took it in!

 

I took it to my local dealer in Feb to have it checked because my drivetrain warrantee will expire in Sept. I dropped it off the night before so that they could have the vehicle cold, but "they could not recreate the problem." I have since had my mechanic change my tranny fluid, but he did it the old fashion way (not the torque converter fluid). I think the invoice said he put in 4qts. The problem did not go away.

 

I mentioned this issue inside another post a while back, and someone mentioned that it might be a problem with my torque converter. Although, I might be confusing myself, since I have read many posts on many issues.

 

Thanks in advance for everyone's help.

Funny, my ZJ Grand Cherokee did that too, but on the 1st to 2nd shift in the mornings, i.e. cold. That is the beginning of a failing auto tranny.

 

You did the right thing by having the fluid changed, but it will crap out. Make sure that it is noted by mechanics that the tranny is on it's way out, and check your warranty clauses, because aftermarket warranty companies are up there on the slime charts...they will do anything to not pay a claim.

[tecciball]

my 96 grand cherokee slipped going into second and third. i loved that truck, but it had so many damn problems. i sold it for my pathy!

 

i know this sounds crazy, but is there a way to quicken the onset of my tranny's demise? i have only a few more months on my original powertrain and i want the issue diagnosed and fixed before it is out of my pocket!

Edited May 16, 2006 by tecciball

[OR99.5Speed]

my 96 grand cherokee slipped going into second and third. i loved that truck, but it had so many damn problems. i sold it for my pathy!

 

i know this sounds crazy, but is there a way to quicken the onset of my tranny's demise? i have only a few more months on my original powertrain and i want the issue diagnosed and fixed before it is out of my pocket!

Mine was a 1996 too, Forest Green Laredo over Tan cloth, I actually miss the thing!

 

As far as quickening it's demise, I would say a few neutral drops would do! Normally I would frown on this behavior but in this case maybe not! Or you could put some wrong fluid in the tranny but the shop may be able to detect that. Or just stomp on it when it's hesitating to shift.

 

Makes me sick about destroying something but not a bad call for the situation.

[tecciball]

when you say neutral drops, i assume you mean foot on the gas to 3-4k rmp in N, then shift to D? sick just thinking about it...

 

any other suggestions out there? does it sound like issues with the tranny, torque converter, or possibly both?

[Slick]

have you had yer tranny fluid changed ...... ever? do you have enough tranny fluid in there???? do you have an aftermarket tranny cooler? cuz if you don't... even if you fry this tranny.. i HIGHLY suggest you get one else guess what...... you'll be there again.

 

has anyone checked yer torque converter??? :contract:

[tecciball]

i had my tranny fluid changed by a trusted mechanic about 2 months ago. i can check the fluid level, but since it was recently service, and i have not noticed a leak, i have no reason to think it is low.

 

there is definitely no aftermarket tranny cooler on my pathy. it was a lease in a prior life. i always though those were associated with towing, needed to mitigate the additional heat/strain put on the tranny when pulling a trailer...

[Slick]

i had my tranny fluid changed by a trusted mechanic about 2 months ago. i can check the fluid level, but since it was recently service, and i have not noticed a leak, i have no reason to think it is low.

 

there is definitely no aftermarket tranny cooler on my pathy. it was a lease in a prior life. i always though those were associated with towing, needed to mitigate the additional heat/strain put on the tranny when pulling a trailer...

usually yes, but auto pathys factory tranny coolers tend not to be so swift, and the tranny can stillf ry itself. bypass the stock cooler and slap an aftermarket cooler on there.... it will help a LOT in the life of your tranny.

[OR99.5Speed]

Basically, even though you changed the tranny fluid now, it's still on its last legs, i.e. too little too late. Nothing you can do really to prolong the life of it, maybe try one of those Lucas products but I personally think they are snake oil.

 

About the neutral drops, you got it!

 

Edit: About the neutral drops, don't take my advice. It's just asking to kill a driveshaft and a diff and whatever else along the way. Don't do it and I don't want to be responsible if you do!

Edited May 16, 2006 by OR99.5Speed

[4x4le]

is there a way to quicken the onset of my tranny's demise? i have only a few more months on my original powertrain and i want the issue diagnosed and fixed before it is out of my pocket!

Yea here is a better idea. Drain out some fluid so you are low. Get a fitting to connect the two hoses and bypass the tranny cooler all together. Dont allow it to got into OverD and keep it in 2nd as much as you can but dont over rev the motor too much. I had a auto cross 240sx automatic. I blew 2nd gear and only used first! I kept it in first all day because it was such a slow track and noticed no slipping. When i got on the highway i had no 2nd and a very slippy od.

 

EDIT:

make sure you set it back up all factory befor you bring it to the dealer. They defenatly would not honer the warrenty if they knew you did this!

For the small fee of $500, I wont tell them lol!

Edited May 16, 2006 by 4x4le

[tecciball]

I changed the fluid to eliminate that as a cause. I have also heard that dirty tranny fluid can effectively "hold a busted tranny together," so changing the fluid can make the slipping worse. I was hoping the problem would go away or get worse. Neither has happend.

