Transmission problems

[harveyconnor]

Hey all,
Not sure how to describe this but I have an issue when accelerating in my Vf sv6 Lfx auto transmission.

Whenever it is changing gears and accelerating the car sort of jolts and feels really clunky when automatically changing gears.
Not sure what this is called, and how I can diagnose and fix it.

cheers

 

[NJD-1992]

Sounds similar to either of these scenarios?

2015 Holden VF Commodore: clunk when shifting between drive and reverse

General Motors issued a service bulletin for 2015 Holden VF Commodore vehicles that had six-speed 6L45 MYA automatic transmissions. In these vehicles, a 'clunk' or 'ping' noise may be heard from the rear of the vehicle when the driver completed a 'change of direction shift' (i.e. drive to reverse or reverse to drive). The service bulletin attributed this noise to movement between the splines of the output shaft and the output flange. Furthermore, this noise could 'propagate' up the prop shaft and the transmission tunnel to the rear of the vehicle. To fix,

• The propeller shaft was to be removed;
• The transmission output nut and flange were to be removed, and the output shaft flange nut discarded. The transmission output flange was then to be removed from the transmission output shaft;
• The output flange and shaft were to be inspected for corrosion and, if present, that corrosion was to be removed with a wire brush. The parts were then to be cleaned with Prepsol, wiped thoroughly and allowed to fully dry;
• The output flange was to be re-installed with adhesive (GM part number 89021297) or Loctite 272 applied across the width of the flange splines. Once adhesive had been applied to every spline along its complete length, the output flange was to be installed over the shaft. Excessive adhesive was to be wiped off with a clean rag;
• The new output flange nut was to be cleaned (with Prepsol if required);
• The output flange nut was to be installed with adhesive across the thread of the new nut;
• The propeller shaft was to be re-installed; and,
• The vehicle was to be left for 24 hours so that the adhesive could cure.

Holden VF Commodore with six-speed auto: clunk noise on take-off

General Motors issued a service bulletin for Holden VF Commodore vehicles that had six-speed automatic transmissions. When accelerating from rest under light to medium throttle, the driver may notice a 'thud' or 'clunk' noise from the rear of the vehicle immediately after take-off. According to the service bulletin, the noise would only be heard when moving forward in Drive mode or Sports mode, but would not be experienced in Active Select (A/S) mode.

The clunk noise was attributed to the transmission making a clutch change while in first gear. Specifically, the transmission changed from a first locked (CBR1 clutch locked) to a first freewheel (CBR1 clutch released) state at 4 km/h. The driver does not usually feel the clutch transition of CBR1 releasing since the first gear ratio was maintained. However, the disengagement of the CBR1 clutch and the engagement of the one-way clutch caused a torque-spike that could produce a clunk noise at the driveline end of the vehicle.

According to the service bulletin, owners were to be informed that the noise was a 'known, normal characteristic of the transmission' and that it was 'not detrimental to the life of the vehicle'.

Have certainly felt the second scenario in my 2016 (Dec 2015 Build) SV6 with auto.

 

[hjtrbo]

2 things you can do easy off the bat.

Get a OBD2 dongle and any smartphone app and scan for codes. Take a screen shot, reset DTCs, then go for a couple of drives over a couple of days. Then read again. The second round of codes are genuine.

Check transmission fluid level.

Not a direct answer but will get you heading in the right direction.

 

[gossie]

How many kms and when was it last serviced professionally?

 

[harveyconnor]

How many kms and when was it last serviced professionally?

Standard service every 6 months only a month ago. 93000km on the clock currently.

 

[harveyconnor]

Sounds similar to either of these scenarios?





Have certainly felt the second scenario in my 2016 (Dec 2015 Build) SV6 with auto.

Definitely experience the second one but that’s not the issue I’m having. It’s a weird jolt, there’s no sound or noise

 

[harveyconnor]

2 things you can do easy off the bat.

Get a OBD2 dongle and any smartphone app and scan for codes. Take a screen shot, reset DTCs, then go for a couple of drives over a couple of days. Then read again. The second round of codes are genuine.

Check transmission fluid level.

Not a direct answer but will get you heading in the right direction.

How can I check the fluid level? There’s no dipstick

 

[Forg]

Standard service every 6 months only a month ago. 93000km on the clock currently.

I don’t think the standard services involve doing anything with the gearbox before those sorts of km’s.
I reckon first thing is get someone to replace/flush the fluid, replace the filter, and do whatever else they do when servicing gearboxes; even if it doesn’t fix your problem, it’s probably a good idea at this age/distance and takes a potential cause off the table.

How can I check the fluid level? There’s no dipstick

The results of my Googling seem to give instructions that are best performed on a hoist; I reckon just get the gearbox serviced & see if that fixes it, and you’ll know the fluid’s at the right level & whether it needs some form of attention on the electronics front.

 

[gossie]

You need to have the GEARBOX serviced properly at your local auto gearbox shop.