Rear "clicking" sound

[Thomas H.]

Thinking cap time.....

Lately when I am driving the car, I hear a "click" type sound coming from the right rear. The sound occurs when starting out, sort of several clicks in a row then dissappears once I get going. I can somtimes hear it when letting off the gas and coming to a stop. At first I was thinking posi clutches, but it does not do it when doing figure 8's in a parking lot.

Now I'm thinking u-joint, but they are all new (within a year, maybe 250 miles), The ones on the driveshaft have no grease fittings while the ones I used on the half shafts do. All of the bolts are tight. I had it up on a lift and could not see any play in any of the shafts / joints.

The trailing arms were redone by Bairs 2 years ago. I rebuilt the diff around the same time and have two bottles of the GM posi additive in it.

I have pulled the center cap and trim ring and still have the noise. It sounds like it is coming from the hub area. I can not recreate it with the car on jacks.

I was toying with swapping the half shafts from side to side to see if the noise follows.

Pertinent info.... 71 LS5, 4 speed, I have rebuilt all of the mechanicals (everything stock specs) within the last two years and other then this annoying click, the car runs and handles great

Ideas?

Thanks,

Tom

[Chuck R.]

Re: Rear "clicking" sound

Hi Tom,

I would think if it were u-joints, they would be constantly clicking or worse.

I'd be suspect of the emergency brake.

One possible culprit may be that one of the emergency brake retaining springs has popped off and is dragging on the spindle as it rotates.

Chuck

[Duke W.]

Re: Rear "clicking" sound

It could be just about anything in the drivetrain.

What you need to do is get the car up in the air and do a thorough inspection. "Clicking" can be a sign of imminent wheel bearing failure, so rotate the rear wheels to check for smoothness and do a wiggle test to determine if the clearance is opening up.

Grab all the shafts from various angles and shaft clock positions and shake them looking for any movement at the joints, and push the wheels in and out to check differential side yoke endplay. Do a visual check of bushings (including all the diff. mount cushions) and use a pry bar to check for excess movement.

Also check all bolts/nuts for proper torque.

Duke

[Clem Z.]

Re: Rear "clicking" sound

Thinking cap time.....

Lately when I am driving the car, I hear a "click" type sound coming from the right rear. The sound occurs when starting out, sort of several clicks in a row then dissappears once I get going. I can somtimes hear it when letting off the gas and coming to a stop. At first I was thinking posi clutches, but it does not do it when doing figure 8's in a parking lot.

Now I'm thinking u-joint, but they are all new (within a year, maybe 250 miles), The ones on the driveshaft have no grease fittings while the ones I used on the half shafts do. All of the bolts are tight. I had it up on a lift and could not see any play in any of the shafts / joints.

The trailing arms were redone by Bairs 2 years ago. I rebuilt the diff around the same time and have two bottles of the GM posi additive in it.

I have pulled the center cap and trim ring and still have the noise. It sounds like it is coming from the hub area. I can not recreate it with the car on jacks.

I was toying with swapping the half shafts from side to side to see if the noise follows.

Pertinent info.... 71 LS5, 4 speed, I have rebuilt all of the mechanicals (everything stock specs) within the last two years and other then this annoying click, the car runs and handles great

Ideas?

Thanks,

Tom

a poster on "vettheads" had the same problem with yogi's rebuilds. i never saw a post about what he found out.

[Don G.]

Re: Rear "clicking" sound

As others have stated, there are many possible causes of this problem. I will share my experience for what it is worth. I had a clicking sound in the rear left wheel I could hear at low speeds on a low mileage '75. At 5 mph on a subdivision street with no traffic, I slowly applied the emergency brake and then released it. At least for now, the noise has gone. You might also try just applying a notch or two on the e brake to see if it has any effect. If this helps, then it may warrant an internal inspection of the e brake to dtermine the root cause.

[Stuart F.]

