Whining Gearbox

Have you checked the gear oil level?

Consider changing the oil and look in the old oil for signs of trouble.

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----------------------------------------------- Jim Adney snipped-for-privacy@vwtype3.org Madison, WI 53711 USA

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Have checked the level and that is OK, will probably have a go at changing it this weekend.

Somebody said they thought it might be an input shaft bearing? Just seems strange that it is not doing it in all gears just 1 to 3.

Thanks

Andy

Okay, I don't think I caught on completely at first.

For each gear (1,2,3,4) there are actually a pair of gears, one on each of two parallel shafts.

For each of these gear pairs one of the gears is fixed to it's shaft and the other is allowed to rotate on the other shaft. It rotates on a set of needle bearings.

When you shift into a particular gear you actually lock the "free" gear to its shaft so that it's bearing is no longer doing anything.

Since your gearbox whines in all gears except I wonder if it indicates a problem with the needle bearing inside one of your 4th gears.

Does it also do it in neutral? (Gearshift in neutral, clutch pedal up)

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----------------------------------------------- Jim Adney snipped-for-privacy@vwtype3.org Madison, WI 53711 USA

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No it does not whine in neutral, clutch pedal up or down.

It whines in 1,2 and 3 and is nice and quite in 4.

It whines under accelleration but not if you ease of the throttle and coast or decellerate.

So to my thinking it should be something to do with just those three gears and not the whole gearbox, but I could be very wrong.

Thanks

Andy

Even if you rev up the engine? If it never whines in neutral then it can't be any of the needle bearings that I was thinking of.

This makes it seem more like a differential problem, but I don't know why it would be quiet in 4th

It's unlikely to have 3 different things fail all at once. We need to look at what these all have in common. If you look a the way the gearsets are set up in the transmission you will see that they are in order with 4th at the front and 1st closest to the differential.

When a gear is engaged and is transmitting torque there is a force on their 2 shafts pushing them apart. In the VW transmission there are 2 bearings on each of these shafts, one at each end. In 4th, most of the force would be taken by the front bearing while in 1st most of it would be taken by the rear bearing. 2nd and 3rd fall in between. It's possible that you have a problem with one of the rear bearings, probably the rear mainshaft bearing because the rear countershaft bearing also supports the differential pinion and that sees a lot of force in every gear.

Reverse is right next to 1st. Do you hear the whine in reverse?

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----------------------------------------------- Jim Adney snipped-for-privacy@vwtype3.org Madison, WI 53711 USA

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No it does not do it if I rev the engine.

It does sort of whine in reverse, but I assumed that was because it was non syncro?

This kind of makes sense now, as someone else said it could be a bearing on one of the main shafts, but it puzzled me as to why it did not do it in 4th but your explanation sort of un puzzles it a bit.

Is these sort of bearing's changeable or is it better to look for a replacement gearbox?

Thanks

Andy

Maybe, I can't say, I have only had it for 2 months and at the time was told that the whine was not a big deal and that the bus would could run for

5-10,000 miles before it would need attention, it's just the noise is starting to be a pain round town, although long journeys are ok as you are in fourth a lot. And also I would like to know the cause of the noise for my own peace of mind.

The fourth gear, has much finer teeth, in order to whine

Think I will try changing the gear oil, as I am going on a trip next week.

Will have to have a dig around the UK to see what or who I can find.

Thanks

Andy

Okay, then my bet is on the rear mainshaft bearing, but my opinion means little on transmission questions. I've torn several down and only put one back together. That one went another 100kmi, however, before the car it was in rusted out.

VW gearbox work is very specialized. I think this particular repair might not be TOO bad, but in the end you might well wish you'd just picked up a junkyard gearbox. Unless you think you'd enjoy the challenge, I'd recommend that you check junkyard prices first.

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----------------------------------------------- Jim Adney snipped-for-privacy@vwtype3.org Madison, WI 53711 USA

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This is the same as what I have been told by someone else, so I am guessing that it is probably the problem.

Think I will go down the replacement box route. I can the always strip the other one to have a look and keep my bus on the road.

Thanks for your help.

Andy