What is this noise?? rear end ??

[5abivt]

Ok So I was just under my z to adjust my anti rattle y pipe clamp and noticed when I was jacking up the car halfway I heard a clunkish sort of noise from the rear. This is the same noise I always hear slowing to a stop wether it be in a straight line or turning from the rear end usually at 5mph or less.

After I adjusted the clamp I lowered the car and grabbed my right rear tire at 9 and 3 and pushed and pulled a few times... clunk clunk clunk... Something is loose or has play back there. ANy ideas??

Brief history... I swapped the original rotors when I picked up the car and used the BFH technique to smash and shatter them off. Not sure if the z has rear wheel bearings or whatever plays the same role in a rear axle but may that be the cause?

I did install an on car adjustable PHB (UMI). And the bolts are tight at both ends. I can honestly say I started noticing clunking noises after I installed the bar. Not sure if maybe I was just listening more closely for anything being loose or if in fact something is loose back there. I put tape around the adjustment bolts I'll pull it off tomorrow and make sure they're still tight.

ANy suggestions or things I can check?

[402 Guru]

Ok So I was just under my z to adjust my anti rattle y pipe clamp and noticed when I was jacking up the car halfway I heard a clunkish sort of noise from the rear. This is the same noise I always hear slowing to a stop wether it be in a straight line or turning from the rear end usually at 5mph or less.

After I adjusted the clamp I lowered the car and grabbed my right rear tire at 9 and 3 and pushed and pulled a few times... clunk clunk clunk... Something is loose or has play back there. ANy ideas??

Brief history... I swapped the original rotors when I picked up the car and used the BFH technique to smash and shatter them off. Not sure if the z has rear wheel bearings or whatever plays the same role in a rear axle but may that be the cause?

I did install an on car adjustable PHB (UMI). And the bolts are tight at both ends. I can honestly say I started noticing clunking noises after I installed the bar. Not sure if maybe I was just listening more closely for anything being loose or if in fact something is loose back there. I put tape around the adjustment bolts I'll pull it off tomorrow and make sure they're still tight.

ANy suggestions or things I can check?

it could be many things in the rear if you have Torque bar it would help to see how much torque is on your lca's are they stock ?
make sure your Lower control arms are tight ( lca's) if thats not it. then u could very well of broken the bearing/ messed them up when did u change the rotors how long since u did the rotor change?

[5abivt]

Appreciate the reply. i did the rotor and wheels when I picked up the car in lat emay or June I forget. I did the panhard a few months later. rear control arms are stock. I did notice because the bracket for the pass side phb was bent I had to push the new adjustable phb forward a bit to get it in the bent bracket.

I'm going to try tomorrow to put the car up and see if I can bend it back. I'll also Check all the bolts to see if everything is tight. Are the adjustable phb adjustment bolts notorious for loosening?

[c5z28]

Appreciate the reply. i did the rotor and wheels when I picked up the car in lat emay or June I forget. I did the panhard a few months later. rear control arms are stock. I did notice because the bracket for the pass side phb was bent I had to push the new adjustable phb forward a bit to get it in the bent bracket.

I'm going to try tomorrow to put the car up and see if I can bend it back. I'll also Check all the bolts to see if everything is tight. Are the adjustable phb adjustment bolts notorious for loosening?

mine loosened but it wouldn't clunk if the rear end is jacked up and spinning the wheels by hand. Easy to tell get under there and hit phb with your fist if it moves it's loose.

[Smittro]

Ok So I was just under my z to adjust my anti rattle y pipe clamp and noticed when I was jacking up the car halfway I heard a clunkish sort of noise from the rear. This is the same noise I always hear slowing to a stop wether it be in a straight line or turning from the rear end usually at 5mph or less.

After I adjusted the clamp I lowered the car and grabbed my right rear tire at 9 and 3 and pushed and pulled a few times... clunk clunk clunk... Something is loose or has play back there. ANy ideas??

Brief history... I swapped the original rotors when I picked up the car and used the BFH technique to smash and shatter them off. Not sure if the z has rear wheel bearings or whatever plays the same role in a rear axle but may that be the cause?

I did install an on car adjustable PHB (UMI). And the bolts are tight at both ends. I can honestly say I started noticing clunking noises after I installed the bar. Not sure if maybe I was just listening more closely for anything being loose or if in fact something is loose back there. I put tape around the adjustment bolts I'll pull it off tomorrow and make sure they're still tight.

ANy suggestions or things I can check?

