I just recently noticed that when I make left turns, I hear a knocking (not clicking) sound coming from the front end. I raised the front end and when I grabbed the front wheels at 12 and 6, I was able to rock them back and fourth with very little but noticeable play. I didn't find any other loose suspension components, but I may have over looked something. Any ideas? BTW I have a 76 Cutlass.

 

loose wheel bearings are my first thought.


bill

 

Yeah, or lug nuts.
My son called Tuesday evening, out in the blue car, hears knocking in the front wheel. All front lug nuts loose. I guess I failed to torque them sometime.

 

Wheel bearings.

 

I'm going with wheel bearings. Thanks for the input guys!

 

Agreed. Lug nuts or wheel bearings.

- Eric

 

I like to start with the easy things first. Checking lug nut torque takes seconds. If that's not it, adjust the wheel bearings.

 

I'd actually take them out, clean, inspect and repack or replace if necessary.

 

I had an issue once where I had a noise coming from the front of a 70 cutlass I had just purchased and it turned out that somewhere along the line the brakes were done and not tightened down properly and it caused the loose wheel to rock enough to make the race spin inside of the hub, splitting the race, and making it dig into the hub. I ended have to replace it (front drum car). Now I doubt that your issue is that bad, but it if were it would be a simple matter of just replacing the rotor and wheel bearings.
Even if its just the bearing that are bad I would just get new one (for both sides) as they are cheap enough and repack with grease and go. I think 4 bearings and 2 seals should be less than $30 for that car for the good ones and possibly less than $20 for the cheaper ones.

YMMV. my $.02.

 

I'd check the ball joints next.Be sure to jack it up under the A-frame keep the spring compressed.Don't jack it up in the middle.It helps to have a friend wigle the wheel while you look.
railguy

 

Ha. First reaction was to think about CV joints. That's what happens when you have a Toronado and Eldorado.

 

Okay, the front driver side is still knocking. It is only on left turns and when I hit a dip like turning left into my driveway. I have now checked the lug nuts, installed new bearings, UCA bushings, upper ball joints, sway bar end links and sway bar bushings. I had a friend push up and down on the front left side of the bumper which duplicated the sound. While he was doing this, I grabbed various suspension parts to feel for any looseness or vibration. The only thing I felt vibration through was the coil spring. The bushings at the top do not look perished. I hate to keep spending money only to still have this annoying problem. Help!

 

Check the shock absorber for loose or worn bushings or even broken. Speaking of broken, check the coil spring as well.

Hope this helps.

 

You didn't mention the lower ball joint.

Have you jacked the car up slightly by the frame, stuck a 6' pipe under the wheel, and pried up and down to wiggle the wheel up and down, while having a helper watch the lower ball joint?

Also, sometime the upper bushings can look okay unless you catch them at just the right angle - try jacking the car up with the wheel off the ground, putting a bottle jack under the lower control arm to get it up just about an inch or so, and having someone give the wheel a good strong side to side wiggle while you watch the bushings.

- Eric

 

Have you also checked your frame to body bushings? We did not suggest changing parts, we suggested to check the serviceability.

 

I checked the lower ball joints and everything looked good. nothing perished and no movement. I have not checked body to frame bushings. The upside to this is that everything will need to be replaced anyway.

 

Might as well check the motor mounts.Probable not it but pretty easy to do.
railguy

 

So it definitely sounds like a suspension issue. My first guess would be something going on with the coil spring. You should bee able to see the top & bottom of the spring to see if a coil broke off. I've seen that few times. Or as mentioned before maybe something going on with the shock absorber.

 

You can definitely have a break at the end if a coil spring that you essentially cannot see, so look carefully.

- Eric

 

Is recording it possible? Most digital cameras today have video record capacity. You can pick up a cheap dollar store micro tripod and duct tape it in a location to capture it .. particularly as you say there's one turn where it always happens. I've got one that's also a c clamp .. very useful. Alternately, just have someone hold the camera at the left turning dip.

 

My Guess would be the shock. Physically put a wrench on the top portion and make sure it is tight. I have seen a couple of times it looks fine, but enough play on the top bushing to make exactly the knocking sound you describe.

 

Okay, so I'm still figuring out this clunk sound. I bought a mechanic's stethoscope, and checked every area of the suspension. The sound is knocking loud and clear from the coil spring. I am going to pull it tomorrow to see if anything looks unusual. I'm sure I'll be chiming back in for advice until this is solved.

 

Very good chance of a broken spring, then.

I had a car with one front spring broken in four pieces, all at the very bottom - the ride height was almost even, and you absolutely couldn't see it with the spring installed.

- Eric

 

You could also check to see that the lower control arm bushings are torqued. When I was young we replaced front coil springs on my Chevelle and did not torque these bushings properly and it resulted in a loud knock. I know you probably know this but they must be torqued while the wheel is on the ground.

Cheers Mike
1969 442

 

You know to chain that spring before you remove the pressure ...

 

Well, I haven't got the spring out yet, but this is clearly a spiral spring break.

 

Looks like rcrac3r wins the prize!

- Eric

 

Big thanks to all that responded. You guys are awesome!