Help me identify this noise

[Brendan-s]

Just recently the Zook starting make a horrible metal-on-metal grinding noise. It occurs once the car gets some speed up, sometimes around 40km/h, sometimes around 60km/h. The only way to get it to stop is to slow below 20km/h. It's not relative to engine RPM or what gear I'm in as the noise is there even in neutral and when the motor is being revved (although i still have to be doing at least 40km/h for it to occur). It's constant, as in once it starts it doesn't get any worse until you come to a stop when it disappears.

It *seems* to be coming from the back half of the car. Although I can't confirm that as I can only hear it when I'm driving.

I'm thinking either rear diff, rear wheel bearings or perhaps transfer case. Area around transfer I noticed is wet with a bit of oil when I had a look under yesterday. Going to jack the rear up and check for play in the bearings at lunch time, and this weekend I'm going to drain the t-case and rear diff oils and replace (although they seemed fine with no metal particles or anything when I did em 5000km ago).

Any ideas of what else to look for?

[Brendan-s]

Just had a look and no play in the rear wheel bearings. However, in the daylight the oil from the transfer is much worse than I thought. My guess is this is the problem. Do the symptoms point to this?

[BundyRumandCoke]

Is the oil coming from a tailshaft yoke? And is there any movement there? If so, then an output bearing may be gone, which has flogged the oil seal, allowing the leak to occur.

[lay80n]

Bearing, or dry/failing uni. My uni's make that noise when they are going.

Layto....

[Brendan-s]

Will have a better look at lunch where exactly the oil is coming from.

I tell you I will be red-faced if I just need to pump some more grease into the unis! I have been slack on maintenance lately, haven't been driving it much so haven't been maintaining it.

[spamwell]

my brake drum backing plates where slightly bent and i got that noise.

and also got that noise when wheel bearings where on there way out if it is not the uni's pull of the drums see if they have been rubbing.

sam

[Brendan-s]

Thanks Sam. when I get home tonight I'll get some more grease into the unis. If not this weekend I'll have a look at the drums.

Does the fact there's no play in the wheel bearings at all mean they're in good nick, or could they still need replacing?

[spamwell]

i found it hard to figure out when mine where gone untill they made heaps of noise lol. but if there is no movement they should be ok

[Brendan-s]

Had to go up the post office at lunch (fuel pump finally came, no more pissing out oil!!!) and noticed it would grind at any speed turning left (well anything above walking pace), but wouldn't really grind turning right. I checked the front bearings, and the front right has about 3mm play in it. Plus it clicks when you spin the wheel. Gonna replace it this weekend and see how it goes.

[Turbz]

Don't you just love cars

It is a good feeling but when you get it all right. Good luck son !

[Brendan-s]

Heh. Yeah... bloody money pits, but that's what you get for buying a 20 year old car.

On a side note I am going on the weekend to look at a 240GL Volvo station wagon... haha. I want something the missus and I can take away on a roadtrip in over summer, and sleep in the back of. Plus be a little more of a highway cruiser than the Zook

I never learn

[Brendan-s]

Well it's not the uni, I pumped it full o' grease last night and it's still making the noise.

Putting a new clutch in next week (will it ever end), and in preparation I'm going to degrease the buggery out of the underbody. So hopefully I'll be able to see what's leaking and maybe get a further clue.

[MKPatrolGuy]

Had to go up the post office at lunch (fuel pump finally came, no more pissing out oil!!!) and noticed it would grind at any speed turning left (well anything above walking pace), but wouldn't really grind turning right. I checked the front bearings, and the front right has about 3mm play in it. Plus it clicks when you spin the wheel. Gonna replace it this weekend and see how it goes.

I'd be replacing your front wheel bearings if they are clicking when spun, or at least pull them out and regrease them. Otherwise they may collapse and lock up the when (I know from experience )

Dave

[spamwell]

pull your drum off lol exacly the same symptoms as my bent backing plate. did not make a noise in a straight line, then made heaps round corners

[cloughy]

No wonder the tech. shines in 4WDmonthly

[chimpboy]

No wonder the tech. shines in 4WDmonthly

I can't believe it took you so long!

[Ruffy]

No wonder the tech. shines in 4WDmonthly

I can't believe it took you so long!

[cloughy]

No wonder the tech. shines in 4WDmonthly

I can't believe it took you so long!

[jungle_surfer]

No wonder the tech. shines in 4WDmonthly

I can't believe it took you so long!

I was having a good read about diagnosing strange noises and wheel bearing problems, and then this... What are you guys talking about???

[HeathGQ]

4130warrior is Brendan from 4wd Action.....

[jungle_surfer]

Ahhhhhhh..... *nods head*

Back to tech discussion, I might have buggered my front wheel bearings too, so I'll try them for play (jack up, put on stands, grab top and bottom and wobble - how much is too much?) and clicks.