Just a stab in the dark here. But when you did this "push/pull" did the wheel move in and out? If so how much? Any wetness @ the ends of the axle tubes? If so possibly a bearing letting go and in turn the seal maybe starting to leak. Limited slip? If so possibly the spider/planetary gear pin may be heavily worn allowing for movement. Shocks old? If so a dry shock may rattle/clunk if moved around.
Lateral torque arm upper bushing maybe shot, or have a broken/rusted off bolt, upper portion of the mount maybe rotted aswell. Check upper shock mounts for damage/excessive rust, broken, or loose king bolt/nut. Check the calipers for excessive play, and loose bolts. How about your exhaust system @ the rear. I don't know your setup but your exhaust maybe "bumping" the body somewhere when you shook it.. Just a few ideas.. Good luck..

[402 Guru]

Appreciate the reply. i did the rotor and wheels when I picked up the car in lat emay or June I forget. I did the panhard a few months later. rear control arms are stock. I did notice because the bracket for the pass side phb was bent I had to push the new adjustable phb forward a bit to get it in the bent bracket.

I'm going to try tomorrow to put the car up and see if I can bend it back. I'll also Check all the bolts to see if everything is tight. Are the adjustable phb adjustment bolts notorious for loosening?

No bolts will ever move as long as you have a Sterile ( clean ) suface that you apply blue loctight onto. red loctight if you never plan on moving the bolts agian unless youre using a a compressed air gun where is usually only available ( if either you work at a shop or )if u have a compressed air tank at your house and a $400 air gun but basic hand tools is all you need to put your panhardbar and to check the torque of your lca's,now i sayed to use a torque bar to check the torque on the lca's because thats the only way to tell how much force is actually on that bolt ( for example our stock torque arms are Notorious for snapping because of the cheap stamped steal just like your Lower control arms or (LCA's) are stamped steel. where i built my car i applied locktight to every bolt onto my car took every bolt off and replaced it with stainless steel bolts and blue locktight for every bolt as i have never had a problem with my car . let me know what your outcome with checking all of your bolts torque, also check out your Torque arm mount they are also notorious for snapping and causing all kinds of drivetrain problems

[402 Guru]

if you can some how either pound that bracket streight by taking it off the car check the bolts on the bracket also imo. you have to check your structrual integrity before even driving saftey is the #1 concern in the rear of the car if you rush things you will end up paying for it later . .

[Smittro]

No bolts will ever move as long as you have a Sterile ( clean ) suface that you apply blue loctight onto. red loctight if you never plan on moving the bolts agian unless youre using a a compressed air gun where is usually only available ( if either you work at a shop or )if u have a compressed air tank at your house and a $400 air gun but basic hand tools is all you need to put your panhardbar and to check the torque of your lca's,now i sayed to use a torque bar to check the torque on the lca's because thats the only way to tell how much force is actually on that bolt ( for example our stock torque arms are Notorious for snapping because of the cheap stamped steal just like your Lower control arms or (LCA's) are stamped steel. where i built my car i applied locktight to every bolt onto my car took every bolt off and replaced it with stainless steel bolts and blue locktight for every bolt as i have never had a problem with my car . let me know what your outcome with checking all of your bolts torque, also check out your orque arm mount they are also notorious for snapping and causing all kinds of drivetrain problems

I like your thinkin'..

To the OP, check the front torque arm mount too..

[5abivt]

Thanks guys! By torque arm you are referring to the bar that goes from the trans to the diff right? I know there is one more bar up there that looks like the stock panhard bar that goes across laterally not sure what that is called.

When I was moving the tire... i was talking about the car right after I got out after driving home from work ! I got out of the car , grabbed the tire and shook it and I can hear knocking... kind of like a wheel bearing with a bit of play. i was surprised to hear anything.

I'm hitting the sack tomorrow the wifey is out of town so I can finally get under it and figure out if anything is loose. Also I'm not sure if the panhard bracket can be removed from the chassis last I remember its welded up there.

[Smittro]

Thanks guys! By torque arm you are referring to the bar that goes from the trans to the diff right? I know there is one more bar up there that looks like the stock panhard bar that goes across laterally not sure what that is called.

When I was moving the tire... i was talking about the car right after I got out after driving home from work ! I got out of the car , grabbed the tire and shook it and I can hear knocking... kind of like a wheel bearing with a bit of play. i was surprised to hear anything.

I'm hitting the sack tomorrow the wifey is out of town so I can finally get under it and figure out if anything is loose. Also I'm not sure if the panhard bracket can be removed from the chassis last I remember its welded up there.

Yes, and the other one above the panhard bar. Yes the mount is welded to the chassy but they like to rust. Especially on a DD..