Re: Rear "clicking" sound

This is probably way off base to your particular problem, but it shows how such strange clicking noises can be a cause for consternation; I had a clicking in my 63 when backing up slowly out of a drive way. I feared the worst and checked out everything external that I could see without locating the problem. It never got worse so I lived with it until the day came that I pulled my drums to replace my brakes. I had the J65 metallic brakes that are metallic pads induction welded on the shoes. Well, several of the pads had broken loose and were floating in the drums. After replacing the shoes with new Matrix Ceramic units that "Clicking" went away.

Stu Fox

[Joe L.]

Re: Rear "clicking" sound

Thinking cap time.....

Lately when I am driving the car, I hear a "click" type sound coming from the right rear. The sound occurs when starting out, sort of several clicks in a row then dissappears once I get going. I can somtimes hear it when letting off the gas and coming to a stop. At first I was thinking posi clutches, but it does not do it when doing figure 8's in a parking lot.

Now I'm thinking u-joint, but they are all new (within a year, maybe 250 miles), The ones on the driveshaft have no grease fittings while the ones I used on the half shafts do. All of the bolts are tight. I had it up on a lift and could not see any play in any of the shafts / joints.

The trailing arms were redone by Bairs 2 years ago. I rebuilt the diff around the same time and have two bottles of the GM posi additive in it.

I have pulled the center cap and trim ring and still have the noise. It sounds like it is coming from the hub area. I can not recreate it with the car on jacks.

I was toying with swapping the half shafts from side to side to see if the noise follows.

Pertinent info.... 71 LS5, 4 speed, I have rebuilt all of the mechanicals (everything stock specs) within the last two years and other then this annoying click, the car runs and handles great

Ideas?

Thanks,

Tom

Tom-----


Try removing the trim rings and see if the clicking goes away. It's a long-shot, but it's easy to do.

[Patrick H.]

Re: Rear "clicking" sound

Tom-----


Try removing the trim rings and see if the clicking goes away. It's a long-shot, but it's easy to do.

I had the same thought.
The silly trim pieces on my 70 Cutlass click all the time, and my right rear trim ring on the 71 Corvette also clicks. It has a broken clip, so that explains it.

Like Clem notes, we have a friend who's had the same problem. It improved over the miles but was still there when he sold the car.

Patrick

[Jim T.]

Re: Rear "clicking" sound

Since you have had your trailing arms rebuilt by Bair's I do not think you would have this problem with the rotors rivetted to the spindles and trued by Bair's before assembly.
In 1973 I took my original owner 70 to the largest/newest Chevrolet dealership in Dallas,TX with a noise problem. The work performed under warranty (1970 was the last year for 5 years 50,000 miles then) was replacement of the wheel bearings on the passenger side. Noise was gone when I got my 70 back. Replacement was done in the summer and driving usually was with A/C on. One day, a cooler morning I was driving with the windows down and at a slow speed I could hear a clicking. It would go away at a faster speed. I tlhough it was trim ring noise. Later I took my 70 about a year later back to the same dealership with a noise in the drivers rear. The wheel bearings were replaced under warranty. To make this story shorter, the problem was excessive runout of the rotor disc and it was pushing the
brake pads around. I verified this with removing both rear tires and supporting the trailing arms in a driving position and could see the excessive runout of the rotor discs moving the brake pads.
The rivets retaining the rotor discs to the spindles were missing and I no longer had the factory trued assembly.

[Harmon C.]

Re: Rear "clicking" sound

Tom said he pulled the trim ring and cap in his original post. I have had the original spring over the E-brake adjuster break.This has happened on two different cars and the sound is more like grinding to me but it could be called ticking.

[Thomas H.]

Re: Rear "clicking" sound

Thanks for all of the suggestions. I had expected to spend some time on the car today, but just didn't get to it. Tomorrow I'm going to the Rolex Sports Car race at the new track in NJ, so there will be nothing done on the car tomorrow either. Monday is a day off, so I intend to spend some time digging into the infamous click.

