A Challange
Thread Starter
Safety Car
Joined: Oct 2005
Posts: 3,570
Likes: 1
From: Algonac Michigan
A Challange
Hears my problem and a challenge for the forum...
I have a recently developed noise coming from the rear of my '69. Also the car has recently been restored, nut and bolt(mostly). It has been running great for 3 mos. So anyway, yesterday I was Coming home from the Woodward Dream Cruise and I heard what I perceived as a grumbling coming from the left rear. It may have also been coming from the right rear, but I couldn't tell due to the air and road noise. It is a convertible.
Today I attempt to track down the noise by first getting the car in the air and putting stands under the lower shock mounts.
I then start the car and put it in 5th gear and listen at the rear. I DO hear noise from the L/R but a much louder noise coming from the R/R.
The noise is a grumbling with an occasional thunk!
So I remove the R/R half shaft to isolate the noise and I start the car.
This time I hear nothing from the L/R but the rear end is making a lot of noise!
I then remove the half shaft on the L/side, and start the car.
THERE IS NO NOISE COMING FROM THE REAR END AT ALL!!!!!!!!!!!
All I hear from the rear is a whirring sound that I perceive to be normal.
Am I missing something here?????
I have a recently developed noise coming from the rear of my '69. Also the car has recently been restored, nut and bolt(mostly). It has been running great for 3 mos. So anyway, yesterday I was Coming home from the Woodward Dream Cruise and I heard what I perceived as a grumbling coming from the left rear. It may have also been coming from the right rear, but I couldn't tell due to the air and road noise. It is a convertible.
Today I attempt to track down the noise by first getting the car in the air and putting stands under the lower shock mounts.
I then start the car and put it in 5th gear and listen at the rear. I DO hear noise from the L/R but a much louder noise coming from the R/R.
The noise is a grumbling with an occasional thunk!
So I remove the R/R half shaft to isolate the noise and I start the car.
This time I hear nothing from the L/R but the rear end is making a lot of noise!
I then remove the half shaft on the L/side, and start the car.
THERE IS NO NOISE COMING FROM THE REAR END AT ALL!!!!!!!!!!!
All I hear from the rear is a whirring sound that I perceive to be normal.
Am I missing something here?????
Last edited by sly vette; Aug 15, 2007 at 04:17 PM.
Thread Starter
Safety Car
Joined: Oct 2005
Posts: 3,570
Likes: 1
From: Algonac Michigan
I know it has only been a short time since my original post, but I am setting here dirty with nothing to do.
Do you think the rear is bad, but doesnt make noise with no load applied.
When I heard the noise , it did seem to be slightly louder on accel.
Anyone......SIXX????? NORVAL??????? GTR1999???? BERNIE??????
ANYBODY????
I'm going out to remove the rotors from the rears, and see if there is anything strange there.
Do you think the rear is bad, but doesnt make noise with no load applied.
When I heard the noise , it did seem to be slightly louder on accel.
Anyone......SIXX????? NORVAL??????? GTR1999???? BERNIE??????
ANYBODY????
I'm going out to remove the rotors from the rears, and see if there is anything strange there.
Last edited by sly vette; Aug 15, 2007 at 04:20 PM.
Melting Slicks
Joined: Jan 2004
Posts: 3,247
Likes: 210
From: Detroit MI
If you're that far into it, try disconnecting the driveshaft from the pinion and turn the pinion by hand, see if you can feel anything strange. I've gone through a few ring and pinion sets, you should be able to feel if it's missing teeth or not. Was the gear set replaced when you restored it?
Otherwise I'd be checking U-joints, bearings and spindles for play.
Otherwise I'd be checking U-joints, bearings and spindles for play.
Thread Starter
Safety Car
Joined: Oct 2005
Posts: 3,570
Likes: 1
From: Algonac Michigan
O.K. Hears the story....
TRAILING ARMS: Both have been checked and the run out on the L/side is .004. On the R/side the run out is .002. Neither spindle spins freely, but they turn by hand with resistance. All is smooth and feels normal in my estimation.
REAR END: I started it again and a slight noise could be heard, and the noise was amplified when I checked it with a broom stick. Sounded like a low grumble, kinda like marbles in water. The noise lessened as the rear lube heated, I believe. There is no slop between the half shaft yolks and the pinion on either side.
At this point I feel there is a problem in the rear. Mainly due to the fact that the rear spindles turn by hand with resistance. Less than it would take to open a jar of pickles.
TRAILING ARMS: Both have been checked and the run out on the L/side is .004. On the R/side the run out is .002. Neither spindle spins freely, but they turn by hand with resistance. All is smooth and feels normal in my estimation.
REAR END: I started it again and a slight noise could be heard, and the noise was amplified when I checked it with a broom stick. Sounded like a low grumble, kinda like marbles in water. The noise lessened as the rear lube heated, I believe. There is no slop between the half shaft yolks and the pinion on either side.
At this point I feel there is a problem in the rear. Mainly due to the fact that the rear spindles turn by hand with resistance. Less than it would take to open a jar of pickles.