 

And I didnt intend on doing the tranny drops. Too cruel to my beloved Pathy!

 

I think I might take my camcorder with me for a ride to document the issue. It only happens when the engine first shifts from 2nd to 3rd at moderate throttle. If you use only light throttle, it is not very noticable. The dealer likely did not notice it simply because of their location. They are in a congested area, and cannot likely run it up to the required RPM and speed soon after start to recreate the issue. I might take it to another dealer in a location where they can get a good test. It is tough though cause I need to leave it overnight, and they need to test it first thing! Who knows when they get to it!!!

 

And I dont think I want to go to the trouble of bypassing my tranny cooler, but thanks for the suggestion.

[turbopath]

Just wondering...has anyone tried replacing the valve body to see if it fixes the problem?

[4x4le]

Mine does something like that in all gears anyways and i have heard that nissan tested their cvt transmission tech on our pathy trannies. Say im taking off in first but have it in drive. It seems the motor will rev different not the same to in ratio to speed if i have it pulled down into first. The same as if it were in second and in drive as opposed to having the shifter in second and being in second. The same with being in 3rd and having od selected as opposed to having the button not selected. And sometimes is seems to use each gears different ratios when just having it in d. Like each gear shifts 3 times.

I really cant explain what im trying to say but in my case it really does not seem like a problem. It is not however caristic to a slipping tranny, and i have had plenty experience with them!!!

None of the gears seem to rev out of hand or inconsistantly. It is like each gear has 2 distinct close ratios. They are most apparent when on the freeway gong up the mountain. My buddies folks used to have a 02 3.5 2wd auto pathy brand new at the time that did the same thing and that is when they took it to the dealer as a possible glitch and the dealer said that they had a form of the cvt tranny and that it is ok.

Has anyone had anything like this happen. I think it is ok i'm just wondering if maby it is the origional poster of this thread is mis diagnosing his problem and that could be why the dealer finds no problem.

[4x4le]

Oh i forgot to comment that the valve body thing is what made me think of this. I was wondering if having the shifter in different gears has something to do with opening or closing valves that pump fluid mabye freeing up resistince in the tranny or something letting less strain be on the motor to allow it to rev different.

Or if the same thing with valves to open or close while in drive to allow for the same things to happen.

I know im speaking a foreign language but im tired and cannot find the righ words.

Lets put it this way. It happens when the same gear is being used for 20 or more seconds under accelleration some times and seems to have a benefit on accelelorating and defenatially does not seem to be a slipping tranny because each gear or supposed sub gear is solid with the throttle.

 

Yall scratching your heads at me yet? Or does someone else have the same thing happening? According to nissan you should all have experienced this wheather you noticed or not, or just cant understand what im saying. I probably would not be able to understand myself if i didnt know what im TRYING to explain.

[tecciball]

No offense 4x4LE, but I have no idea what you are talking about. My best guess is that your are comparing allowing the tranny to shift "automatically" using the D position on the shifter vs using the manual 1 and 2 positions on the shifter. Maybe repost when you are not tired.

 

Turbopath, I have not replaced the valve body. How would that relate to this potential problem with my tranny? A brief explanation would be nice. Keep in mind that I am not much of a mechanic.

 

I recorded the bad shift on my way to work this morning to show the Nissan service people. I have a video capture device, so I could post the video clip. Can this site host such a thing? I will digitize it and post it if the size isnt too big. Can someone PM me with the limits for that? Thanks.

[turbopath]

Well, what happens with a lot of other cars is the valve body builds up tarnish over time. Usually the gears you don't use as much are the first to go. ie..Reverse. It will start to take a while to go into D from Park, shifts become rough, and it will slip under load because the clutch for the gear you're in doesn't get enough oil.

[nissandoms47]

i get what your saying 4x4le. if i keep it in 1st it will revv higher then when its in drive flooring it. but mines a 96.

[XPLORx4]

I've been watching this discussion to see what comes up, but I think the observations made are not normal. What is normal is this:

 

Shifter in "D". OD on. Start from stop, accelerate normally to 65mph and then cruise on a level surface.

 

Here's what the tranny should do:

Starts in 1st gear, TC unlocked.

Shifts to 2nd gear, TC unlocked.

Shifts to 3rd gear, TC unlocked.

Shifts to 4th gear, TC unlocked.

TC locks.

 

Now, if try to lightly accelerate to 75mph, the TC may unlock, then depending on the engine load, will relock again when you are cruising.

 

If you reduce speed to 65, then disable OD, then the tranny will downshift to 3rd gear, and lock the TC. If you reenable OD, the TC will first unlock in 3rd gear, then shift to 4th, then lock again.

 

Now, if you slow to 52mph and shift to "2", then the tranny will shift to 2nd gear and lock the TC. Below 50, the TC will unlock again.

 

The unlocked TC makes it feel like the tranny is slipping, which of course, it is. That's why you don't want to drive too long with the TC unlocked. It could overheat the ATF.

