VS shuddering at 60km/h

[Denno]

Hey all

My mums VS Commodore has this really annoying shudder when aproaching around 60km/h. Its an auto and I think it happens as the car gets towards the top of third and into fourth. It shudders really bad, then when it changes to the gear up, its back to normal. And when I say normal, that not exactly a good thing either. While driving the car, it is always vibrating. I can feel it pretty bad through the steering wheel, but it is most of the car that vibrates aswell. We have taken it to see a transmission bloke, and naturally when he took it for a drive it didn't shudder, but it did vibrate. He suggested that it was an engine vibration. We have had a new transmission put in, and mum thinks the shuddering started when we did get the new one put in, but Im not sure. I must admit, when i first started driving, I did drive the car a little too hard, but I have stopped doing that now. Mum and I both have different driving styles, she is fairly slow of the mark and I drive it a bit quicker (I don't thrash it) but it still happens to both of us. I know this is alot of stuff to take in, so I thankyou for taking to time to read this.
After all that, here is my question. Does anyone know what the cause may be, and how it can be fixed?
Car Details: 1997 VS Commodore roughly 130,000 kms done, as I said, new transmission a year or two ago.

Once again, thankyou for taking the time to read this.

Luke

 

[fitzy2005]

try searching for " Shudder " losts of posts on it,, prolly a wheel balance alignment uneven tyre pressure or even a egg in the tyre etc good luck

 

[dean2]

maybe a harmonic balancer, it depends on the shudder though

 

[Denno]

Nah, I know it isn't sumthing simple like wheel ballance or uneven tyre pressure, our mechanic has had a look at all that sort of stuff. Keep the ideas coming though please.

 

[blue alliance]

Seen it in the pos fords at work a couple of times. Think the gearbox isn't kickin down properly and it's stayin in top gear at low speeds and it just shudders like crazy. Haven't got the fords at work fixed yet so don't know how to fix. Will get back after they get back from being worked on. Is your car an auto, try clickin back to 3rd or what ever, see what it does.

 

[fitzy2005]

a gearbox mount then

 

[Moo]

What about tail shaft? Tight or worn uni, or centre bearing collapsed? Does it come through the steering wheel or through your seat? Is your gearbox mount broken or perished?

 

[Denno]

blue alliance - its an auto, clicking back to third doesn't make any difference.
Moo - It comes through the steering wheel. Tailshat, tight or work uni and the rest, i wouldn't not have a clue, I am taking note of everything people mention in here so I can get them check out.

Thanks for the help so far, please keep it coming.

 

[Don Sutton]

If you rev the engine slowly (in neutral with hand brake on or in park) taking it up through the range where you experience the problem while driving does the engine vibrate? If yes then could be out of balance torque convertor.
There is an inherent vibration on this model commodore from the driveline when accelerating which appears to be a driveshaft harmonic. I have heard of people removing the 2 piece drive shaft and replacing with a one piece custom made. Some vehicles have weights bolted to the extension housing of the transmission to cure this. This was done on chrysler valiants as standard and as a mod to XC and XD Falcons also. Check that the mounts are around the right way and that if mounts were replace they are the correct ones and are in good condition. Driveline vibration is caused by a phasing difference caused by uneven universal angles at each end of the drive shaft and the use of weights adds inertia to the gearbox which counters this. Do the obvious things like checking the condition of the joints paying particular attention to the centre CV joint that it is not brinelled. Good luck.

 

[raZel]

go and get your wheels alligned, quite often you jst clip a gutter or something minor like that and it creates a vibration at a certain speed... i had it at 80km/h and i got my wheels done and it fixed it perfect, let me know how u it goes...

raZel :thumbsup: