Thread: High pitched whine in S2a gearbox

Do you own a dog?

I don't know much about these things, but it sounds like some sort of harmonic occurrence.

Are you running an overdrive with this gearbox? Does it only happen in 4th gear? How are the propshaft and output bearing?

John

Originally Posted by Johnno1969

I don't know much about these things, but it sounds like some sort of harmonic occurrence.

Are you running an overdrive with this gearbox? Does it only happen in 4th gear? How are the propshaft and output bearing?

John

Hi John, I had a thought along those lines, but not sure what might be source. As you suggest it only happens in 4th. Prop shaft uni’s are new, but I don’t know about the condition of the output bearing.

Cheers, Matt

Have you tried holding your foot against the Hi-Lo lever when it's happening ?
.W.

I suspect that it is caused by slightly less than perfect mesh of the transfer gears. The most likely cause of this is wear on the intermediate shaft and/or bearings, assuming there is no overdrive fitted. But another possibility is incorrect preload on the output bearings - ensure the nut on the output flange is tight.

However, it appearing at specific speeds is almost certainly something is resonant at those speeds. one of the likely suspects is the red knob lever having lost its anti-rattle spring on the ball, or the gearlever due to wear on the ball or a loose support. But it could also be a loose body part that is resonant.

Hope this helps.

Originally Posted by drfish

Hi John, I had a thought along those lines, but not sure what might be source. As you suggest it only happens in 4th. Prop shaft uni’s are new, but I don’t know about the condition of the output bearing.

Cheers, Matt

Hey Matt,

Maybe just have a quick squiz at the output bearing. With the gearbox and transfer both disengaged and the handbrake off, grab the handbrake end of the prop and give it a jolly good shake to see if there's much play there. Aside from the various possible causes being suggested here already, maybe also look at anything in the alignment or mounting of the transmission or the possibility that the noise is occurring in another associated component of the car.

I'm sure that people will keep chipping in with ideas. You'll get there.

Cheers,

John

Thanks for all the input on this problem guys. I’ll check through the items in these replies next time I drag the old girl out, and report back.

You can get problems with bearings that come and go at certain rpm, used to get it with wheel bearings that were a bit past it.

Does the whine happen all the time or under load or coast in 4th.

I did wonder about the synchro on 4th, but think it’s more likely to be a bearing, especially if it’s continuous.