Thursday, May 7, 2009

A New Noise, Cheap Shock Extenders.

Well I got the lag out of the Nova, and boom a noise popped up. An odd noise, not a good noise. This was the noise I knew was going to be evil, or something stupid.

1976 Chevy Nova, 327

I heard a bad grinding noise, mixed with what sounded like my exhaust being ripped off. The first day this year I had her out I heard it a little, then it went away. Then it came back. Then it went away. Second day it came back with a vengeance, sounded like someone was kicking the crap out of the back of my car.

At first I thought it was "winter brake dust" working itself out. But not after the second day.

First thought was oh no, the rear end is clunking. I stomped the peddle either to see if the posi was working with no lag, or snap the axle and finish it off. No lag, no pull. Ok the back axle was fine. I didn't break it.

Maybe the exhaust was dragging? But no, the sound was hit and miss, not constant. What else, wheel bearing? Those usually scream. Brakes? Rear wheel cylinders usually leak, not freeze and grind when they go out.

Chevy brake shoes

So I drove home clunking and grinding all the way. When I got home I decided to jack the rear end up and take a peek. I jacked both sides up and listened as I turned the wheels.

Nothing. Not a sound. No axle play, the brakes didn't stick, no noise. So it had to be something while weight was on the car or the tire was spinning faster than my hand could move it.

So I pulled off the passenger brake drum, perfect.

So I pulled off the driver brake drum, perfect . . . wait a minute.

Chev shock extender, grinding

My driver side shock was a bit too short when I installed my 5" drag shackles so I had to put an extender on the base of the shock.

So the base of my shock was held up, and the extender mount now had flipped out, holding the shock against the lip of my brake drum. I noticed this when I looked at my shock.

There was a lovely polished, ground down, spot on the shock, and when I looked at my drum there was a polished edge to it.

1976 Nova, Chev Brake Drum

So the grinding must of been the mount and shock rubbing on the drum, when it caught a divot, it banged. Sometimes it banged hard enough the kick the shock back up, and in place. Then no noise until I cornered or hit a bump that gave it enough play room to let the drum and shock start to make out.

1976 Nova, Chevy Brake Drum, Shock Extender, too close

Chevy Shock, Rub, bad extender

So I took the extension mount off.

Unfortunately the shock wouldn't reach(knew this), however I jacked up the rear suspension, and got enough slack to bolt the shock on. I lost no ride height but I know the suspension is pulling on the shock, hard.

I am not too worried about the shocks. My rear end has heavy duty leafs, 5" drag shackles, and 2500lb overloads. The shocks are just for show, the never get to bounce more than a 1/8" on a rough road. That and the shocks are about 8 years old. If I put new ones on they "freeze" and go bad in months, this happens because they don't get to move, they are pretty much held stationary 90% of the time. Car doesn't drive in winter, and when it does drive it takes a good bump then the socks only get about a 1/8-1/4" of bounce. I know because I've stood in my trunk and jumped up and down.

But the noise should be fixed now, I just have to decide whether to cut the shock extension mount down, or just not use it. I hate to have it rub again, but I don't want the shock being ripped apart and coming off while driving. I worry about it hitting my gas tank and putting a hole in it.

But alas, it was stupid problem noise not a evil noise. So the moral is always look for stupid problems, and don't buy cheap shock extenders.

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