[5abivt]

Thats my car lol .. i posted that in drivetrain too

[402 Guru]

Thats my car lol .. i posted that in drivetrain too

if thats your car then Theres one of your problems right there rust is like cancer once it starts it spreads to the other metal get a new mount from a wrecked 1 and it will be cheap if you can do it yourself that is

[5abivt]

Nothing wrong with the mount. the stock phb was rusted out that pic was after beating the death with a bfh out of the bolt holding it in. the sleeve was siezed on the bolt and caused the whole bracket to shift. I just beat on the other side with a bfh and i straightened the bracket ! I doubt its the cause of anything but I feel better now that it's straight.

Now I need to figure out an easy way to align the rear...

[5abivt]

UPDATE !!

Ok before I started I went out and stopped under a light on a downhill to try not to put too much weight on the rear of the car (lol). I laid down a nice 3-4 second burnout and then backed up and checked. 2 nice straight dark patches. wohoo !

After watching the leaf game (Yes we won!) I got down and measured my rear axle alignment and the same as I got before.. the left is 1mm or so inwards than the right. Not going to worry about such a small measurement I guess unless you guys can tell me otherwise.

I removed the right rear tire and spring. Got out the Big F*& Hammer and smacked it a bunch of times and I straightened out the bracket within seconds !! I feel much better now. I dropped the car, drove it around for a few minutes and reparked and checked the axle alignment. same 1mm so didnt bother with it.

EVerything else is tight. LCAs, Torque bar is tight and nothing visibly broken although it is covered in old fluid (dry). I pushed around the wheels and still heard that knocking sound it sounds exactly like busted wheel bearings on my vette but from what I've been told it's normal. Sounds like its coming from behind the rotors. I can hear it when i wiggle the steering wheel at 20 mph from the back sometimes.

that was long thanks for the help guys ! Not sure if I solved anything but did 2 things good.

1. straightened the bracket and I feel better.
2. Laid down some expensive rubber and know my posi isnt busted (I think) !

[2blk2drs]

took every bolt off and replaced it with stainless steel bolts and blue locktight for every bolt as i have never had a problem with my car .

Negative Ghostrider: Stainless Bolts have a strength of just above Gr. 5.

On a positive note, locktite also helps to keep the threads from seizing up.
If rust is a huge problem, you might try using antisieze and your favorite flavor of mechanical locking fastener.

Good Luck!

[402 Guru]

Negative Ghostrider: Stainless Bolts have a strength of just above Gr. 5.

On a positive note, locktite also helps to keep the threads from seizing up.
If rust is a huge problem, you might try using antisieze and your favorite flavor of mechanical locking fastener.

Good Luck!

ok i was refering to the interior bolts all exterior bols on my car are grade 9 do u feel better now and yes grade 9 bolts are worth the security plus i have my entire undercarrage and engine bay powdercoated red so there will never be problems with rust i was trying not to brag but you brought it out lol

[402 Guru]

UPDATE !!

Ok before I started I went out and stopped under a light on a downhill to try not to put too much weight on the rear of the car (lol). I laid down a nice 3-4 second burnout and then backed up and checked. 2 nice straight dark patches. wohoo !

After watching the leaf game (Yes we won!) I got down and measured my rear axle alignment and the same as I got before.. the left is 1mm or so inwards than the right. Not going to worry about such a small measurement I guess unless you guys can tell me otherwise.

I removed the right rear tire and spring. Got out the Big F*& Hammer and smacked it a bunch of times and I straightened out the bracket within seconds !! I feel much better now. I dropped the car, drove it around for a few minutes and reparked and checked the axle alignment. same 1mm so didnt bother with it.

EVerything else is tight. LCAs, Torque bar is tight and nothing visibly broken although it is covered in old fluid (dry). I pushed around the wheels and still heard that knocking sound it sounds exactly like busted wheel bearings on my vette but from what I've been told it's normal. Sounds like its coming from behind the rotors. I can hear it when i wiggle the steering wheel at 20 mph from the back sometimes.

that was long thanks for the help guys ! Not sure if I solved anything but did 2 things good.

1. straightened the bracket and I feel better.
2. Laid down some expensive rubber and know my posi isnt busted (I think) !

now its difficult to pinpoint problems in the rear end as a stethoscope will also pick up all residual noise if it sounds exactly like your wheel bearings like o your vette then order some new from jegs or pick some up from your local drivetrain shop should have what youre looking for and them some
Good luck and you know your posi isint broken if your burn out has both tires on the burnout when a posi is going out they are known for the infamous 1 wheel burnout