A few comments from the posts..... The click happens when starting out from a stop. Once I get going it goes away, except I am sometimes able to hear it when letting off the gas. Turning either right or left has no effect, nor does playing with the E-brake. It almost sounds like something is binding and releasing. I can not duplicate it with the car on jack stands, it needs to be under load.

Joe, At first I thought trim rings also, easy fix right? Nah, took rings and caps off and the noise is still there.

The rear rotors are riveted on so I really don't want to have to pull a rotor.

I think the first course of action is to remove the u-joints from the half shaft and inspect them. Then if the noise is still there I may swap them side to side. If it is still there, then I can be assured it is in the trailing arm somewhere.

I'll let everbody know what I find............... or don't find.

Thanks,
Tom

[Duke W.]

Re: Rear "clicking" sound

I think the first course of action is to remove the u-joints from the half shaft and inspect them. Then if the noise is still there I may swap them side to side. If it is still there, then I can be assured it is in the trailing arm somewhere.

Thanks,
Tom

WHAT!!!???...

Since the noise appears to be "torque sensitive" the first thing I would check is the front differential mount system - cushion condition and all bolt torques.''

Use a pry bar to see if the diff. has excess movement due to deteriorated cushions or loose bolts. The differential's torque reaction is transmitted to the frame by the front mount system, which can be several hundred pounds of force at the front mount in the lower gears.

Duke

[Daniel G.]

Re: Rear "clicking" sound

I just went through a clicking problem on my 63, it ended up being a rear wheel bearing, the clicking had no rythm, it came and went away

[Thomas H.]

Re: Rear "clicking" sound

Duke,

Thanks for the input. Every bushing is new. I did a complete rear suspension rebuild (using "stock" replacement parts, no fancy urethane bushings) two summers ago. Had the car over at a friends shop in June and we went over the front differential bushing and bolts (as you suggest). All are in good shape and properly torqued.

Tomorrow I plan on tearing into it. Hopefully I'll have some answers tomorrow evening........

Thanks,

Tom

[Joe C.]

Re: Rear "clicking" sound

Thanks for all of the suggestions. I had expected to spend some time on the car today, but just didn't get to it. Tomorrow I'm going to the Rolex Sports Car race at the new track in NJ, so there will be nothing done on the car tomorrow either. Monday is a day off, so I intend to spend some time digging into the infamous click.

A few comments from the posts..... The click happens when starting out from a stop. Once I get going it goes away, except I am sometimes able to hear it when letting off the gas. Turning either right or left has no effect, nor does playing with the E-brake. It almost sounds like something is binding and releasing. I can not duplicate it with the car on jack stands, it needs to be under load.

Joe, At first I thought trim rings also, easy fix right? Nah, took rings and caps off and the noise is still there.

The rear rotors are riveted on so I really don't want to have to pull a rotor.

I think the first course of action is to remove the u-joints from the half shaft and inspect them. Then if the noise is still there I may swap them side to side. If it is still there, then I can be assured it is in the trailing arm somewhere.

I'll let everbody know what I find............... or don't find.

Thanks,
Tom

I can not duplicate it with the car on jack stands, it needs to be under load.

I believe that I see the culprit in the above sentence.

The usual suspects are u-joints, trim rings, wheel bearings, brake/ebrake hardware, rotor runout.

In your first post, you eliminated the trim rings.

If the u-joints were quiet while on the lift, AT FULL EXTENSION, then that would eliminate them. That is, provided you were driving the rear wheels while they were off the ground.

Excessive rotor runout will cause pulsation in your brake pedal, and in severe cases, will pump air into the calipers, causing a spongy pedal. Since you don't complain about either of those, then chances are very slim that runout is your problem, although it is still possible.

But, if it only happens with a RADIAL LOAD applied, then it points toward the wheel bearings.

As far as not being apparent when traveling faster................well, it's still there, but the frequency is so high, that it gets "lost" in the ambient noise.

Joe