THSCC Forums

i got the e30 into a position to do a test drive yesterday...as expected, i heard a lot of new noises and vibrations and of course that makes me nervous. i can account for most of it except a "whirring" coming from the rear. at low speeds you can notice it change pitch with the rotation of the wheels. it sounds mostly like pads rubbing. my first thought is that it's the parking brake shoes rubbing, but there's no real way to tell without pulling off the hub again and i really don't want to do that. any ideas?

little background - no interior, no sound deadening, replaced everything bushing front and rear, new control arms, new rear trailing arm bushings, etc., 4.10 diff, brakes, ss lines, rear shock mounts, etc.

also, i know that if you lift the rear end and turn one wheel, then the other turns as well...is there supposed to be a little "play" in that or should both wheels turn in perfect sync. with mine, i have to turn one wheel a couple of degrees before the other will move.

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05 MCS

On my old Mustang, there is some rotational slack when turning the rear wheels by hand. And as you well know, there's some healthy side-to-side play in the axles too

Were the interior & insulation removed before you did the mechanical work?

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Art McDonald
Premier Amateur #518
2008 Dishman Cup
Pivot Cone Snob

Rodney is a waxer (but in a good way)

My FF has play with the Hewland transaxle. No limited slip so the opposite wheel turns the other way, of course. All my mustangs and any other car I've had have play.

Is the 4.10 diff new? If so, the noise could easily be gear whine. Does it change between accel, coast, and decel at the same speed? If so, gear whine is likely. Remember with no sound insul you will hear a LOT of noises you couldn't hear before.

If you can get to the pads try prying them back a little to eliminate any drag and see if the noise goes away with the car on a jack.

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Dick Rasmussen

FS 50 2018 Mustang GT

nope...both were done at the same time.

it's not an issue of "this has always been there and i just never heard it before."

i took the car out to a very slight slope. put it in neutral and let it roll. as soon as the car gets to a walking pace, you can hear it clear as day.

the pitch changes with the tire rotation like i said...that's why i think it's the pads.

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05 MCS

One way to check it is pads or parking brake shoes is to jack the rear of car up and run the car in gear on jack stands at idle speed in different gears to get different wheel speeds. Chock the front wheels if they are still on the ground. You might see how long it takes for the wheels to stop when you take it out of gear. Try applying very light amount of parking brake to see if there is any change. Are you sure the main pads aren't dragging? For them you can try prying the pads away from the rotors a little and rerunning the in gear tests. Also if pads or parking brake shoes are dragging you can try this test for awhile without any braking and then feel the drums, calipers, back of shoes, and maybe even rotors to see if they are warm or even hot (rotors). If you started with cold rotors there really shouldn't be any significant heat unless there is drag.

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Dick Rasmussen

FS 50 2018 Mustang GT

I have had a pulsing scraping noise at low speed that went away when I replaced the right parking brake shoe. The noise recently came back.

Like Dick suggested I removed the rear wheels and spread the brake pads apart so they were not scraping. I can turn the rotor by hand and hear the scraping sound.

When I get a chance I am going to pull the rotor and see if I can free up the parking brake assembly.

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Mitch Moore