BONK/CLUNK NOISE VF SV6 automatic 2016

[VT2Commie]

It is NOT a mandatory recall or "flagged" with anything to do with warranty.

It was realeased as a TSB (Tech Service Bulletin) only a suggested diagnosis path. This "holden dealer" I'd say isnt interested or has no GM trained service staff left. And if they do they don't have a clue. Which is very unfortunate.

 

[Jasonjohn]

It is NOT a mandatory recall or "flagged" with anything to do with warranty.

It was realeased as a TSB (Tech Service Bulletin) only a suggested diagnosis path. This "holden dealer" I'd say isnt interested or has no GM trained service staff left. And if they do they don't have a clue. Which is very unfortunate.

I’m at my wits end. Been to 4 mechanics and a dealer and still don’t know what’s causing this clunk in my gearbox honestly don’t know what to do and am getting more and more stressed over it. Dealer says to send car off to transmission shop that they deal with to do a trans rebuild. Which would be $5000 when I’m not even sure if it is the transmission. Even if I show them the bulletin I doubt they’ll do anything . Charged 170 for today to only be let down again. What about the next dealer i go to. To do the same thing.

 

[NJD-1992]

This "holden dealer" I'd say isnt interested or has no GM trained service staff left. And if they do they don't have a clue. Which is very unfortunate.

Right on the money here. Most "dealers" probably wouldn't even know how get into the system anymore.

As we have said, print the document out, walk into the dealer, and tell them you need this GM SANCTIONED procedure performed. The nut was only $30ish from memory, and the specific loctite was $50ish from Sydney Tools. Buy the Loctite yourself and bring it along.

 

[Jasonjohn]

Right on the money here. Most "dealers" probably wouldn't even know how get into the system anymore.

As we have said, print the document out, walk into the dealer, and tell them you need this GM SANCTIONED procedure performed. The nut was only $30ish from memory, and the specific loctite was $50ish from Sydney Tools. Buy the Loctite yourself and bring it along.

I called another dealer explaining the procedure. They found the garage clunk procedure & said i shouldn’t be hearing any metallic donk noises while driving only the “reverse to drive and vice Versa clunk” so they said it may not even be the issue. One transmission shop said to me yesterday if I’m hearing clunks while driving and clunks in the gearbox when changing gears then most likely the transmission is failing. I’m taking it to a transmission shop next week .

 

[VT2Commie]

Trouble is you aren't JUST driving along are you. You've stated the donk noise is when you yourself is on and off the throttle.
No slipping and gear changes are normal.

Some here have stated you may have two concerns, we've suggested the easiest fix, and go from there.

 

[Jasonjohn]

This noise is a metallic donk noise for sure coming from the transmission output flange spline free play.

"Glueing" the transmission flange with adheasive (Loctite 272) as outlined in the TSB @NJD-1992 and @Skylarking have pointed out in their above posts will confidently fix your issue.

Update: Have had the transmission rebuilt. The drums were cracked and the thermostat was leaking. Clunk from reverse to drive and drive to reverse is gone, but there is still some time of backlash when changing gears from p to d and vice versa. Mettalic clunk noise still happening occasionally on and off the throttle. Trans specialist says it’s diff backlash. I had the car taken to a diff shop 2 months ago and he said there was nothing wrong with the diff so I’m not sure what else it would be .

 

[wetwork65]

Update: Have had the transmission rebuilt. The drums were cracked and the thermostat was leaking. Clunk from reverse to drive and drive to reverse is gone, but there is still some time of backlash when changing gears from p to d and vice versa. Mettalic clunk noise still happening occasionally on and off the throttle. Trans specialist says it’s diff backlash. I had the car taken to a diff shop 2 months ago and he said there was nothing wrong with the diff so I’m not sure what else it would be .

Thanks for the update.
For interest, how much was the rebuild?

 

[Jasonjohn]

Thanks for the update.
For interest, how much was the rebuild?

$4800

 

[hademall]

Update: Have had the transmission rebuilt. The drums were cracked and the thermostat was leaking. Clunk from reverse to drive and drive to reverse is gone, but there is still some time of backlash when changing gears from p to d and vice versa. Mettalic clunk noise still happening occasionally on and off the throttle. Trans specialist says it’s diff backlash. I had the car taken to a diff shop 2 months ago and he said there was nothing wrong with the diff so I’m not sure what else it would be .

It still doesn't seem like a satisfactory fix to me. What are the drums? And did they give any explanation as to how the drums crack?