Hey all....maybe I am just hyper sensitive but I think I am hearing my transmission while I drive.....maybe just a little too much. Could just be normal. Anyone know of a super quieting tranny oil? I think I am using Stalube 85-90 or something like that. Thank you very much.
gg

Call me crazy , but putting 5 drips /ounces of
Marvels mysterious oil in there ,from time to time

Seems like the way to go

[quote name='second wind' date='Dec 10 2018, 12:54 PM' post='2672780']
Hey all....maybe I am just hyper sensitive but I think I am hearing my transmission while I drive.....maybe just a little too much. Could just be normal. Anyone know of a super quieting tranny oil? I think I am using Stalube 85-90 or something like that. Thank you very much.
gg
[/quote

What type of sound - 1) low frequency growling/grinding or 2) high frequency whining?

You can't fix a mechanical issue with a fluid you'll only make the damage worse in the long run

Wouldn't hurt changing it, it may be low and that is what the noise is. The cost is inexpensive enough to try a different weight oil and see if that makes a difference for you.

There are hundreds of additive products on the shelf at your local FLAPS that will try to convince you that they will fix all sorts of problems.

Truth is, just make sure your tranny oil level is right, maybe even change it (especially if you are not certain that GL5 is in there). Anything beyond that and it needs some maintenance, not a magic BS treatment.

[quote name='914Toy' date='Dec 10 2018, 01:51 PM' post='2672801']
[quote name='second wind' date='Dec 10 2018, 12:54 PM' post='2672780']
Hey all....maybe I am just hyper sensitive but I think I am hearing my transmission while I drive.....maybe just a little too much. Could just be normal. Anyone know of a super quieting tranny oil? I think I am using Stalube 85-90 or something like that. Thank you very much.
gg
[/quote

What type of sound - 1) low frequency growling/grinding or 2) high frequency whining?
[/quote]

You know....that is the tough question to answer...no growling or grinding....kind of an intermittent high frequency whir.....like a mechanical device would sound normally....unless it isn't normal. I might be just hearing the tranny.....it isn't supposed to be absolutely silent, is it? I guess it has been two years since I changed it...maybe 6-7,000 miles.....thanks.
gg

Have you checked the transmission oil level? Let's hope it's something simple.

Had the same issue; time force visit to Dr Evil...

Could be, but I bet he would want some of the so far unanswered questions to be answered too.

OK....trying to quantify the sound.....maybe a whir whir whir whir whir and on a 1 to ten a 1......could be just normal....haven't checked level yet.....thanks you guys...tranny works perfect....a little premature for a rebuild....just asking.....
gg

PS My 914/6 in 1978 had a definite tranny sound and a spot of rust on the rear fender the size of a quarter.....PANIC!!!! sold it for $6,000.....bought for $4,000.....thought I made a killing....
gg

Once again: Have you checked the transmission oil level?

Will do and I hope you are right. No leaks though but I have seen enough to know anything can happen. Thank you.
gg

Actually, Rand's suggestion to check your transmission fluid level is a good idea for all of us.

I'm looking at mine soon!

Thanks

one issue is stalube is synthetic. these trans don like synthetic. change out to dino 80/90 gear oil. check your level, you will notice a difference.

I thought I used the old dino oil.....hypoid GL ....I forget which number....pretty sure not synthetic......I never buy synthetic for anything....gg

Use FIVE. If it's in question, I would drain it all and put fresh in. Besides knowing you have good fluid, it would also give you a chance to examine the discarded oil for any particles (hopefully small) that will tell you how the tranny has been wearing.

does clutch pedal being in or out effect it, parked or running? squeak etc could be throw out bearing, ask me how I know that one......

rear wheel bearing are ok?

you said in first post you used stalube 85/90. all the stabalube I see is synthetic. at $82.00 a jug, it is almost certainly synthetic. I just use tractor supplies hypoind gear oil 80/90. cheap and never a problem.

When do you hear the noise? Is it worse at a given speed or in a certain gear? Does it change pitch? If yes, under what circumstances?
When the sound is present, does it go away when depressing the clutch or when putting it in neutral?

I am going to recheck on my next drive....really soon. I appreciate all the help. Front wheel bearings are fresh but I will check.....rears are old but have been fine....I may just be hearing the normal noise of the car functioning....I will really focus and report back....plus check level and switch to dino oil for sure....see what happens....thank you all very much.
gg

I’m using valvoline high performance 75 - 90w gear oil. What do the 914 GODS think of this product. 64k on my tranny. Oh no I said tranny someones going to jump on that!

I don't get it...please 'splain.....
gg

Hey!! I got it.....politically correct not......well......not everyone loves Porsches.....
gg

And why is synthetic gear oil bad for a 914 trans?

Greg W.

Below in my signature is a link to several pages of notes. I go over all of the answers to the questions asked, and the possible faults.

Short answer for oil, these boxes lasted 30+ years on neglect and dino oil. You really dont need to spend more and you will not get improvement. Simple GL5 80-90w is all the factory recommended and I use the cheap stuff. Synthetic tends to be too slippery and our boxes work on friction. Also, fancy oils tend to have fancy emulsifiers and detergent packages included with them. This is not necessary and can actually, in my opinion and experience, cause harm over time (read my notes for more details).

