90 Jetta transmission whine

[coke]

Just curious what the experienced minds out there have to say. My 90 Jetta runs excellent, drives excellent. Real great deal for a grand. However, the transmission whines in it. Its not unbearable, by any means and hardly noticeable at highway speeds.

Of course, one of the first things I did when I brought it home was change the transmission fluid and filled with the appropriate amount . The noise is somewhat reduced but still noticeable. So, my question is what causes it? There aren't any adverse side effects such as hard shifting, grinding gears or syncros, or anything. Other than the noise, its flawless.

[82vdub]

It probably only whine's in 5th gear, correct? This I would attribute to 5th gear being run low on oil and the gear got hot. It's either lost it's heat treatment due to this, or the bearings/bushings or whatever it is that suspends the gear in it's proper orientation and mesh with other gears could have been damaged leading to a mesh with the other gear slightly off from what is ideal.

I've owned two Mk1/Mk2 VW's with 5 speeds and they both have the 5th gear whine. I have previously stated that I would consider any 5 speed Mk1/Mk2 trans to have a junk 5th gear in it when buying a transmission or vehicle with the 5 speed trans. It's my default position since my only two references all have this whine, meaning that 5th gear is compromised.

[coke]

No, whines in every gear.

[82vdub]

If the noise isn't gear related, then it's an issue with an output or input shaft/bearing somewhere. Did the whine show up after you changed the fluid, or was it always there?

[coke]

Always been there. Since I picked it up. The crap that came out of the gearbox was stinky and black. Very dark colored. It seemed that most of it was in there ,nearly 2 quarts.

[TylerDurden]

I rekon it could still be a gear, or pair of gears... they are constant mesh trannys.

I changed my gear oil today. It also looked like used diesel motor oil and smelled a bit cooked. For all I know, it could be a decade old.

[coke]

Ditto. Mine was def old. I tried the ole Penzoil Syncromesh to see how it'd work. I've heard good things about it. I might change it out to straight GL4/GL5 80w90 gear oil, see if that quites it down. It shifts so great and other than the noise is the best transmission i've had in a Jetta yet. Disappointing.

[the man 53]

When I was younger and didn't know I put 80w-90 in one and it never shifted correctly. I later find out it is supposed to be 75w-90. I put that in and it shifted way better, but I think the damage was done as it didn't shift perfectly.

[Dakotakid]

A good friend of mine suggested me running a 50/50 mix of the GM oil and gear lube. Seems to be doing fine....has not been that many miles yet. The fifth gear housing end of the trans is weeping at the gasket. But, I do not think there is a correlation. I need to replace the gasket as soon as I can get to it.

Any body else running GM oil develop any leaks???

[coke]

You mean the Syncromesh? I'm running Penzoil Syncromesh same (profanity removed by moderator) as the GM stuff in a yellow bottle w/ a lower price tag)

I have no issues yet. I've only got around 5-600 miles on it though.

[Dakotakid]

Yes, the yellow-bottle Pennzoil Synchromesh.
The AGS trans shifts very well with no whines, bangs, clanks.

[coke]

Who knows why mine whines. I'm not concerned. It goes and shifts great, other than making a noticeable noise. Don't fix what isn't broke, right? Just wondering if anyone had any possible ideas on what might've caused it or something like that.

[joat]

does it whine worse when at a stop light ( clutch pushed in) ? even in neutral? if so , it might be the throw out bearing ( behind the green trans cap )

[coke]

No only when in gear and moving.

[jettaman8691]

I drained and re-filled my 5 spd the other day with Lucas tranny oil and auto tranny fluid. Sounds good and shifts fine, so far.