Clutch problem

[Jimmy9190]

This is about my 2001 Dodge Dakota, 185,500 miles on it now and it still has the original clutch, reservoir, master and slave cylinders. It also still has the original NV3500 5 speed manual transmission. I drained and refilled the transmission with Pennzoil Synchromesh about 10,000 miles ago.

I never had any clutch type problems until today. I left work this afternoon, turned onto the main highway and soon as I got to about 30 mph I felt a "jerk" in the truck kind of like when you push in the clutch and let it back out real fast. Nothing changed with engine sound or RPM's, just had that hard jerk and the truck kept moving. It happened again about 5 or 6 times on the 20 mile ride home. I had no trouble at all accelerating to 50-60 mph, shifts were fine, no trouble going in or out of gear and I had no problems at all climbing a couple of long hills at 55-60 mph with the AC on. The clutch pedal does feel a bit more easy to move than it used to but I never really noticed it much until now.

I made it home OK and found the clutch fluid reservoir was low, it was only about half way full. I topped it off with clean DOT 3 and got my wife to operate the clutch pedal while I looked at the fluid level in the reservoir. The fluid did not move at all while she worked the pedal. Then I got under the truck and saw that there was a small amount of fluid leaking from the bottom of the slave cylinder and I had a light-colored brake fluid stain on my driveway right below the slave cylinder. I chocked the front wheels, started the engine, put it in fifth gear and let out the clutch slowly without pressing the accelerator pedal. The engine stalled and shut down. My very basic understanding of the clutch system tells me if that test made the engine stall and shut down then the clutch itself is OK and I need to replace the reservoir, master, slave and hose. I read up on it in my FSM and it does not look to be very difficult, especially with new sealed parts.

Am I on the right track here with replacing the hydraulics or do you guys think I am looking at a whole new clutch? I do not tow anything, I never go off road and I drive the truck easy, I do not hot rod it at all. I rarely ever get over 70 mph and that is only on the interstate. I usually only drive about 50 to 55 mph on local roads in my 40 mile round trip commute to work and back home again. My truck will stay parked until I get this problem fixed.

Thanks for any info on this.

 

[69GTX]

185K miles on a single clutch system puts you in the top 5% (or 1%) of all drivers. Nice job! Getting that kind of mileage on generally cheap OEM components is outstanding.

I assume that you changed the clutch fluid multiple times over the life of that transmission? That's pretty important for clutch hydraulic system longevity as clutch dust finds its way into the fluid over time. Some transmissions are notorious for that.

If you have to lower the transmission to get at the clutch, it probably makes sense to replace the clutch friction parts, release bearing, etc. as well as the hydraulics. I know on my T56 I have to lower the trans just to access the clutch/slave. If you're able to change the hydraulics easy enough I would do that first.

My neighbor rarely drove his 5 speed Frontier over 55 mph and usually only around town. Speed has little to do with clutch wear. But how one engages and disengages it has everything to do with longevity. My neighbor apparently rode his clutch hard and went through 3 of them in 30,000 miles! He sold that 2003 last year with 38K miles....and 3 clutches later. For him, 10K per clutch was "fine."

 

[expat]

I don't understand why you think the jerk is related to the clutch.

Are you sure it was not the engine ignition momentarily cutting out?
Were you operating the clutch when it jerked?

Slippage of a clutch plate normally manifests itself not as a jerk, but rather mushy engagement in the higher gears (slippage)

 

[Jimmy9190]

I am sorry to say I have never changed the clutch fluid. I have had a few brake fluid flushes done but never even took the cap off the clutch reservoir until today. Prior ignorance is my only excuse.

I did not have any problems at all with the way the truck ran today, it was fine at speed and when idling, same as always so I do not think the problem is ignition related. I really had no idea what it was until I saw the fluid leak and stain on my driveway. The stain just appeared today.

The first time the jerk condition happened was when I had shifted from first to second after making a right turn from a dead stop onto the main highway. I was at about 25 or 30 mph and accelerating but not quite ready to shift to third yet so I was not using the clutch then or at any of the other times the jerk problem happened.

 

[69GTX]

Originally Posted By: Jimmy9190
I am sorry to say I have never changed the clutch fluid. I have had a few brake fluid flushes done but never even took the cap off the clutch reservoir until today.


That's what I would do first as it will cost you at most $5-$12. Get the correct clutch fluid (usually Dot 3 or Dot 4 brake fluid) and perform some flushes to clean the fluid up via a syringe. I suspect it's dark rather than honey bronze. A dirty fluid will lead to poor hydraulic operation over time, and eventually failure. The previous owner of my car never touched it and it only had 12K miles on it (12 years old) when I got the car. It took me about 30 min and 2 flushes to clean it up from a dark gray. Now I flush it annually a couple of times (5 min after returning from a drive) and it stays perfectly clear.

Here's the simple "ranger" method. I did this on my neighbor's Frontier before he sold it. He too had never touched it. And with him having gone through 3 clutches, there was lots of friction material in that fluid. It's only brake fluid after all so you have 12 years and 185K miles on your clutch "brake" fluid. You may have a bleeder on the system that's easily accessible to push out old fluid and replace with new via the reservoir. It's possible that a seal has been compromised after so many years of being exposed to dirty fluid.

Ranger clutch care

 

[Gasbuggy]

Does not sound like a clutch issue.

