Clicking Noise

**Wesman** · 10-12-2010, 03:34 PM

Just finished rebuilding the rear in my T/A. The Auburn broke so I replaced it with a Detroit TrueTrac and a set of used 3.42 gears.

The problem is when the car is driven, at any speed above about 10MPH, there is an audible "clicking" sound that comes from the rear axle area. It is in time with the wheels, meaning for each wheel revolution one "click" can be heard. I pulled the rear back apart, double checked everything, and it all seems fine. The gears were bought used, so there are a couple of marks on the outside edge of the ring gear, but nothing major, and no marks on the contact area.

For the techs, the rear is set to .006 backlash and 25 in/lbs preload on the pinion bearings. All bearings are new Timken bearings. I used a solid pinion spacer with shims to set pinion preload. Gear mesh pattern was good.

After having this thing apart twice, I'm really stumped here. Any ideas would be helpful.

**Smittro** · 10-12-2010, 03:46 PM

Imho if everything internally specs out like you said I'd start looking @ the brakes or elsewhere.. just my .02 Prolly something simple..

**Wesman** · 10-12-2010, 04:53 PM

Originally Posted by Smittro

Imho if everything internally specs out like you said I'd start looking @ the brakes or elsewhere.. just my .02 Prolly something simple..

Yea thats my thought as well. I've double and triple checked almost everything. It also doesn't seem to do it in reverse.

Only thing I can think of is its the used gears I got. Which really, really pisses me off.

**Cutlass** · 10-12-2010, 06:01 PM

Is it like this noise Ed had?
Pulsating Noise

**Wesman** · 10-12-2010, 06:06 PM

Originally Posted by Cutlass

Is it like this noise Ed had?
Pulsating Noise

Not quite...but similar. In the video, the noise has a sort of whine to it. Mine is a distinct click/clatter sound with each revolution of the wheels. Like a stick in a bicycle wheel.

ABS sensor is definitely a possibility though, thanks for the suggestion. I'll have to check that out.

**Cutlass** · 10-12-2010, 06:48 PM

Originally Posted by Wesman

Mine is a distinct click/clatter sound with each revolution of the wheels. Like a stick in a bicycle wheel.

That description really sounds like a brake backing plate that is a little tweaked and rubbing somewhere.

**Wesman** · 10-12-2010, 07:03 PM

Originally Posted by Cutlass

That description really sounds like a brake backing plate that is a little tweaked and rubbing somewhere.

I agree...but I don't have any backing plates

However, my rear rotors are pretty beat and have a nasty lip on them on the rotor face as well as in the drum hat. Perhaps they are touching somewhere and rubbing, creating the noise. I'll check that as well.

**Smittro** · 10-12-2010, 09:29 PM

I had the parking brakeshoe come off the ring before and was laying in the hat.. Maybe you lost one when you put the rotors back on..

**Cutlass** · 10-13-2010, 05:07 AM

Except he said he doesn't have backing plates so he must not have a parking brake?

**Smittro** · 10-13-2010, 05:19 AM

Originally Posted by Cutlass

Except he said he doesn't have backing plates so he must not have a parking brake?

Good (?) But he mentioned the drum hat having wear so I assumed he had a p-brake... I'm not sure the backing plate is actually needed for the p-brake to funtion..

**Cutlass** · 10-13-2010, 05:28 AM

Yeah I haven't look at one in a quite a while, but I was thinking the PB shoes and cable attaches to backing plate...I'm not sure though.

**Smittro** · 10-13-2010, 10:17 AM

Originally Posted by Cutlass

Yeah I haven't look at one in a quite a while, but I was thinking the PB shoes and cable attaches to backing plate...I'm not sure though.

I'd have to look too. I have'nt changed brakes/rotors in 2+ years..

**DIRTY JERZY** · 10-13-2010, 10:20 AM

u-joint?

**35th-ANV-SS** · 10-13-2010, 12:29 PM

Before reading that was my first two thoughts...brakes or u-joint related.

Does it sound like metal on metal or no? Could be the brake caliper hanging up or the brake clip rubbing on the housing.

**Wesman** · 10-13-2010, 08:07 PM

Originally Posted by Cutlass

Except he said he doesn't have backing plates so he must not have a parking brake?

Thats my error, sorry should have clarified.

I have stock backing plates for the parking brake setup, but no backing plate for the rotors, as are all the 98-02 F-bodies. So basically I just meant that there were no backing plates behind the rotors to rub against them, just backing plates for the e-brake.

My mistake

Haven't had a chance to mess with it since I drove it the other nite, been busy fixing other people's cars!! Guess I'll have to put it on the lift again and see if I can pinpoint the noise.

**Wesman** · 10-24-2010, 04:48 PM

Update:

Ran the car on jackstands again. Sounds like a almost like a loose pinion bearing, and its more of a repeated clunking noise than a click.

I also took a video, heres the noise:

You can start to hear the noise about 10 seconds into the video, its loudest when I put the camera under the differential.

**bberretta** · 10-24-2010, 05:24 PM

Sounds almost like mine did when I grenaded mine. When I would turn the tire it would take about a 1/8 of a turn before the driveshaft would engage. For me it was the Posi that was split in half and allowing play between the ring and pinion which led ot me breaking teeth off the ring and pinion.

I hate to say it but I think it's most definately inside the rear. Pull the cover off and have a friend turn the rear tire until you hear something out of the ordinary.

**Wesman** · 10-24-2010, 05:54 PM

Originally Posted by bberretta

Sounds almost like mine did when I grenaded mine. When I would turn the tire it would take about a 1/8 of a turn before the driveshaft would engage. For me it was the Posi that was split in half and allowing play between the ring and pinion which led ot me breaking teeth off the ring and pinion.

I hate to say it but I think it's most definately inside the rear. Pull the cover off and have a friend turn the rear tire until you hear something out of the ordinary.

I agree, it does sound internal to the differential.

I've had it apart twice already. Everything looks, feels, and checks out normal. Backlash is good, pinion preload is good (unless the nut somehow backed off and lost preload) and side bearing preload is tight. Mesh pattern checks out, and the diff is practically brand new, its a Detroit TrueTrac.

When I turn the wheels or driveshaft by hand, its dead quiet, no bad noises or excessive lash/play at all.

I appreciate the feedback.

**bberretta** · 10-24-2010, 08:18 PM

How does the u-joint feel?

I doubt the pinion nut is backing off, but I've seen stranger! From the video it sounds like its coming from the front- pinion bearing/yoke/u-joint. When you put a load on it, how does it behave?

**Wesman** · 10-25-2010, 02:01 PM

Originally Posted by bberretta

How does the u-joint feel?

I doubt the pinion nut is backing off, but I've seen stranger! From the video it sounds like its coming from the front- pinion bearing/yoke/u-joint. When you put a load on it, how does it behave?

I agree, it was hard to tell by ear but on the camera it sounds like the noise is concentrated by the pinion. U-joint was good last I checked, but who knows. Looks like its time to put it on the lift again and re-check the u-joint and pinion bearings. Its really starting to piss me off!!