www.RX7fb.com

Hi everyone,

I have a noise that I can't really identify what it actually could be, I hope one of you had a similar problem previously.

The car is 1982 S2 Euro spec completely stock with rear discs and open diff.
After 5-10 minutes of driving I get a really nasty noise. Sometimes it sounds like a grinding noise (almost as if the tyre is rubbing on the fender), another time it sounds like metal rubbing on metal. I guess it comes from the rear but I could swear it comes from the front sometimes too.
It occurs at any speed and only under light breaking or driving through a corner without any throttle input. I couldn't replicate the noise on the lift (warm and cold).

Here are the things that I already checked:
-The tyres aren't rubbing anywhere
-I don't have any play in the bushings, although they are starting to go brittle
-The wheel bearings run nicely and don't have any play
-The brake callipers aren't stuck, as well as the brake pads
-The rear discs had quite a bit of rust on the outer and inner edge, which I removed
-I changed the brake fluid, as well as the rear diff oil (which didn't have any metal flakes or pieces in it
-The exhaust isn't rubbing or touching anywhere hot or cold
-The diff sounds fine while turning by hand

The only thing I that could imagine, are rear axles rubbing somewhere, but I have no experience with a solid axle at all, so I don't know if this is even possible.

Cheers.
Ben.

Jack up the rear end so that weight is resting on the rear axle.You need to get both wheels off the ground. Rotate the rear wheels and check that the exhaust sheilding is not fouling the driveshaft as it turns.

Thanks, I will try that out.

It's the only way to simulate rear suspension load unless you have a four post lift.

Did you check the handbrake cables? There is a spring holding them away from the rim. I had the right side cable just touching the wheel.

Benjonara wrote: ↑Sat Apr 25, 2020 5:52 pm It occurs at any speed and only under light breaking or driving through a corner without any throttle input. I couldn't replicate the noise on the lift (warm and cold).

I had a similar issue years back from a 3 series, if it occurs at low speed as mine done I had a friend run alongside the car at low speed and pinpoint the exact location of the noise.

If your guessing between front back, tyre rubbing, suspension noises, diff noises you'll end up playing car part bingo in hope that it fixes the issue.

If you can isolate the location of the noise you'll figure it out from there.


Rich

I could now identify the noise coming definitely from the rear, with someone sitting in the rear seats (poor bloke) and when slightly pulling the handbrake it immediately disappears. So I guess it comes from the rear brakes.
I ordered rear brake pads, since they aren't that expensive and I'll try to get the springs for the pads to hold them a litt bit better. Hopefully I won't have to change the rear discs (btw. does anybody know where to get them except EBC?).

Cheers,
Ben.

How many notches does your handbrake come up when applied? There is an adjuster by the handle to take up any slack in the cables. Try that first.

Sounds a little bit like the issue I had:

viewtopic.php?f=4&t=4355&start=22

Maybe a sticking or seized brake piston?

Benjonara wrote: ↑Tue Apr 28, 2020 8:42 pm ....when slightly pulling the handbrake it immediately disappears.

Based on my experience, it might well be rust on the rotors rubbing against the pads. I had the exact same issue (albeit on a a Civic) where pulling the handbrake up slightly would mute the rhythmic rubbing sound. Solution was to replace the rotors and pads