Universal joint questions??? Am I on the right track???

[Not_An_Abba_Fan]

Hello again Not-An-Abba-Fan. Could the noise of a dry centre bearing possibly be mistaken for a diff problem noise by two mechanics?
I only ask this because I've just got back from another mechanic's today. He's been recommended by a few friends of mine and this is what happened.
Took it for a quick drive and did all the usual tests, swerving side to side, accelerating, cruising, decelerating etc.
While all this is happening he's telling me it's hard to diagnose noises like this. “Don’t know…could be any number of things”. But then at the end of the test coming back he says “yeah… I think it’s the diff”… but he didn’t sound really sure.
His advice was to keep driving it. If it gets worse it will be easier to pick where the noise is coming from. Also to add a $15 tube of Nulon G70 to the diff oil and see if it makes a difference.
I’m off to do that right now.

And he said this after you told him it could be the diff?

A test to do, but I will warn that it can be dangerous if not done correctly, is to lift the rear wheels off the ground and support the car with axle stands, chock both front wheels, have someone in the car and start it up and put it in first. Let the wheels spin and using a screw driver as a stethoscope, put it against the bracket that holds the centre bearing and see if it is noisy. It will be very pronounced through the screw driver. You put the metal tip on the bracket, and then put your ear on the end of the handle.

 

[SavVYute]

And he said this after you told him it could be the diff?

A test to do, but I will warn that it can be dangerous if not done correctly, is to lift the rear wheels off the ground and support the car with axle stands, chock both front wheels, have someone in the car and start it up and put it in first. Let the wheels spin and using a screw driver as a stethoscope, put it against the bracket that holds the centre bearing and see if it is noisy. It will be very pronounced through the screw driver. You put the metal tip on the bracket, and then put your ear on the end of the handle.

LOL No. I didn't mention the diff at all. Not that silly. But he did see the little service sticker the first place put on the top of the windscreen, as soon as he got in the car.
First thing he said was "what are you doin goin' to those rippoff B......'s down the road for? Must be one of those things mechanics notice. I didn't even see it until later, and wondered how he knew I'd gone there.

And thanks Not-An-Abba-Fan for that advice. I'll try that and I'll make sure I do it safely when some friends come over.
Yeah.... I don't want a car dropping onto me or a screwdriver getting driven through my scull.

:idea3:

 

[SavVYute]

OK I've jacked up the ute with a couple of mates and got under it while running and in gear up to about 60+kph.
#@%* that takes some courage. Or stupidity to do HA HA. Don't know which. Anyway I can tick that off my bucket list.

Theres so many mechanical noises under there its really hard for me to tell. Maybe the diffs not loading up enough to be sure.
So thats decided it. She's booked into to the specialists next week.

And guys I don't recommend doing what I did. Too #%@**# dangerous; and since I did it I've heard so many stories about cars falling on people:undead: its not funny.

I'll keep you posted.

 

[Not_An_Abba_Fan]

No need to get it up to 60 though.....just idling along in first to make the tail shaft spin would have been enough. I have done it too many times to count, and if it's done with care, it's perfectly safe.

If the car didn't fall on you, you did it safely :spot on:

 

[SavVYute]

Now you tell me!

 

[Chrispy]

I paid $240 for two new unis and a center bearing installed on my VR. If you have no problem forking out the $1500 for someone to fix the diff, I'd spend the couple of hundred bucks or so getting the center bearing done.

 

[SavVYute]

If you have no problem forking out the $1500 for someone to fix the diff

LOL Thanks Chrispy. I do have a problem with forking out $1500 to fix the diff noise.
I've decided to go with it anyway.
With a bit of luck it might not be that much. Depends what they find wrong.
They can't give an exact quote until they pull it out and have a look.

They'll check the rest of the driveline too I hope.

 

[SavVYute]

Repairers phoned.
The diff has been checked over and bearings appear to be in reasonable condition.
However the gears are showing signs of pitting on the surfaces.

 

[gazatron]

hey i have a driveline noise aswell, i have a v8 vy 6 speed one tonner, and when i do hill starts sometimes it sounds like somone is booting the underside of the car sort of near the end of the gear box region the it stops and then sometimes when i go to change gear it clunks a bit when my foot lets off the accelarator. i have gone the centre bearing maybe a year a go, i have been told by 2 different mechanics that i have a split in my front drive line coupling, could that be it? also to me where the shaft comes out of the gearbox it feels sloppy to me, could it be a bearing or somehting in there? thanks

 

[SavVYute]

The front drive line joint in my auto is a rubber coupling called a 'Giubo Joint' named after the Italian guy who invented it.


If the manual VY has the same arrrangement I'd say that is where your problem could be.

They're fairly easy to replace but I've heard the joint itself is fairly expensive.



Another thing you can check is none of your gearbox mounts or the centre bearing mount are coming loose.