JC316

I have never seen anything like this, it's like I'm a weird problem magnet. I have an 85 corvette with the 4+3 manual transmission and it's making an heck of a racket. It's a loud click and rattle that happens when cold and increases with engine speed, but ONLY when the suspension is loaded.

Get out of the car and it stops, sit down and it starts clicking. Bounce on the suspension and it goes from quiet to clicking every time you land and compress the suspension. It also stops when the clutch is depressed. Obviously it's something in the transmission, but what? The bellhousing bolts are tight, as are the trans to bellhousing bolts, it's not the TOB, pilot bearing, or clutch fork.

The transmission and OD unit function as they should, just this weird noise, and it does go completely away once the car warms up. Any ideas?

antfarmer2

something loose in the exaust? just going another way.

JC316

Great minds think alike, it was the first place I looked. Nothing, no leaks or broken cats, or anything in the exhaust that would make this noise.

antfarmer2

no loose exaust maifold or cracks hidden under heat shields? I would get a piece of hose and poke around listen careful should be able to narrow it down.

VikingTrad3r

mine was flywheel.

JC316

Nope, nothing there. This is definitely a mechanical clacking, I need to get a video of it happening. The closest thing that I have heard to this was a 98 Mustang GT that I had, the TOB sleeve broke off, which allowed the clutch fork to flop around.

Cracked or loose?

BOOT77

Broken engine mount?

edit: I'd also look at the pulleys mostly the tensioner. Also I am assuming your not talking bout valvetrain IE rockers

VikingTrad3r

cracked. i noticed at first it would groan going over bumps with largecompression.

then it started to make a click click noise corresponding to rpm.

VikingTrad3r

good idea.

antfarmer2

maybe a loose flywheel wieght or evan a bad serp belt bouncing things around. where is the sound comming from?

VikingTrad3r

I should qualify that mine was with an automatic transmission I never remember which one is the flexplate vs flywheel but same thing.

JC316

Sounds is coming from behind the drivers wheel well, which would be in the flywheel area. It's a new flywheel on there, but anything is possible. I can look at the motor mounts as well. It's not in the serpentine system, I already tried it with the belt off and it's still making the noise. Definitely not in the engine, not the valvetrain or lower end.

VikingTrad3r

jack, support with plenty of redundancy, remove the inspection plate (do manuals have these?) and check for loose bolts. ive head they can back out and might be striking something.

you r getting close.

SJW

Also examine the bellhousing and transmission mounting ears for cracks and/or loose bolts.

Live well,

SJW

antfarmer2

TorchTarga94

Make sure C-Beam bolts are torqued correctly and verify there are no cracks at either the trans tail shaft housing or the diff housing where the C-Beam bolts pass through.

HlhnEast

Definitely check the fly wheel bolts and weights and see if there is any looseness.