Gearbox whine

[CazzaVR 0]

Yo! I've just had my gb rebuilt with a 3.68 fd. The guy left most of the bearings as he said they were fine. I also changed the gb mount for a solid rubber Golf one. There is a whine- very noticeable from 3k onwards in first gear. Barely notice it at all in 2nd and not at all in the others. Could this be due to the mount? Anything to worry about? He's offered to fit the bearings with no labour charge, but it's huge hassle to remove the box again...

 

I don't know the history of the box I used for the rebuild, however it was very clean inside and worn parts were replaced.

[Kevin Bacon 5]

Nothing to worry about and the whine comes from the diff / gears, not the bearings ;)

[davidwort 0]

so is it the diff that starts to whine mainly on old 02A boxes then? I've never really heard bad ones, unlike the old mk1/2 020 boxes that could get terrible

I've one that's almost totally quiet at 150K the other is starting to get a little whine mainly when you're off the power

They seem pretty strong boxes though, don't really hear of them failing completely even when old and abused.

[CazzaVR 0]

Thanks Kev. Why's it whining then? Is it the mount? Mart (Hotgolf) seemed concerned when I told him.

[Kevin Bacon 5]

All gearboxes whine to a certain extent. You just don't hear it normally because the factory spec mount absorbs it. As soon as you move away from the factory spec rubber, it becomes audible unfortunately. It's perfectly normal.

 

If the gearbox doesn't crunch or jump out of gear, it's fine. Noises come as standard with 02As :D

[Hotgolf 0]

Kev, in this instance I don't think it's gear noise, but either needle or input shaft bearings.

From the original text I had the noise of severe enough to warrant a call saying the noise was really bad in first, then maybe a hint in second.

When I built the box there was no real history, apart from there's about 100k on it. The build involved a final drive change, diff and output shaft bearing and a set of seals.

Everything 'looked' ok but as you know looks can be deceiving. Even the hint of discouration could be a failing bearing, which might have slipped by.

Having done a few champion ship cars and alot of track cars now running solid mounts on 02a/j/s'sI don't think it's a gear sound. What I've suggested is to change the mount over first. If its quiet, it's the mount, if not, it's the box. I've offered a full strip down to replace the bearings remaining it's just a bit of hassle taking the box out again.

 

This is the thing with box rebuilds though. I always say I won't do partial builds for this exact reason, especially on unknown boxes. If it makes a noise afterwards it always falls back on the person who built it even when warned this can happen, without fault of the builder. This is only the 2nd time too lol, but I've always honoured my work even if the fault lies elsewhere. Can't say fairer than that :)

 

---------- Post added at 9:16 PM ---------- Previous post was at 9:15 PM ----------

 

I will add my own boxwhines like a b1tch, but it is a 6spd quiafe dog box so it's allowed a little bark lol

[CazzaVR 0]

Definitely gonna try a standard/old mount (pretty sure I've got one). That will be a good indicator. Think I'll bring it back to you anyway Mart, for peace of mind.

 

Can't fault Mart's excellent service- always willing to pick up the phone/answer emails etc + the offer to fit the bearings FOC is very kind!

[Kevin Bacon 5]

Yeah can't say fairer than that at all! :D

 

It's hard to diagnose noises on a forum though. I do know that diff whine gets progressively louder the firmer the gearbox mount gets. But with each step up in stiffness, the gearshift improves! So as usual, it's a mixed bag of compromises and gains.

I've had my 203K old gearbox rebuilt twice over the years. First was just a general refresh, and then again when I had the Quaife and 3.68 FD fitted. On both times, the layshaft bearings have become noisy not many miles after the rebuild. This would be the familiar "rattling marbles" noise that goes when the clutch pedal is pushed down. That's what I meant about noises coming as standard with 02As :D They can make the noise for years and not cause any harm though.

 

Is the O2J any better? Was thinking of fitting an 02J from a Polo GTI onto my VR6 bellhousing so that I can use the dog bone mount. Is this possible?

[fla 9]

Just noticed a faint whine from my gearbox today. Tends to disappear when the clutch is pressed.

Maybe its always been like that and I've only just noticed.

I did change the fluid when I swopped the auto out but its always had a very slight drip from the bottom (vw) cover plate.

Anything to worry about? Also is there any way to check the fluid level? When i fitted the box it was easy as the box was on the workbench!

[Geeba 0]

Could be the release bearing Hasan... that it disappears when you press the clutch makes me think it could be.

 

Definitely worth doing the level though, my manual box is in a gazzilion bits but they are usually fill till it runs out.

[fendervg 29]

Just noticed a faint whine from my gearbox today. Tends to disappear when the clutch is pressed.

Maybe its always been like that and I've only just noticed.

I did change the fluid when I swopped the auto out but its always had a very slight drip from the bottom (vw) cover plate.

Anything to worry about? Also is there any way to check the fluid level? When i fitted the box it was easy as the box was on the workbench!

 

There's no dipstick unfortunately, like what you might have on some auto boxes. As a guideline, the level should be at or just below the bottom lip of the filler hole - I'd say best to top it up just in case. If the noise goes away with the clutch down it's more than likely the release bearing.

[fla 9]

Thanks chaps. I'll have to get on to it before it gets too cold i guess, otherwise it'll be in Spring next year. Would be nice to have a heated car-sized garage with a pit or a ramp...

[fendervg 29]

Tell me about it - working outside in the cold and wet is no fun. Make sure you can get the filler plug out before you undo the drain plug.

[vw rule 19]

Also regarding gear oil the multi grade works best, especially in the winter helps stop notchy gear changes, which is an issue with these gearboxes, normally 1st and 2nd synchro's go first, that's what happened to mine so had it rebuilt back in 2009

 

Castrol Syntrans multigrade 75w-90

you'll need at least two 1L tubs.

I bought mine from Halfords.

 

The Allan key filler & drain plugs are the same size, think they're tapered thread which is why they don't screw right in.

 

Also when you're ready to refill the gearbox and drain plug is back in, you can remove the black plastic vent plug, it's behind the reverse switch on the left, it simply lift's off, and will push clip back on. Once vent plug is removed just fill up gearbox and have the filler plug removed, and keep checking to see when oil starts running out, the oil should submerge slightly the lower part of thread, hence thin slow trickle running out of filler plug hole.

 

Si

Edited November 1, 2019 by vw rule

[fla 9]

useful pointers Si many thanks.

[vw rule 19]

fla said:

useful pointers Si many thanks.

 

No worries here's a link to a thread from 2014 regarding the Castrol Syntrans multigrade 75w-90 gear oil.

 

 

Si

Edited November 3, 2020 by vw rule
Attached link wasn't working so has been changed/updated.

[fla 9]

i think you guys are on teh money with it being the release bearing because the gearchange is very nice and smooth with absolutely no crunching.

I'm just a bit ocd with noises and smells from the car!