Rhythmic clunking

The Dark Side of Will · Fri Nov 03, 2006 9:48 pm

The rear of the Formula just started making a repeating muffled clunking noise that is dependent on vehicle speed. It makes the noise under mild acceleration and all engine braking conditions, but the noise disappears with even mild brake application. I'm going to guess that it's a wheel bearing until I have a chance to investigate further (tomorrow evening). Anyone else care to take a stab at it?

The real problem is that my girl likes to do it in time with the clunking, but I have to go like 100 mph in order to be fast enough for her.

Shaun41178(2) · Post by **Shaun41178(2)** » Fri Nov 03, 2006 10:03 pm

I dont' think Bearings clunk. I think its soemthing else.

Fast88Fiero · Post by **Fast88Fiero** » Fri Nov 03, 2006 10:07 pm

I had a rear caliper bolt come loose on my 88 coupe and I had a similar noise. Maybe thats it?

Series8217 · Post by **Series8217** » Fri Nov 03, 2006 10:30 pm

Caliper bolt loose.

Otherwise you have a warped rotor and/or worn slider pins so the brake pad is sliding back when it catches on the rotor every rotation and making a banging sound.

p8ntman442 · Post by **p8ntman442** » Sat Nov 04, 2006 8:29 am

Broken tranny mount, your cv shaft is rubbing your cradle. /guess

The Dark Side of Will · Sat Nov 04, 2006 1:50 pm

Series8217 wrote:Caliper bolt loose.

Otherwise you have a warped rotor and/or worn slider pins so the brake pad is sliding back when it catches on the rotor every rotation and making a banging sound.

Interesting. How prone are the '88's to this happening? I didn't torque the bolts, but I tightened them pretty well when I put the brakes back together after the clutch job. I can check that before I move the car anywhere else, too.

Do you use new locktite when you work on your calipers? I find myself using anti-seize on things on which GM used loctite.

Series8217 · Post by **Series8217** » Sat Nov 04, 2006 3:15 pm

The Dark Side of Will wrote:
Series8217 wrote:Caliper bolt loose.

Otherwise you have a warped rotor and/or worn slider pins so the brake pad is sliding back when it catches on the rotor every rotation and making a banging sound.
Interesting. How prone are the '88's to this happening? I didn't torque the bolts, but I tightened them pretty well when I put the brakes back together after the clutch job. I can check that before I move the car anywhere else, too.

Happens all the time.

Do you use new locktite when you work on your calipers? I find myself using anti-seize on things on which GM used loctite.

Anti-seize? Eek. I use loctite. You definitely don't want to use anti-sieze on those bolts. There is very little thread engagement. Use blue loctite. You'll have to get all that antisieze off.. liberal application of brake cleaner should work.
If you're worried about thread corrosion preventing future disassembly.. loctite prevent's corrosion too.

Fast88Fiero · Post by **Fast88Fiero** » Sun Nov 05, 2006 12:54 am

Series8217 wrote: Anti-seize? Eek. I use loctite. You definitely don't want to use anti-sieze on those bolts. There is very little thread engagement. Use blue loctite. You'll have to get all that antisieze off.. liberal application of brake cleaner should work.
If you're worried about thread corrosion preventing future disassembly.. loctite prevent's corrosion too.

:withstupid: Happens all the time! I use blue loctite when I put my brakes back together. It sucks when the caliper comes off, trust me. :puke:

The Dark Side of Will · Sun Nov 05, 2006 8:46 am

Found the problem. My dumb ass hadn't fully torqued the lug studs the last time I had the wheels off. It finally caught up with me. I had to replace two nuts and one stud, but it could have been a lot worse.

The Dark Side of Will · Mon Nov 06, 2006 10:42 am

Series8217 wrote:
Do you use new locktite when you work on your calipers? I find myself using anti-seize on things on which GM used loctite.
Anti-seize? Eek. I use loctite. You definitely don't want to use anti-sieze on those bolts. There is very little thread engagement. Use blue loctite. You'll have to get all that antisieze off.. liberal application of brake cleaner should work.
If you're worried about thread corrosion preventing future disassembly.. loctite prevent's corrosion too.

Do you tighten by hand or torque the bolts? The spec is 28 ftlbs and that's not much at all for a 12mm bolt, considering that lug studs go to 100 ftlbs.

Mach10 · Post by **Mach10** » Mon Nov 13, 2006 4:42 pm

I know you found the problem...

But I had the same thing happen to me.
Drove it like that for 2 weeks before I realized that the problem was the passenger-side seatbelt was hanging outside the car and whanging on the body panels...

Point being: Everyone is allowed a quota of stupidity. How much depends on what your yearly salary is. I.E., the more you make, the less you are permitted to fuck up.

I don't make SFA, so I'm allowed to be as stoopid as I like.