Problem with VX

[acarmody]

Hi all, I was driving down the highway today (for once with my stereo off and window up) and I noticed a slight noise from the car. I was doing 100km/h at the time. But as the speed got up to 110km/h the noise got louder, at 110km/h it sounder like bass from a woofer (but not a loud) and the car started vibrating (courtesy lamb, loose stuff in drink holder, glovebox) again like my car with a sub going. So I went back to 100km/h and the noise faded again and stuff stopped vibrating, but the noise was still there but fainter. I wouldn't know how long the noise has been there because I usually drive window down and music up.
It almost sounds like the noise is behind the driver. But I have never had problems with the diff before. And only bought it a year and a bit ago (its a VX V8 3.45 diff, secondhand, low kms). I know my gearbox will have to be reconditioned soon as its playing up a bit (slower gear changes, light noises, etc) but I wouldn't think it would be it. Though the other day while driving on the highway I flicked the gear selector into 3rd so i could overtake a car in front and it took a bit over 1.5 seconds to change gears.

This has me stumped and also feels expensive. Any info you guys might have would be greatly appreciated.

-Adrian

[azkwazere]

Wheel balance?

Trans might need a service by the sounds of it too..

aZk.

[acarmody]

Wheel balance?

Trans might need a service by the sounds of it too..

aZk.

I don't think it needs a wheel balance as I had my suspension all replaced last month with a new camber kit, and I though they did all that. Even so I get my wheels serviced every 10,000kms.

And the transmission need a reco or replacement soon. Service was done not long ago, and they said they found some metal in the filter and pan. But she still runs alright except slow gear changes, and possibly this.

[ACEMonkey]

If your steering wheel doesn't vibrate excessively or lean to one side, your wheel balance is fine. I'd suspect you have noisy tyres or you've over pressured your tyres. You can either reduce the pressure in your tyres (within safe limits) or go for softer tyres if you want a quieter ride.

Try resetting your computer and see if that helps with your slow transmission.

[acarmody]

Thanks for all those who posted. I have found the problem with the car. I managed to find time to look under my car, and it took me all of about a minute to find the problem. One of the bolts from the tailshaft to the diff was out, and I don't mean loose, I mean it was being held in there by gravity. there are only 3 bolts holding the rubber coupling together and 1 is out. Man did I swear my head off when I saw that!!!

Took it straight to the mechanic as I didn't have a right socket to do it up (some sort of weird star type bolt head).

All good now.

Thanks all.