 

Whenever the TC unlocks, the RPMs usually increase by about 400-600, then drop back down when the TC locks up again.

[Dirk Digler]

Isn't there a TSB on this for a shift flare problem or something?

 

Joe.

[XPLORx4]

Isn't there a TSB on this for a shift flare problem or something?

 

Joe.

Good call! Yes, there is. I read about it on the edmunds.com forums.

 

From nissanhelp.com:

 

Service Bulletin Num : 00084

Date of Bulletin: OCT 16, 2000

View Document

 

Component: POWER TRAIN: AUTOMATIC TRANSMISSION: CONTROL MODULE (TCM, PCM)

Summary: CUSTOMER MAY COMMENT THAT THE AUTOMATIC TRANSMISSION FLARES ON THE 1-2 SHIFT WHEN ACCELERATING HARD FROM A STOP AND THEN BACKING OFF ON THE THROTTLE.

 

From edmunds.com's Pathfinder forums:

 

Service Bulletin Number: NTB00084

Bulletin Sequence Number: 187

Date of Bulletin: 0010

NHTSA Item Number: SB618803

Make: NISSAN

Model: PATHFINDER

Year: 2001

Component: POWER TRAIN:TRANSMISSION:AUTOMATIC:CONTROL MODULE (TCM, PCM)

Summary: CUSTOMER MAY COMMENT THAT THE AUTOMATIC TRANSMISSION FLARES ON THE 1-2 SHIFT WHEN ACCELERATING HARD FROM A STOP AND THEN

BACKING OFF ON THE THROTTLE. *TT

 

Another post:

Transmission: I also noticed my auto-tranny pausing or flaring while shifting between 1st-to-2nd gear. There is a Service Bulletin on this complaint also. They checked it out and said they needed to order a part:

 

Part # 31036-4W001

[nissandoms47]

so the transmission control unit needs to be replaced? did they program it different on the (new) replacement one? or why does it need to be replaced. i seem to have that flare too.

[tecciball]

I stopped by the dealer on my way home from work. They didnt care about my vid. The service guy said that his tech MUST be in the vehicle when the issue occurs! He suggested leaving my Pathy for a few days so that a tech can drive it around a bit. I think I will see if they can take it over a weekend.

 

Thanks for everyone's attention. I will let everyone know what happens.

[tecciball]

So I had the Pathy at the dealer again, this time for an entire weekend so that a tech could take it home and do a test in an area other than the dealership. The idiot tech and idiot manager did not bother to listen/read the problem description I offered. The tech drove my Pathy for 85 f-ing miles and 'couldnt recreate the problem.' No $hit you couldnt recreate it, the problem only presents itself in the first 100 yds!

 

So needless to say, I am done with that dealer. There is another MUCH LESS convenient option that I will go to next.

 

I think I am gonnna monitor it for a few weeks and see how the change in morning temp effects the issue. My wife - a school teacher - will also be done soon for the summer, so it will be much easier being down to only one car.

 

The tech did tell me that when the fluid is cold, it will shift differently. Does anyone agree with that. He also said that slipping would typically be worse when the fluid is warm (thinner).

 

The problem has not been as noticable the last few days when it was much warmer during my morning commute. Also, is it noteworthly that the slipping I have noticed has happened when accelerating up hill?

[XPLORx4]

You do realize that the torque converter unlocks under certain conditions, right? When the torque converter is unlocked, it will seem like each gear is "slipping", especially when accelerating uphill in overdrive. Usually, when the torque converter is unlocked, the RPM difference in a given gear will be 400-600rpm.

 

Also, the TC does not lock until the ATF reaches operating temperature. Obviously in colder weather, it will take longer to reach operating temperature. On my truck, this can be as many as 5 miles at freeway speeds.

 

Are you sure you're noticing something totally different than normal TC locking/unlocking?

 

For example, accelerate and hold speed at 60mph. Turn off Overdrive. Note RPM. It will probably be somewhere around 3000. (The exact RPM's may be inaccurate. This is only an example, but your results should be somewhat similar.) Accelerate moderately (about 1/2-throttle) up to 70 and hold, and at the same time you start accelerating, turn on Overdrive (the light on the dash should go out). You should immediately notice that the RPM jumps up to about 3400, then a moment later, down to about 2800, and then down again to about 2500.

 

Here's the tranny state at each RPM in the above example:

3000rpm @ 60mph, overdrive Off: 3rd gear, torque converter locked

3400rpm @ >60mph, overdrive On: 3rd gear, torque converter UNlocked

2800rpm @ >60mph, overdrive On: 4th gear, torque converter UNlocked

2500rpm @ 70mph, overdrive On: 4th gear, torque converter locked

 

If this isn't what your transmission is doing, you'll have to give more details if you want better advice. Any chance you can post that video online anywhere?

[nissandoms47]

i also had another question. when im crusing at about 40 mph in whatever gear and just step off the gas completly the pathy seems to jerk a little bit. but when i gently let off the gas it seems normal what could cause this?