 

[mk378]

You'll need to fix that leak eventually. Until you do, carry fluid with you and check the level frequently.

But the "jerking" sounds like the engine is misfiring or cutting out. Clutches don't really do that. When a clutch is worn out, heavy throttle will make the engine speed up but the truck doesn't go much faster.

 

[eljefino]

When your hydraulics are failing, shifting is going to get rougher. If you idle in neutral with the clutch out at red lights, going for first is going to be more "grindy".

There are some clutch slaves out there without bleeder nipples (saturn s-series first to mind) and they really are a lifetime sealed system, even though you can top them off. While I believe in bleeding brakes, and, well, everything, I bet more than half the hydraulic clutches in service never get it until something breaks.

 

[demarpaint]

Any clutch issues can usually be seen on the tach. It sounds like the engine is cutting out. With regard to the leak, if you have an internal slave cylinder and have to drop the transmission it would be a big mistake not to do a clutch job while you're in there. Especially with 185k +miles on the clutch.

 

[The_Eric]

Agreed. While you may be encountering the beginnings of a clutch issue, you also have an engine issue of some sort too.

 

[Jimmy9190]

Thanks for the info. I think you all are right, there may be an engine problem but I have no codes and the engine runs ok so it will be hard to find out what is wrong. I do have a good scan tool and volt meter and a lot better knowledge of the engine than the transmission. I can run some tests at home but until the problem happens again or more often I may be guessing and scratching my head a lot. It may be time to think about buying another truck. I am just not sure what to do at this point.

 

[Vikas]

There may be pending code. Have you hooked up the reader/scanner yet?

 

[Jimmy9190]

Not yet. I drove my wife's car to work today. I will scan it and check the fuel pressure when I get home.

 

[George7941]

The NV3500 in my truck has an internal slave but,from what I gather from your post, you have a slave mounted to the outside of the tranny.

If the slave is leaking, just replace the slave. No need to replace the master, reservoir or the hoses. My master cylinder was leaking air in and I replaced just the master, nothing else. I assume this is not a vehicle where the entire hydraulic system comes as one unit, prebled.

The jerkiness sounds engine related. If your scan tool allows data recording, capturing data while the engine is acting up might help in tracking down the problem.

 

[expat]

Just a thought.
I had something like this jerkyness happen to me once in the winter, it turned out I had water in the Gas.

Not sure if that could happen with ethanol blended gas.

 

[Jimmy9190]

Thanks for your ideas. My scanner does read live data and I will drive the truck to work tomorrow with the scanner connected to see if it tells me anything. The hydraulics for the clutch are sold together as a sealed pre-bled assembly. I could replace only the slave but there is no way to bleed it. The reservoir is separate and mounted higher than the master cylinder. The slave is external, mounted on the lower left side of the tranmission.

I don't know about the bad gas, I drove the truck about 80 miles yesterday before the jerk problem occurred. I would think bad gas would show up right after filling up the tank and it is about half full now. The last gas I bought was BP from a very busy station but I guess it could still be possible. My intuition is usually pretty good and I have a hunch it could be either fuel pressure or the TPS. The fuel pump has about 60,000 miles on it and is an Airtex which everybody says is terrile but it was what I could afford back when I replaced it. I hope to know more later when I do some testing at home.

 

[George7941]

If the fuel pump is maintaining adequate fuel pressure, then it is doing its job well, period. If the fuel pump is the cause of the jerkiness it will show up in fuel trim numbers and O2 sensor voltages if you can record that while the engine jerks. Water in fuel will also cause abnormal O2 sensor readings.

 

[George7941]

RockAuto lists the complete master/slave/hose assembly for your truck but it also lists the slave cylinder separately. So it is possible to just replace the slave.

You can bleed the slave, even without a bleeder screw, by stroking the slave while holding it so that the fluid entry port is at the top. Any air bubbles will be driven into the reservoir where it will dissipate.

 

[Jimmy9190]

I may try that but it would be less trouble and maybe better in the long run to replace the reservoir, master and slave all at one time and be done with it. I was thinking today the only engine management sensor that has not been replaced is the camshaft position sensor. I know when that sensor fails the engine will stall out and not run, and I wonder if it is going bad and causing an intermittent interruption on the PCI bus. There are maybe 5 or 6 sensors on the bus and when one goes bad it disrupts the 5 volt signal from all of the sensors back to the PCM and the engine will not run. I am headed out to the garage now to see what I might come up with.

 

[Jimmy9190]

Fuel pressure is fine, 50 psi at idle, spec is 47 to 51. I have no stored codes and no pending codes either. TPS voltage is OK, on the low side of normal at almost 4 volts at WOT. The TPS voltage does increase very steady and smooth when I move the throttle plate so I will leave the TPS alone for now. The fuel trims look OK to me, but I am no expert. One was 7.0 and the other was 3.1 and I did not notice any erratic FT spec, but again I am no expert.

In the Dodge world the part I called the Camshaft Sensor is actually known as the Distributor Ignition Pickup. The one I have now is original and from the research I have done when they go bad they can cause a sporadic miss when the engine is under load in the 2000 to 3000 RPM range, which is exactly the best way accurately describe the jerk problem I had yesterday.

AZ, OR and AAP all sell the Distributor Ignition Pickup and their respective web sites all say it is in stock. I will pick one up tomorrow after work and replace it and drive the truck to work on Friday. I hope I am right about the pickup/cam sensor.