etekberg

Does this sound like an axle noise to you? Video:



History is I bought a 2003 C5 Z06 a few weeks ago. It has a number of problems, including an intermittent grinding noise from the rear. The transmission was just rebuilt, new torque tube bearings installed, and a new differential was installed prior to my purchase. It was obviously slapped together in a hurry without much care.

The noise is present with the rear wheels rolling, even with the engine off in neutral, so I figure it must be a problem from the output shaft back.

I put it on the lift and saw a leaking right axle. But I'm not positive that is the source of the noise. What do you think?


Leaky Axle:




Hmmm...I doubt this clamp is supposed to be empty.


Somehow I think something else is supposed to be in this spacer?


Missing bolt.


Loose mid pipe


Missing torque tube bolt.


O2 sensor wiring burning on header.


AC hose sleeve touching header.

Mattie Num Nums

Looks like someone was burning the midnight oil before they sold this. Either way its still an amazing car keep your head up. I am sure someone here can give you all the info you need.

Bill Curlee

You have more exhaust leaks than I can count,, Sounds like a farm tractor

I would get the exhaust properly sealed up and we can get a better idea of what it sounds like

I did hear a bad noise when the wheels coasted down and to me it sounded like a bad wheel bearing. Grab the wheel in the 12:00 & 6:00 position and push /pull
There should be no slop or free play. Same for the front wheels.

Your CV Joint boots also look damaged. Wipe off the grease and see if the boots are split.. If so, replace the CV joint with a rebuilt unit form the auto parts stores.

BC

etekberg

Yes, there are. Each over the axle pipe has a hole in it from rubbing on the axle shafts. I'm not sure how it is possible, or if it was from the presuambly catastrophic event that caused the prior owner to rebuild the trans and replace the diff.

That was the part I wanted you to hear. But the noise is definitely not coming from the spindle areas. It is definitely towards the center (I'm thinking diff or trans).

There's no slop that I can tell, for what it's worth.

The right shaft inner boot is obviously split and spewing grease everywhere. However, I'm wondering if it is the source of the noise or not (I'm thinking not).

Bill Curlee

Try this:

Jack up the rear. Have some one HOLD one rear wheel. See if you can turn the other one.
If everything is working correctly, you shouldnt be able rotate it to or it should take a lot of force to move it AND, there shouldnt be any slop.

jsbzoh6

You'd be amazed how sound carries with these things. I don't have any sound while I'm at work, but I ended up having a bad front right wheel bearing that caused what I (and 275$ later, a Corvette "Speciality" shop) KNEW was a bad diff. I got the diff rebuilt and the noise was still there. I eventually said "screw it", and replaced all the wheel bearings. Smooth sailing from there.

Soul per4mance

My noise similar a few yrs ago was a rear passenger wheel bearing that had went bad.

olbear1962

I would agree -wheel bearing.
Also, would change out that damaged CV boot!

etekberg

Thanks for the help. I'm surprised everyone is saying wheel bearing. I'm not detecting anything on the wheel movement tests, but I've had several bad wheel bearings in my lifetime and never once detected it that way.

None of the bad wheel bearings I've had before sounded anything like this. But those were on other cars - this is my first time working on my own vette . This noise is awful and my gut is saying transmission, but I'd really like to have a plan of action before I rip the driveline apart.

I fixed the exhaust leaks and made another video. I move the phone around so hopefully you can tell that the noise is much louder around the transmission/differential area.

jsbzoh6

If the sound is that clunking sound, it's definitely not a wheel bearing.

DIXZ

It really doesn't sound like a wheel bearing to me. Try using a stethoscope or the screwdriver to the ear trick and see if you can isolate a component. To me it sounds like you have spare parts in the differential, but I am probably misreading the video.

etekberg

I don't think you're misreading it. That's what it sounds like to me too. I think I got a ****** rebuild job.

I'll try a stethoscope, if I can figure out where to get one quick locally

Bill Curlee

Car on lift, ENGINE OFF in first gear: rotate one of the rear wheels CW and then CCW. See if there is ANY lost motion. There should be very little. Then check the other one.

What does the drive train sound like with the car on the lift, trans in N engine running clutch out?? And then clutch IN.

Theres a BUNCH of lost motion somewhere! My first guess would be the rubber couplers in the torque tube.

BC

etekberg

There's about 1" circumference (along the tire) play in the left side, and about 1/2" in the right. So what does that reveal?

Small amount of noise, but not the same noise.
Minor to insignificant change with/without clutch.

The main noise happens with the engine off, in neutral, coasting down the highway. Drive shaft would not be rotating at that point, so I don't think that's the source. I think it's output shaft of the transmission back.

Got a stethoscope, and it's still hard to tell if it's differential or transmission, but I think it was loudest when pressed up against the rear of the transmission case.

BTW I now agree that a wheel bearing is likely bad, but I think it's not the main problem - just another one among the 99.

Bill Curlee

Well. You are probably NOT going to like what I am going to tell you to do:

I would disassemble the entire thing from the bell housing back and reinspect ALL the work.
With all the HACK jobs that you posted, I wouldn't trust ANYTHING.

Its sooner or later going to POP and leave you stranded and BROKE! Fix the issue before it goes catastrophic

Remove the trans/Diff as one piece from the TT and then the TT

If it were me,, I would even remove the clutch. and male sure that the Flywheel bolts are properly torqued and locktited in mplace...

BC

etekberg

I had already decided to do that. Except I'm thinking of dropping the engine with it (need to put in a milder cam at the minimum). The question is, assuming nothing obvious is seen after removal, what gets opened up after it's out? The trans or the diff?

Bill Curlee

The Differential is EASY to open and inspect. Here are two or three post that you should take a look at. I did the C6 up-grade and it worked out excellent.

- C5, ragtopws6 , Upgrading your C5 rear with C6 Z06 guts, : http://forums.corvetteforum.com/c5-g...-z06-guts.html


- C5, Its_Go_Time, Output Shaft Install - Left and Right: http://forums.corvetteforum.com/c5-t...post1573407966

- C5 ragtopws6, T-56 Build (what’s in my tyranny?) : http://forums.corvetteforum.com/nort...-smoother.html
-


The trans can be checked for lost motion after you separate it from the Diff and TT

I recommend taking the TT apart and checking the bearings and rubber couplers

BC

mchicia1

Did you ever figure this out?

etekberg

I'm still dropping the engine and driveline together for my first time. I've got an L92 engine on the way. I work super-slow.

merlot566jka

I said throw out bearing... When we pulled the trans the second time

FWIW I did pull and put in the trans/rear on this car twice. I was there when it blew. I know the car well.

I have some exhaust hangers that I wanted to put on there.

It was never my car, but I know a ton about it. If you want to PM me, maybe we can work together to find the problem.

And just to throw it out there, the guy that sold you the car is a standup guy. I was fairly sure he told you about all of this when you bought it...?