VT shudder

[MrE]

Ok, I'm a first time poster and this is the last avenue of hope I have to get answers on an aggravating problem with my VT II Commodore Wagon Automatic. You'll have to excuse the ignorance, I'm not a huge car person, but can hopefully explain things as technically as possible....

The problem is as follows;

The first problem is, it's an intermittent problem.

Upon driving around town or anywhere really my car 'shudders' at certain speeds and rev ranges. I've noted some of these speeds to be around 40-50km/h....about 80km/h....and this morning, the worst case at 90km/h and 100km/h.

Where I find it to happen mostly is under load...say for instance driving up a hill at around 50km/h in I would say 3rd gear....it's a very obvious shudder that I can feel through the steering wheel and the seat....when the car drops back a gear the shudder is still there but no way near as bad as when it's in a lower gear.

On the freeway...oh the freeway....what happens is I get to 100km/h and it's like a drone of a slow beating drum...if the traffic slows to say 90km/h it becomes this unbelievable shudder of epic proportions where the whole cabin is filled with this sound like when you have ur window down and u get that whopping sound...but only it's quicker.

These are the things I've done in an effort to eliminate the problem;

Changed the ignition leads (Thought it might have been a firing problem)
Changed the spark plugs
Replaced the Oxygen Sensors (This fixed a lack of power problem that accompanied the shakes - the car was fine for about 4 days or so after doing this, but then began to shake again)
All wheel balance and alignment

I've recently had it serviced and my local service station can not diagnose the problem - no fault codes come up on the computer. They test drove it but couldn't work out why it was doing it.

These are some of the things I've noticed and some of the things that have happened that may or may not be part of or have contributed to the problem (WTF.);

I ran out of fuel like 3 times in the space of a few weeks as my Distance to Empty readout and my fuel guage weren't working properly and shafted me big time. I thought that my fuel lines may have got crap in them, but the filter was cleaned out at the service I had.

Sometimes the autotrans doesn't pick the right gear, I'll put my foot down and it'll hesitate for a while and then unexpectedly drop back and catapult me into oblivion.

At idle at traffic lights or wherever, sometimes...this one's hard to explain...but it's like it drops in revs or something...like it's had a very brief power failure but then resumes normality (or normal abnormality).

The only thing I haven't had for some time is an auto trans service. Personally I thinking auto trans problem or even a computer problem...but I thought this would appear as a fault code when hooked up to a computer?
When I had my wheel balance and alignment, the guy had a look at the driveshaft bushes (?) and the rack (?) and said it all seemed fine.

I really am at wits end with this prob, it's driving me crackers as I am trying to get the car to a sellable state!

Anyway, I thought I'd throw this one out there and see if any of you can help. Any tips or suggestions would be greatly appreciated...

Cheers

[accentstencil]

I'm thinking transmission problem also. Have you checked the fluid level? There are fault codes for the transmission but they don't cover every problem.

[VT-565]

Check the transmission mount also, would explain the shudder going up hills.
Tailshaft ok? centre bearing?

[pablo]

I was going to say tailshaft universal joint, but you say these have been checked. I would take it to a Holden dealer to check out the transmission.
BOL, Paul

[randomroen]

yeah this sucks... you've described exactly the same thing my VTII is doing...

as soon as I get some money I'll get it looked at by holden...

[Indy_387]

Just throwing it out there...

But engine mounts perhaps???

[MrE]

Just took my car down to Bob Janes and asked one of the guys there to take it for a drive. He said he's 90% confident it's the centre bearing which would eliminate the take-off shudder....

So...will book the car in to get this done and see if it helps, will post the results....