cossie2

Does anybody using ggr uprated diff mount as i am having off throttle rumbling noise on rear... but its not the exhaust or shafts which are new including the diff......
any thoughts would be great..thanks

Caddyshack

If in doubt take it off and gently run it to see what happens. Maybe the new diff wasnt set correctly?

What about the round centre bearing on the prop? And check the engine mounts, the drivers side one on a right hand drive car fails a lot (that might only be on the 4x4 model)

cossie2

Hi,
thanks for reply...well all the mounts are new vibratehnics and the prop shaft bearing also,maybe some 2000 km..i have checked all and replaced also front shaft cross bearings
...this is really driving me crazy as all is practically brand new.....only thing i didnt replaced is rear shaft cross bearing but this one it looks it cane be replaced or can?It defo looks different from the ones on front shaft.....
Rubber donut is also replaced....vibration sound only comes off throttle around 2 to 3000 rpm...pressing the pedal it disappears..really strange..
could it be oil in diff..right now is motul competition 75w140 LS?

Sierrasideways

iTrader: (1)

The diff mount bolts wouldn't be rubbing the rear ARB by any chance? Think I've seen countersunk bolts used instead of hex heads which stick out. I had to shave the bolts down on mine but it's 2WD. Just a thought...could be wrong!

Philip.

cossie2

thanks for input..did that one also...

lacey

Think someone on here had this problem before
And it turned out to be the diff noise going through the shell via the mount as it is far
More solid than the std one

cossie2

thanks..so better to get the oe one than

Marc sierra

iTrader: (1)

Do you also have a Vibratechnics mount for the gearbox? It is adviced to keep that mount standard because it apparently adds a lot of vibration if changed for an uprated mount.

MONSTER

Deffo, I added a vibratecnics g/box mount and the rumbling I got through the cars was shocking.


O/P, take a look n see if the bolts holding the mount to the diff aren't fouling the ARB, it's a common problem. I ended up machining a new end plate for my mount that accommodated countersunk bolts, it's still close but it doesn't touch any more.

cossie2

ye..all vibratehnics are under car.......well to end the story..i couldn't believe it..stopped at petrol station and added some air in rear tires....result.. no more sound from the back off throttle....i pumped them till 2.2 bar..than i released them till 2.0 bar for check only.. again same story so filled them again to 2.2 bar...all quiet..go figure..anyhow thanks for replies...