[alien]

So i've had this issue for ages now, and its finally annoying me enough to want to do something about it....

When i engine brake or reverse i get an off and on scraping sound from the drivers side rear. Its pretty loud too, enough that you can just hear it with all the windows up, over the sound of the gearbox and motor... Windows down and its insanely loud inside the cab, so i assume its pretty noticable to everyone else.

- The sound is in pulses, like a rotor is warped and its hitting metal on metal.
- It's related to the wheel speed and definitely sounds like its on the drivers side rear
- It isn't audible over 70km/hr (perhaps its pulsing too fast to hear at this speed?)
- I can't replicate it by tensioning the handbrake while driving or feathering the brakes, only on engine brake or reverse
- If i depress the clutch while engine braking the sound goes away, which leads me to believe its related to spring wrap/pinion angle
- It's been occurring since a week or so after the rear disc conversion (months ago) and hasn't gotten any worse

I made a vid today as well - jacked the rear end up, idling in 1st gear high range with the handbrake on a bit, and the sound was there:


(Note: when i have the wheel off, there's no nuts holding the rotor on so it was free to move).

Any ideas???

[atari4x4]

checked the uni's lately or are you sure it's the RH rear?

[alien]

I've given the driveshaft a shake around and its solid as, no slop....

In that vid the sound DEFINITELY comes from the drivers side rear caliper - the other side made no sound at all, and moving my ear around the area the sound was loudest at the bottom of the caliper.

[atari4x4]

ahhh cool, i had a squeeky UJ that would only make noise in reverse & when checking the tail shaft you couldn't feel it but once removed you could feel the notchiness.

[alien]

oh ok - yeah the squeak in the vid is my trac bar moving =) The rear uni is about 2 years old, the one before that lasted about 3 years before i shattered it bouncing around on some rocks.

i'm kinda glad the sound is from the caliper area - my fear was that it was something diff related and transferring the sound down the axle to the hub...

[sideways]

Didn't Suzistore fit it all? Take it back and get them to find out what it is and fix it, it's their problem.

[atari4x4]

[alien]

That's like arguing that Joeblow made the floater kit so he should fix it... lol

I can't get to suzistore during the week for them to look anyway.

I don't care about the cost, i just want to diagnose and fix it =)

[christover1]

Maybe anti squeal pads fallen out? Sticky caliper?

[christover1]

If anything is rubbing, it would leave an obvious shiny spot

[Daves4wd]

Might get flamed for this bit is it a bearing??? Maybe had a little shit in the grease??? Just a thought... But could be a little rock stuck in the pads???

[Daves4wd]

Have you try's it with out the dust off where the locking nut it is for the bearing??

[Teracis]

Bloody hell that camera moves around fast!

Looking at it from 1:00 (start a bit before and you pan around and look directly at the rotor edge on) it appears that the rotor is not centered on the axle, or slightly out of round. Watch closely, it could just be me, I know you said that it is free to move because of the lack of wheel nuts, maybe do the test again with them on?
Maybe the slight movement I think I'm seeing is causing it to scrape across the pad in a motion perpendicular to the normal direction of rubbing, i.e. vertical in this case rather than rotational and causing the noise?

Does it do it with the caliper undone or pads removed?

Also, which joeblow kit have you used with regards to calipers and was there any issues with installing that you didn't anticipate before starting?

[Red89]

Take the caliper off and do it again with a block of wood replacing the disk in the caliper, this should isolate whether it is brake or axle related.

[alien]

Thanks guys - i'll give them a crack next weekend. Teracis - i checked the rotor for movement up/down and side/side before taking the wheel off and it is true - the movement in the vid is cos there's no wheel nuts on there.

Daves4wd - it 100% sounds like its from the caliper and not from the hub, which is why i'm doubtful its a bearing (you can hear it in the vid as i move the camera to and from the caliper).

[shep]

Sounds like the pad wear indercator to me

[31zook]

What MC are you using? If its stock sierra it means that the MC will be holding redesidual pressure on the caliper. With it being bugger all pressure it might be just enough to find a small warp or edge on the disk.

Does it do it in reverse?

What calipers are you using? My galant don't do it.

[alien]

31zook - yep, sierra MC and it does it in reverse... pintara calipers and jimny rotors.

[alien]

So i'm pretty sure i know what the issue is...

Dirty / Pitted rotors. Makes sense given the noise started after my first trip out 4wding after the disc conversion.

I just dumped a whole can of wurth brake cleaner into the drivers side rotor/pads and took it for a spin and the noise is much quieter, enough so that i can hear the passenger side making a noise now.

So it looks like i basically just have to live with the sound, cos if i replace the rotors they're just going to go through the same thing on the next 4wd trip.