Too much metal on my tranny drain plug? Should I be concerned?

[Nathans_Dad]

My first tech question to the board on my new 84 911!

I have noticed a whine coming from the transmission under load, usually between 2k-3.5k rpm. Doesn't happen when the the car is in neutral and the engine is revved to the same area. Doesn't happen when the clutch is depressed.

Receipts show a transmission rebuild at 93,000 miles. Car currently has 103,000.

I decided to do a transmission fluid change with Swepco 201.

After much grunting and a hammer for persuasion I finally got the drain plugs loose. Both were nearly stripped. I'll be replacing them with new.

The fluid that came out was a cloudy gray green. Not pretty blue like is in the Swepco bottle. Makes me wonder if the fluid was changed since the transmission was rebuilt.

On the bottom drain plug I found a pretty decent amount of metal (at least to my newbie eye) attached to the magnet. I suppose this might be just wear on the new gears and such if the fluid was never changed out.

Take a look, should I be concerned?

[EarlyPorsche]

I've regularly seen more than that on TONS of 901's that shift and drive like new for years. I'm talking the need to scrape hard in that valley on the plug. Your transmission must be relatively fresh. In fact, on some automatics I've seen more than that after 30,000 miles of use.

[Matt Monson]

That's not a whole lot of stuff. That doesn't concern me.

What does concern me is the whine. Have you got a build sheet on the rebuild? whine make me worry that you've got a bad bearing in there that wasn't replaced, or worse yet that the R/P set up is wrong.

[Nathans_Dad]

Yeah, I'll dig up the receipt, at least it lists the parts. Makes me feel better about the plug though! I'll put the Swepco in and see if the whine goes away, meanwhile I'll get the build sheet posted later today. Off to get new drain plugs!

[Nathans_Dad]

Ok so I lied. I have a receipt from a transmission shop for shift rod, fork, trans gasket, pin and labor. Basically they pulled the transmission and it was sent out for rebuild. No paperwork on the rebuild though.

[vash]

that plug is CLEAN!

i would change out the plugs that use a regular socket, and not those 17mm allen ones. can get tricky to find. i found my at partsheaven after they let me wade thru all the cases.

[Gogar]

That's normal, not a problem at all.

Chunks of stuff= problem.

[Peter Zimmermann]

That amount of debris could have been left on the drain plug by the re-builder, who forgot to clean it. I've seen this before, as long as there were no pieces I think that you're OK.

Swepco won't help the "whine," but you don't say if the noise is gear specific. If it's just 3rd, or just 4th...

If it's all gears then I agree with Matt, there might be an install problem with the R&P. Or it might be that the cover plate (over the coupler) on the tunnel below the rear seats might not have been put back, or it might be characteristic for that transmission, or...

[Nathans_Dad]

The tunnel cover is there, the whine is audible in 2nd-5th gears.

If it is the R&P how much would I be looking at to have it fixed? I'm completely new to working on 911s and don't think I'm ready to undertake an engine drop and transmission work yet!

[Nathans_Dad]

The corollary to the question is if the whine doesn't go away, what are my chances of damaging the transmission further by driving it?

[5:04]

Sorry to steer this the wrong way, but what would it be if it was just 1 gear? Mine whines a bit in 3rd

[Matt Monson]

Originally Posted by 5:04

Sorry to steer this the wrong way, but what would it be if it was just 1 gear? Mine whines a bit in 3rd

That would be a bad 3rd gear. In both street cars and track cars 3rd is generally the most used gear and the first to wear out. The exception would be a car that spent it's life as a highway commuter, in which case 5th gear wears out. Could be the gear, could be the needle bearings under the gear.

Nathans_Dad,
A misaligned ring and pinion will often destroy itself, mandating a replacement ring and pinion, which is in essence a full gearbox rebuild.

However, there's multiple things that could be causing the whine, as Pete Z. mentioned. In addition to the ones he said, there's also the possibility it's the throwout bearing. Does your reciept show a new TO bearing?

[Nathans_Dad]

Negative on the TO bearing but the only receipt I have is for the tranny pull and reinstall. The trans itself was shipped out for the rebuild and I don't have a receipt for that.