Thread Starter
Safety Car
Joined: Oct 2005
Posts: 3,570
Likes: 1
From: Algonac Michigan
O.K. I let the rear go to ambient temp. and started it up. I crawled underneath and put my ear directly on the rear end. I heard what sounded like sandpaper rubbing.
I am going to take the pig with me to work where I will remove the rear cover and take a peek.
I am going to take the pig with me to work where I will remove the rear cover and take a peek.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Did you have it idling in 5th gear? I would think it would be bucking in the rear.Are you sure your not having some clutch chatter?I have better luck listening for rear noises setting idle to 1500 and in 2nd gear and the park brake pulled on a couple clicks.Just seems to be smoother.
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Le Mans Master
Joined: Jan 2000
Posts: 8,918
Likes: 27
From: New Hill NC
Rear end side bearings will cause a low rumble that gets louder with car speed. Because they are running in oil, they are hard to detect untill they get very bad. This sounds like that assuming that the wheel bearings are really good.
Le Mans Master
Joined: May 2006
Posts: 7,708
Likes: 266
From: indy indiana
is there any difference in the noise when you are driving..between giving it gas, or coasting? Any clunks,clicks,thuds? If no is the answer to all the above, then yes, its in one the bearing, be it carrier, side or u-joint cup. If its yes, I would suspect Ring and Pinon issues.
Thread Starter
Safety Car
Joined: Oct 2005
Posts: 3,570
Likes: 1
From: Algonac Michigan
One thing nice about working on this car now is that every thing is nice and clean and when I take something apart I don't have to wrestle with rusted bolts or greasy parts!
Melting Slicks
Joined: Oct 2004
Posts: 2,662
Likes: 8
From: Knoxville Tennessee
Sly,
I hate to see you are having a problem. There are several things that could be causing your problem, more that likely the bearings are going. Since you have the diff out, if it were mine, I would go ahead and rebuild it. If you don't have the tools, there are several vendors that do a great job. If I remember correctly, gtr1999 has a great rep building them, as well as, Volunteer Vets, Van Steel and others.
With the cover off, you should be able to tell if it is the bearings by rotating it slowly. Good luck!
Bernie
I hate to see you are having a problem. There are several things that could be causing your problem, more that likely the bearings are going. Since you have the diff out, if it were mine, I would go ahead and rebuild it. If you don't have the tools, there are several vendors that do a great job. If I remember correctly, gtr1999 has a great rep building them, as well as, Volunteer Vets, Van Steel and others.
With the cover off, you should be able to tell if it is the bearings by rotating it slowly. Good luck!
Bernie
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
First of all when you put the stands under the shock mounts did you kick the stands out so the half shafts would come down to near normal angle?If not the u-joints sometimes can bind a little.
Second without pressure on the tires the diff. yokes aren't held tight against the spider gear center pin and might thunk against the pin depending on u-joint position on each half shaft.
I do hope you find something inside that will explain but I honestly think you pulled it out prematurely.These rear ends when off the ground are sometimes pretty loose and do make some funny noises.
Second without pressure on the tires the diff. yokes aren't held tight against the spider gear center pin and might thunk against the pin depending on u-joint position on each half shaft.
I do hope you find something inside that will explain but I honestly think you pulled it out prematurely.These rear ends when off the ground are sometimes pretty loose and do make some funny noises.
Racer
Joined: Mar 2006
Posts: 366
Likes: 1
From: Houston Texas
Le Mans Master
Joined: Jan 2000
Posts: 8,918
Likes: 27
From: New Hill NC
[QUOTE=sly vette;1561521447]Wheel bearings are good. no severe run out at the hubs, and they turn with minimal resistance.
QUOTE]
No DIS but, just because there is no runnout or no resistance in wheel bearings is no guarantee that the bearings are good. Many times they will have grease and still be set up fairly well, but will have chunks out of the race. The wear will be found on the upper section of the race and will growl when loaded with the cars weight.
QUOTE]
No DIS but, just because there is no runnout or no resistance in wheel bearings is no guarantee that the bearings are good. Many times they will have grease and still be set up fairly well, but will have chunks out of the race. The wear will be found on the upper section of the race and will growl when loaded with the cars weight.
Instructor
Joined: Jan 2007
Posts: 227
Likes: 0
From: Dallas Texas
When you take the rear cover off, look for: 1. blue bearings - excessive heat and friction will turn the bearings blue. 2. a spun race - take the bearing caps off and check to see if one of the side bearing races has spun. If so your case is shot. 3. Check the pattern on the ring gear - if the pattern is running off the edge your diff is worn out. 4. Check the clutch disks in the carrier - they might have been damaged by temperature or they could just be worn out. If you want to send me your diff I will take a look at it for you for free and tell you what you have. Duntov Motors 972-243-3838.
Instructor
Joined: Dec 2006
Posts: 105
Likes: 0
From: biloxi mississippi
when you restored the 69 did you replace the u-joint bolts with the heavyer duty connectors on some cars the new ones will be touching other parts and give this type noise. i have a fantom green 69 ragtop and i know this will happen.