Help!!!!! Gearbox whirring noise.

[Steveb1980]

Hope someone can help with this.

I've had a 55 plate Monaro VXR 6.0 since May this year and have been getting a whining/whirring noise from the transmission tunnel area (I have already raised a thread on this ' http://www.pistonheads.com/gassing/topic.asp?t=140... '). The noise changes in pitch as engine revs rise and disappears when clutch is pressed or when stationary.

This last week I have had the gearbox taken off and inspected by a transmission specialist. The clutch looked like it had seen better days so I had this replaced with the LS7 unit along with the flywheel, spigot and also the propshaft centre bearing with hanger as the rubber bushing had perished. This did not remedy the noise so I had the gearbox taken out again and internals inspected.

Apparently everything in the gearbox is immaculate with no wear on any of the components and no abnormal noise from bearings etc. He did re shim the input shaft as there was play in it but no further action was taken. In a nutshell the guy could not fault it.

I have the car back and still non the wiser with my specialist scratching his head. The same noise is still there rising with revs but now it appears to be apparent at all times as long as the car is moving forward above 10-15mph (i.e. also when clutch is pressed and when coasting in neutral). When the clutch is fully depressed to the floor it sounds like there's a metallic scraping, not sure if this could be related.

I'm at a loss as to what to do next. I'm pretty sure it's gearbox related but as I've already spent a small fortune I'd like to see if anyone can throw any light on it before I get things pulled apart again. I feel I'm just throwing money at it at the moment.

Sorry for the long thread.

Thanks in advance and apologies for any poor spelling as I've done this on my phone.

Steve

[MatrixXXx]

I Have had a similar noise on my Auto from 5k (55k now) on the clock it seems to get louder when hot, with the bonnet raised it seems to come from the rear of the engine, sounds almost like a roller bearing running dry.

the only big bearing there would be the crank?, but they run run on white metal caps ?
can you take a sound clip?

[Steveb1980]

I can attempt a sound clip but not sure if the microphone would pick up the noise. Might give it a bash over the next couple of days.

[Black VXR]

From what I can tell from your post (and without hearing the noise, its a wild guess really), I had a very similar noise with my car (same car, same age).

Monkfish rebuilt the gearbox and the problem went away, apparently some bearings were worn which caused the noise

Are you hearing noises in all the gears or just some. I think my noise was worse in top gear

[Steveb1980]

The noise can be heard in all gears. I'm inclined to say it can be heard more so in 5th & 6th at dual carriageway speeds as the engine is around 2k rpm. As it the revs rise it tends to drown the noise out a bit.

Will try to get a sound recording in the near future.

I just want to be as certain as possible next load of money i spend on it is going to put it right.

Thanks for replies so far.

[MatrixXXx]

There is one way to identify the problem without having to dismantle anything , "Vibration analysis" we used to use it on big generators , each bearing has a specific resonant frequency , you can see noise from a bearing identify the speed etc , even pick up broken teeth on gears etc. we could even tell if a bearing was running low on grease and if it was the outer or inner race on its way out. the company who supplied the equipment was pruftechnik , , they might be able to tell you if there is someone in your area who might be able to help. its gotta be cheaper than tearing you transmision apart.

[Black VXR]

what part of the country are you in? I would suggest (if you can) you get a Monaro specialist to drive the car and tell you what it is. Monkfish are very good and based near to MK however I am sure there are other specialists depending where you are?

[Steveb1980]

I'm in Shrewsbury, Shropshire. I've thought about getting it to monkfish but its about 2hrs 30 mins each way so would mean time off work etc. if anyone knows of a specialist local to me I'm open to suggestions.

Thanks.

[Black VXR]

might be worth it in the long run - good luck - I assume you have checked the prop shaft centre bearing?

[Steveb1980]

Black VXR said:

might be worth it in the long run - good luck - I assume you have checked the prop shaft centre bearing?

You may be right. I had the prop centre bearing replaced as the hanger support rubber had perished at the same time as the clutch etc. I was hoping those items would solve my problems but I've still got issues.

[ARAF]

They're a similar distance from me, but for me it's worth getting up at stupid o'clock to visit them.

[Steveb1980]

Thanks, I'll certainly bear them in mind.

I've managed to get a couple of recordings of the noise although you may have to strain your ears a bit but it is audible (just).

First one is in 5th & 6th gear.

http://youtu.be/ehSu7ULhG6Q it changes pitch with rpm but the engine drowns it out at around 3k.

Second vid is in 3rd gear.

http://youtu.be/Ieuq0tOsCJU

Apologies for the shoddy camera work.

[MatrixXXx]

Sounds higher pitched than mine , mine also is louder outside the car, and its there just revving the car while stationary.

[Steveb1980]

To be fair it does sound a bit louder when driving. The microphone doesnt pick it up that well.

Can't hear it when stationary only when moving.

I've had a few mechanics in the car to see if they can come up with anything but nothing conclusive so far.

[Black VXR]

Are you sure its not the standard noise that comes up the gear stick

the fix is to take it off and fill it with silicone

[vxr2010]

Both my boxes make noise , it's difficult to hear on the clip the difference of road noise and gearbox noise , not your fault re noise , the rubber gear gaitor can go could it just be that ? If you mess around console area you should be able to see it if it's torn , boxes are noisy any way , if it's working and not too loud is it worth putting up with till it gets worse or does not work , when car is running parked up what does it sound like or is noise only in gear ?

[vxr2010]

I just read linked thread , I think it's very difficult to diagnose a box problem unless it's stripped down , maybe on a ramp it helps if area of noise is in one place , my spigot was seized on mine and box was making no more noise , when it was idling it made noise but no more than the other v8s

[Steveb1980]

Having never been out in another Monaro I'm unsure as to whether it is a 'standard' noise. I've had the gearbox stripped down by a specialist and he can not fault the internals.

I'll check the gaiter under the console to see if it's intact.

Cheers.

[throwyourbike]

I'm with vxr2010 on this.

Mine has made noise on and off since the day and hour I got it. 25k miles later it's still trucking and hasn't got any worse.

[vxr2010]

When I bought my cv8 I went to mf with the noise and was told it is normal , it still seems fine