VZ transmission / diff issues

[frankstonlion]

Hi guys - First post and hopefully someone out there can help me out.
We have a 2005 VZ 6V6 Commodore with a tick under 90k on the clock. Recently noticed that after being on the road for a while and when the car is fully wared up ( ay after a 10 - 20k drive) that when the car is slowed right down (like approaching a red light) or when put in reverse after a short stop, there is a vibration that goes through the car (feels like from the back). Took the car to the local Holden dealer who found nothing wrong with the transmission (so they did a 4 wheel balance and allignment?). Very next day (coincidence) the oil pressure swith carked it, and they fixed that, but the original problem remains - Anybody experienced this before or got any thoughts that I could take back to the dealer?

Appreciate any assistance.

Thanks

[andyman]

probably jus tthe slack in the driveline (dont worry there has the be backlash in there to work properly) going to reverse picks the back of the car up too so to speak with he irs, as the direction changes when you hit reverse it winds the suspension up a fraction,

i noticed when mine was auto it gives the car a slight jolt as the suspension travels the opposite way

[auke]

VZ StationWgn 2007 - Had a same/simular Diff clunking problem at low (slow) speed. Under waranty Holden removed diff and sent off to specialist. They took it apart but could not find anything and sent it back. Holden then tried/changed type of Diff oil and problem is now gone.
Check with Eagers Holden in Brisbane what oil they used because it solved the problem (12 months ago)

[frankstonlion]

Thanks for the reply will do

[frankstonlion]

Thanks for the quick response.

[Cod]

I'm also suffering from VZ driveline clunking, basically short of buying a new gearbox and rebuilt diff you're stuck with it. After taking it to a diff specialist he suggested flushing out the gearbox oil and putting in a high quality full synthetic oil so it copes better at high temps, i'll probably do that later. In the mean time he gave me a tube of "Shudder Fix" additive that seems to have helped a little. It may help you with your vibration problem, sounds like the little clutch that engages in the trans is slipping from hot spots. The shudder fix addititive is a friction modifier and helps with that.

Edit: Come to think of it now my car does the vibration too when putting in reverse, but to a lesser extent. I noticed it mostly when the car is cold though.

[frankstonlion]

Ok thanks for that I will also take that suggestion to the dealer

[bigdaddycool]

diff's do change character a bit with diff oils......... i run 85-145 on my lsd? ....... with lsd modifier lubricant stuff in it. works good...... my old diff i had 90 or something in it when I changed it from the stock service stuff........ but it wasn't as good as whatever was in it before.

i think thicker is better when it comes to diff's within reason.