[KTL]

Another test for the T/O bearing is to depress the clutch just enough to put a load on the T/O bearing but not enough to make the clutch undetectably slip, changing the load on the transmission. See if that makes a difference in the whine.

You want to try isolating the T/O bearing load without substantially affecting the load on the transmission input shaft. Once you start reducing load delivered to the transmission, then you can't rule out the R&P whine because it's whiny note would typically change depending on load imparted to the R&P.

[gtBen]

Hej

Originally Posted by Nathans_Dad

I have noticed a whine coming from the transmission under load, usually between 2k-3.5k rpm. Doesn't happen when the the car is in neutral and the engine is revved to the same area. Doesn't happen when the clutch is depressed.

I think I had the same whine in my –78 SC and the trans was professionally rebuilt, and it was remarkably more in 5th gear then in the others.
This is what I was told:- the sound was most probably caused by low oil-level for some time during it’s previous life. When the oil-level is low it will affect 5th gear more then the others because 5th is the one on top. It is just a noise-problem, it will not directly affect the performance or lifetime expectansy. If you can’t stand the noise you have to put in new gears but it’s not necessary a problem with r&p and definitely not the throwout bearing.
I only drove my car for a very short time before rebuilding engine and trans and didn’t sort that out as a problem. Later on one potential buyer dropped out because of it and others that had some 911-experience didn’t care even though I mentionend it for them. It may even sound a bit racey …look at it that way

Bengt

[Peter Zimmermann]

ND; Has the whine become louder over the time that you've owned the car, or is it a characteristic of the car that's starting to bug you? I have to ask you because '80s 911s are not quiet cars, and I'm wondering that as you become comfortable with your car, you are noticing things that might have always been there.

I'm going this direction because different owners have different tolerance levels for noise, and there might not be anything wrong with your trans. When you drained the trans oil were you satisfied that it had enough oil in it? With the noise happening in 2-5, that means the cause can affect the gears in the center housing (2,3 and 4), as well as 5th, which is in the nose section. That, in itself, is very unusual.

When you state "under load," what do you mean? If you're attempting to use full throttle, or even 3/4 throttle, at revs that low, you're causing lots of stress (lugging) inside the trans, so the noise that you're hearing might be "normal." Your car is much better suited for full throttle use at rpms above 4,000.

[Nathans_Dad]

I was able to get a video of the whine. Excuse the camera work, I was trying to get the noise not take pretty pictures!

Turn up the volume to hear it right around :03.

[CCM911]

As for the whine, mine has whined for the past five years. I think they all make a bit of noise, but since I removed the sound padding from the engine compartment, I would think hearing a bit more noise is normal.

Is your sound padding still in the engine compartment?

[Nathans_Dad]

Originally Posted by Peter Zimmermann

ND; Has the whine become louder over the time that you've owned the car, or is it a characteristic of the car that's starting to bug you? I have to ask you because '80s 911s are not quiet cars, and I'm wondering that as you become comfortable with your car, you are noticing things that might have always been there.

I'm going this direction because different owners have different tolerance levels for noise, and there might not be anything wrong with your trans. When you drained the trans oil were you satisfied that it had enough oil in it? With the noise happening in 2-5, that means the cause can affect the gears in the center housing (2,3 and 4), as well as 5th, which is in the nose section. That, in itself, is very unusual.

When you state "under load," what do you mean? If you're attempting to use full throttle, or even 3/4 throttle, at revs that low, you're causing lots of stress (lugging) inside the trans. Your car is much better suited for full throttle use at rpms above 4,000.

I have only had the car about a week so I can't say if it is a new noise or not. It's something I have noticed during the "gettting to know you" period. I drove the car 8 hours home from where I bought it so I was able to hear all sorts of wonderful creaks and whines.

On a test drive today after putting in Swepco, it does in fact make the whine in 1st so that means it whines in all gears.

By "under load" I mean somewhere around 2k-3k rpm is where I notice it the most. It's fairly quiet so I can't hear it at higher revs.

[Nathans_Dad]

Originally Posted by CCM911

As for the whine, mine has whined for the past five years. I think they all make a bit of noise, but since I removed the sound padding from the engine compartment, I would think hearing a bit more noise is normal.

Is your sound padding still in the engine compartment?

No I pulled that out a few days ago, it was an aftermarket pad. I still heard it with the pad installed though.