Drivetrain sound??

[VR4 WRC]

Howdy,

The car has developed a nice new sound on lift off throttle the other day on way home from work.
I have a 1999 S2 Legnum Type S VR4 Auto.
On friday, as i was leaving work i had taken off "spiritly" across 4 lanes of traffic. Not stall up launch or anything, just a quick put the right foot down Then when got to the speed limit of 70 backed off the accelerator then heard a bad whine.
Stopped up the road thinking maybe did a CV joint. Couldn't see any problems with it. Got going again. Drove it home carefully. Everytime i backed off the gas the noise would be noticeable, but as soon as i touched the gas it would go away (my thought was transfer case when under no load).
Made it home (maybe 80km's).
Put it on stands Saturday morning but couldn't replicate the sound with the wheels in the air. Maybe not putting drivetrain under road resistance. Swapped the transfer case oil incase was low. Took a neighbour for a listening drive. It's slightly audible under acceleraton but still noticeable off the gas. He seems to think it might be the gearbox.
I tried to reverse it down out of garage to give it a quick degrease, but it start to feel jerky and "grabby" moving backwards and forwards at low speeds.
Does anyone have any suggestions? Just swap the box over or get a diagnosis to rebuild it. I am in the process of trying to sell it so i don't have a lot of spare cash to throw at it but i don't want to patch the problem for the next person.
Will pull filter from gearbox and maybe drain some fluid to look at it.
I will look at replacing transfercase first then if doesn't fix, look to gearbox.
To listen to attachment just rename file from txt to aac to listen to an audio recording from way home.

Thanks for suggestions in advance.

Scott

 

[TME_Steve]

Sure it's not rear diff? What happens rolling along slowly in a driveway or something?

 

[VR4 WRC]

It did sound like it was enminating from behind the dash (front of car). when moving it yesterday it was feeling grabby n jerky as moving down driveway. i can jack the back up as well n undo the 4 bolts for the tailshaft. Try to spin it n drop the oil.

Scott

 

[mills_88]

Sounds like the time I destroyed my rear diff. Dropping the oils is the best idea to get an idea of where it first though as trying to trace a noise is near impossible in these cars.

 

[VR4 WRC]

Have just dropped the oil out of the rear diff. Removed the tailshaft form the front of the rear diff. I rotated the rear wheels forwards and backwards. Rotated them opposite to each other. Stuck the pinky finger into the drain plug and felt the teeth on the gear. I couldn't hear or feel anything abnormal.
The oil didn't have any pieces of metal in it. Put the drain bolt back in and filled it up.
Now to start at the front end, but not anymore tonight.

Scott

 

[VR4 WRC]

Worked my way along this today. Had undone the bolts for the transfer case, wiggled the transfer away from gearbox, then remembered about trying to pop out the thru shaft from the passenger side. The top front bolt on the transfer case was a pain in the ass to loosen.
i had some trans fluid start dripping out from between the gearbox and trans case so i thought that i would drop some fluid out of the gearbox. Attached to the magnet of the drain plug is in the picture below. I'm sure that there is more in there somewhere.

Think it is now time to remove the gearbox & work on my options.

Scott

 

[TME_Steve]

Hard to see but that's not that much

 

[VR4 WRC]

Some more little pieces in the oil that came out. Will drop the gearbox out and see what else i can find and work out where they came from.

Thanks for help so far.

Scott