Automatic Transmission Nightmare

transmissions

#1

I made the mistake of trying to start my 2000 Pathfinder 4x4 after I had drained the Automatic Transmission fluid to change it. (don’t ask why) Heard a terrible metal on metal noise and immediately stopped trying to start it. Finished replacing the fluid and the filter and started the car again. Still had terrible noise, but the car started up and sounded fine. Worked for 3 weeks with 2 or 3 problem starts before finally quitting on me. Wouldn’t turn over. I’m thinking I probably ruined my transmission, but I’m in Panama, don’t speak spanish very well and wanted a professional opinion before heading into the Nissan dealership here. Oh, the reason I was replacing the fluid and filter was because on long trips there was a problem of gear changing. Jumped between gears randomly. Can you confirm a ruined transmission and a large replacement bill?


#2

Your transmission was probably already showing signs of being defective before you changed the fluid. Running it dry might have given it a final blow.

You have no choice but to go to a qualifed place for repairs or replacement. There may not be a competent independent shop in Panama, so the dealer is your only choice.


#3

Thanks. I know I need to take her in, but I’m just curious to know exactly what happened before I try to explain it in spanish.
Update: I gave it another try starting the engine this morning. There was a noise and the electrical power seemed to drain. The console lights dimmed. It started after 2 seconds and when i took it out for 15 minutes to warm her up she ran perfectly. Checked the fluids and they were fine. Turned her off and restarted her with no problem at all.
Is it typically better to repair an automatic transmission or just to have it rebuilt or purchase a rebuilt trasnmission? I’ve been told that trying to repair one just costs more money in the long run because most likely it will fail again.
Thank you,


#4

It sound as though you might have an electrical problem as well. You should have the charging system (alternator, battery, etc.) checked out as well as the starter.

The quality of transmission repairs varies greatly, and I would only trust a few shops where I live. Since I don’t know how comptent the dealer is, and having lived in a developing cuntry, I would say a Factory Rebuild, guaranteed by Nissan would be my way top go.

Good luck!


#5

Thanks Docnick.
One last question. Is running your automatic transmission dry a really really stupid thing to do or just a not so smart thing to do? Is it always catastrophic failure or just not recommended?
Thanks again,
Rob


#6

I’m having some difficulty sorting out the symptoms. You were changing the trans fluid and started the car before refilling the trans? Correct? Since then you filled the trans and have been driving the car for several weeks and the trans is working OK but you have a terrible noise when the starting motor is cranking the engine?

I can’t tell that there is any problem with the trans, but it seems like the noise is coming from the starting motor. Perhaps the Nissan dealer has someone in the service dept who speaks english. Something here doesn’t make sense to me.


#7

Your symptoms sound more like oil deprivation than a transmission problem. I am not sure why a transmission problem would lead to your engine not starting.


#8

Sorry for the confusion. You’re right with the description. When I started the engine with no tranny fluid it made a metal on metal noise and that is the same noise it’s making now every once in a while when I start it. I just assumed it was the transmission since the tranny fluid was the only thing I messed with.


#9

There could well be problems with the starter, as well as the transmission, but between the OP’s unclear description of exactly what happened and when, and our distance of a few thousand miles from the vehicle, all of us are just giving our best guesses.

I agree that, given Panama’s third-world status, a dealership is probably the best way to go. The dealership’s parts are less likely to be “dodgy”, and their mechanics–hopefully–have had some sort of factory training. If nothing else, the dealership is more likely to have someone who speaks English, as compared to Pablo’s Roadside Flea Market and Car Repair Emporium.

As to the OP’s question, “Is running your automatic transmission dry a really really stupid thing to do or just a not so smart thing to do?”, if we say that this was merely “not a smart thing”, would you do this again? Hopefully not.

Without parsing pejoratives, let’s just say that this is not something that someone should do if he wants to get the maximum service out of his transmission.


#10

I just wanted to gauge my stupidity.
Either way I will not be trying this again.
Thanks,


#11

The auto transmission has a torque converter which is in effect a hydralic pump. Starting the car without refilling with trans fluid means the “pump” did not have enough fluid in it. Most torque converters do not drain completely unless you take some special action to drain them. So, you didn’t start the car with “0” fluid in the torque converter, there was at least some residual fluid coating the moving parts. If you stopped the motor quickly and then filled the trans with fluid, likely no long term harm. If you drove the car a few miles like this then the torque converter had enough fluid to build pressure but the trans would be low on fluid and overheat and cause damage. I think it was a just a quick start; therefore if your trans is shifting now the torque converter must be working and your trans may or may not have a problem. Your actions didn’t help but likely didn’t do substantial damage.

That leaves what is this noise? When you twist the key to start the car is that when you hear the noise? When you release the key so the starting motor should stop does the noise stop then also, or does the noise continue? If so, for how long does the noise continue? An instant? A few seconds? The entire time the motor is running? When and how does the noise go away? Do you have to stop and restart the motor? Or, does it just go away by itself?

It could be the gear the engages the flywheel hanging up and that could mean a new starter is needed. It could also mean the flywheel gears are worn. Depending on your responses there are a few other totally different things it could mean.

If you are driving the car and the transmission is shifting gears then I don’t think the noise is coming from the transmission.


#12

I did not drive the car without tranny fluid. As soon as I heard the noise I turned it off.
When the car starts up the noise stops immediately or there is no noise at all.
When the car doesn’t start, the noise only continues while I am turning the key. When I turn the key back the noise stops immediately.
I do not do anything to prevent the noise before I try to start the car other than passing the gear shifter between all the different gears.
Also, I did use a hand pump to remove the tranny fluid from the dipstick. Then I took off the pan underneath and had maybe half a quart left there.

Thanks,


#13

Look into the starter as the problem. The noise is the starter gear engaging the flywheel. When the gear catches the flywheel the motor turns over and starts. When the starter gear does not engage the flywheel is just spins and makes a lot of noise. Hopefully it is just the gear on the starter which is easy to fix with a new starter. If the gears on the flywheel are worn then replacing a flywheel is a big and expensive job. On some cars the starters have shims to make sure they work properly with no noise. Your starter has bolts to hold it in place which may have worked loose. Get the starter checked out. The longer you wait the more likely the flywheel will be damaged, so check it soon.


#14

Can’t be worse than a new transmission…I hope.

Thank you all for your advice.


#15

It sounds like the bendix assy in the starter motor isn’t fully engaging the flexplate. The first thing I would check for is a fully charged battery that has good capacity. The simplest test for this is measuring the terminal voltage and performing a load test. The next thing is to insure that the alternator is recharging the battery properly. A check for corrosion of the terminals on the battery and the cables that feed power to the starter motor and the engine ground strap(s) is also in order. Finally, the starter motor assembly itself could be on the way out.