As for noise abatement:
IF your box is in good shape, just tired, you can substitute a qt of Lucas oil stabilizer. I use this for assembly lube on my builds because it is as thick as honey and stays on the bearings to assure that they are lubed from the first turn of the crank. This is the stuff they sell everywhere and has the cool little display with the gears showing the lube crawling up the gears v not doing so with the regular oil. Used in over a hundred builds and was actually a tip passed down to me from an experienced Porsche mechanic (which is why I was no hesitant to try it). It will get rid of high pitched whines due to wear over the decades. Also, keeps lube locked into the bearings which sit outside of the oil bath.
Eventually, though, you will need to open and inspect bearings and R/P health.

Great bit of info re the Lucas.

Ok.....I bought two quarts of simple GL-5 80-90w amd a quart of the secret ingredient Lucas Oil Conditioner. Why does it say "for use in non-synchronized manual transmissions" on the back? Aren't 901 transmissions synchronized? What up with this statement? I know this is typical 914 'er over thinking....but I like it. Do tell...thank you very much.
gg

On the back of the Valvoline oil that is....
gg

Dunno. Keep in mind that the oils you buy now are not considering the intricacies of a 40yo Porsche transmission when making blanket statements. You will see that GL5 is also not recommended for transmissions with "yellow metal" in them, which ours clearly are, and GL4 is the preferred. The GL refers to the detergent and other additive package in there. The GL5 can stain the yellow metals of the shift forks and bearing housings, but this is not an issue in operation and the engineers at Porsche were well aware of this. As long as you stick to the weight, GL5, and no funny additives, you will be fine. It is when people try to outsmart the engineers and use really slippery stuff that their boxes get destroyed. I had one recently and I swear he used 10w as it was like water, clear, and smelled like fork oil. His box would not select a gear and this was why.

Thank you very much Dr. Evil....I am going to put in one quart 80-90 and then the quart of Lucas, then top off with more oil. Does that sound right? I was going to flush the tranny with starting fluid or something that evaporates fast just to get a fresh start.....you ok with that idea? Thank you again,
gg

Your oil, yes. Your starting fluid, no. Stop trying to get fancy.

Point taken.....thank you again...will report back....
gg

Hello Rand.....you were right...my tranny oil level was definitely low.....about an inch at least.....this time I will get enough in....and the good stuff....thank you very much.
gg

Looking forward to a positive report.

I always love the "Don't use synthetic!" comments with no actual data to back it up.

I've been rebuilding manual transmissions for close to 25 years now and I have not seen one actual test done to prove that statement. (If you bring up Bob the oil guy, go sit in the corner because the internet has beaten you)

I see all kinds of opinion statements like:
"It's too slippery"
"It's not compatible with old style syncro baulk rings / dog rings / blocker rings"
"It doesn't protect the bearings as well"
"The final drive will wear faster"

There are dozens of different formulations of synthetic gear lube just like there are dozens of formulas of organic gear lube.

While one may not work for your application, another may be way better than the organic oil you're running now.

If you want to see how your gear oil is holding up and what kind of wear materials are in it send it to Blackstone Labs. This will tell you the real story of what's going on with your oil. (works for engine oil also!)

When choosing a gear oil you need to look at how and what they are made with.
Base stock (Most synthetics here in the US use an organic base stock as you only have to be a % to legally be called synthetic)
Additive package (friction modifiers / stabilizers / sub stock)
Certifications / Compatibility per gearbox manufacturer

Lucas oil stabilizer is essentially a heavy additive package to try and fortify a standard oil. It works but in the end it is just a band-aid if you have a mechanical issue.

I've had very good results with synthetic in everything from Saginaw 3 speeds to Getrag 6 speeds. My go to is usually Motul Gear 300 unless there is a plated LSD internally then it's Motul Comp Gear. I use it because most of the cars I build see extended run time whether it's on the track or LA rush hour traffic where cooling is always an issue. In my testing and oil analysis samples the synthetic doesn't breakdown as fast due to heat as the organic oils I've tested.

That being said neither type will fix excessive wear or damaged parts.

Oh, and if you're whining about the cost of good gear oil, think about how much a trans rebuild is going to cost you.

Sure the good doctor is right as he is referring to the 914 trans which he must know' better than anybody,so whats the secret to Swepco ? which the 911 guys all say improves shifting ,etc in those transmissions,no one seems to mention use in the 914 box that I thought was rather similar in design .
Oil samples can't always be trusted ,last large vessel I ran had a massive gearbox failure due to worn out thrust bearing ,a recent oil sample showed no elevated levels of the bearing material in the oil,end result was a 6 month layup and around 1 million to rebuild it.

Our guys have rebuilt dozens of 915 boxes and only use the GL4 80-90 dino oil.

Some data is better than no data. If you do an analysis on a regular basis you should have seen something.

There is no secret to Swepco, I've run it and it's a good oil just super expensive for anything but race cars.

@mepstein have you tried Motul?

The customers might but ever trans at the shop gets the regular stuff. I wish I had the chance to watch Russo rebuild the 962 trans. Half the internals were titanium. I was busy with other stuff

So I drained my transmission and replaced with Valvoline 80-90 and a quart of Lucas Oil Conditioner.......I believe the sound has gone away. I was low on the tranny oil which could have been the issue, but having fresh fluid in there is a big plus. I also switched out my nylon shift rod bushing at the transmission with a brass one I had bought years ago. They call the metal "oilite" or something like that. I have been doctoring the original nylon bushings with aluminum tape and such to lessen the slop in the bushing, but this time I glued the new brass bushing in with JB Quik. My car has never shifted better!! All gears are like butter now. Fifth to fourth used to take a bit of a nudge and light double clutch....but now just a normal shift. All good on this end and thanks to everyone who offered their help.
gg