It sounds like a throwout bearing, BUT ...

[Chuck Tribolet]

I've got an '01 Pathfinder with a stick shift. It's recently developed a growling noise that sounds like a throwout bearing,
It happens when I push the clutch in and coast down to a stop light. What's strange is that the growling goes away when
the speed gets down to 10 MPH. I'd think a throwout bearing would keep growling even when stopped.

What else could it be?

Chuck

[Towncivilian]

I have no idea about manuals. I vaguely remember reading something like this before, maybe on NPORA somewhere, but after 10 minutes of searching I didn't find anything similar to your issue.

Have you kept up with transmission fluid & clutch fluid changes?

[chris_clark1979]

Does it still have the growling sound when you are shifting gears or if you were to hold the clutch in while sitting at a light or while driving? If so its your throw out bearing and you might as well get the clutch and disk changed out. You don't need to get a new pressure plate as long as the springs are not busted or missing just get it resurfaced and its as good as new.
If not check the oil in the transmission and if you haven't changed it change it. And if that doesn't fix it look into a new transmission in a few years. its gonna be the bearings in side the transmission..

[Chuck Tribolet]

It does not do it with the clutch in at a stop light, which is the key thing that makes me suspect it's not the throwout bearing. It doesn't do it shifting gears while driving but that's pretty quick and there's not much difference in rotation for the throwout bearing to handle.

transmission oil was changed a few months ago.

What do you mean by ""disk"?

Chuck

[chris_clark1979]

Sry. I mean't clutch disk.
So it only does the growling sound when your off the clutch?

[Chuck Tribolet]

It happens when I push the clutch in and coast down to a stop light. What's strange is that the growling goes away when
the speed gets down to 10 MPH.

[chris_clark1979]

Ok then.. Did you check all the U-joints in the drive shaft's and the wheel bearings? If you did I would get all 4wheels off the ground and drive it and have a assistant under it to see exactly were the noise is coming from. Cause it can radiate from other parts close to it.

[Chuck Tribolet]

Checking U-joints was the top item on my short list, which I haven't gotten to (two and a half weeks of vacation means lots of catch up at work). It would be really nice to have it be a U-joint -- inexpensive and just an hour or so of work.

[Chuck Tribolet]

I crawled under today. The rear driveshaft U-joints seem fine. I could make it make the noise
with the rear jacked up off the ground, but Adm. Linda couldn't, so I didn't get a chance to hear
where the noise was coming from.

[Chuck Tribolet]

I've come to the conclusion that it's clutch-related. Here's what led me to the conclusion.

1. It goes away if I put it in neutral with the clutch in.

2. It goes away if, with the clutch in, I rev the engine to the correct RPM for the speed and gear I'm in (e.g. 2500 RPM for 25 MPH in second gear (about 100RPM per MPH)

It could be the pilot bushing, it could be a dragging clutch.

[chris_clark1979]

Yea it something in the clutch for sure.. Its a fairly easy task as long as you take your time and don't rush.. And save ALOT of money..

[Chuck Tribolet]

Current status: after a week or two, the noise went away. Right now, all is well. Time will tell.

Chuck

[Towncivilian]

Nice that it disappeared. Which fluid do you use in the trans again? I forgot. Valvoline 80W-90 gear oil is not suitable for the manual trans; Valvoline's PDS specifies a different fluid for synchronized manual transmissions.

[Chuck Tribolet]

I don't remember exactly what I used, but the FSM said to use API GL-4 75W-90, which the oil I used met.
It ALSO met GL-5.

And folks, GL-5 is NOT better than GL-4. Nonsynchromesh transmissions (e.g. 18-wheeler) spec GL-5.
It's possible for an oil to meet both GL-4 and GL-5, and that's OK.

Chuck

[Towncivilian]

I believe in most cases, a lubricant meeting both GL-4 and GL-5 specifications is suitable for use in a differential which calls for either, not a manual transmission. This is backed up by Valvoline's PDS for 80W-90 High Performance gear oil - see the product data sheet.

I would suggest you try to find out what you used, Chuck. Perhaps plan an earlier change out if the lubricant used turns out to not be suitable.

[Chuck Tribolet]

The receipt will turn up when I sort the 2012 receipts prior to doing my taxes.
I'll post back then.

Chuck

[Chuck Tribolet]

I found the receipt. The manual transmission got Valvolene High Performance 75W-90 gear oil which is
API GL-4 and GL-5. The bottle says "Recommended for all hypoid differentials (conventional and limited slip) and manual tranmissions where API GL-4 or GL-5 fluid is specified." That would seem to fit what the FSM specs for my manual transmission: "API GL-4, viscosity SAE 75W-90 only".

Chuck

[Towncivilian]

I think it should be fine, then. The viscosity is proper and the bottle claims compatibility.

[barnum]

Any update on this Chuck? My Pathy is exhibiting similar behavior. Just took a trip to DC and back and now its whirring every chance it gets. It has done it a few times before when cold but would always go away a couple miles down the road.

Blasted downtown DC New years Eve traffic.

[Chuck Tribolet]

Almost a year later, it's still gone.

Chuck