Did mine last year, more fun then I care to remember.
problem with an 84
Thread Starter
Melting Slicks
Joined: Oct 2005
Posts: 3,178
Likes: 5
From: Daleville Indiana
St. Jude Donor '08
problem with an 84
i have an 84 z51 auto that has a knocking sound coming from the rear end. i just replaced all the u joints and checked the bearings and does the annoying sound in forward and not reverse. what could it be? the car is in good shape and has 123,000 miles on it. i have done a lot of work on it and take good care of my bronze beauty, but my nerves are running short.
His nerves are running short, I'm the one thats has to work on this car.
His nerves are running short, I'm the one thats has to work on this car.
Last edited by Jonnymac; Aug 5, 2007 at 12:57 AM. Reason: He keeps calling me with ideas of what it could be.
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
Knock Knock....
You say you have a knocking sound coming from the rear end and you just replaced all the u joints. I'm guessing you changed not just the joints for the half shafts but the drive shaft as well? Was the knocking there before the joints were replaced?
If the knocking noise is new and you have relatively "new" U joints.....you might want to replace the "new" U joints I suspect that they are the cause of the knocking.
Many of the "new" U joints that I myself and other forum members', by testimonials, have used were problematic right from the get go - the joints started to fail shortly after they were installed.
Perhaps you can search other posted threads for a brand of U joint that people have more success with.
If the knocking noise is new and you have relatively "new" U joints.....you might want to replace the "new" U joints I suspect that they are the cause of the knocking.
Many of the "new" U joints that I myself and other forum members', by testimonials, have used were problematic right from the get go - the joints started to fail shortly after they were installed.
Perhaps you can search other posted threads for a brand of U joint that people have more success with.
Thread Starter
Melting Slicks
Joined: Oct 2005
Posts: 3,178
Likes: 5
From: Daleville Indiana
St. Jude Donor '08
The 84 is a friends ride. He told me the knocking sound started a week ago, but the rear has been make some noise since he bought it. I just replaced the drive shaft U-joints tonight, the half-shaft u joints were replaced by someone else last month, I assume the job was done right. When you turn the drive shaft by hand the sound comes from the dif yoke. The wheel bearings are not the best and when I check the spindle nuts, they were easy to loosen and remove. What gets me is that it only makes the sound in drive not reverse. Would a bad u joint do this?
Thanks
Thanks
Last edited by Jonnymac; Aug 5, 2007 at 02:07 PM.
Thread Starter
Melting Slicks
Joined: Oct 2005
Posts: 3,178
Likes: 5
From: Daleville Indiana
St. Jude Donor '08
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
The U joint failures that I had you could only hear a light ticking sound under hard "forward" acceleration the shafts had no slop in them at that time. When the same ticking turned into a knocking sound I could rock the car back and forth and hear and audible pop sound from the joints and then you could see/feel the shafts bounce.
I hear you on the wheel bearing change out thing....I've had bad wheel bearings in the past but they never ticked they just made the rear end feel loose and caused the pads to really rub on the rotors.
You could pop out the shafts one at a time and check for slop in the rear end and gears.
If your not sure what the noise and don't want to swap parts out fun then just wait 'till the knocking gets worse...it will be easier to find then....just make sure your paid up on your AAA membership dues.
I hear you on the wheel bearing change out thing....I've had bad wheel bearings in the past but they never ticked they just made the rear end feel loose and caused the pads to really rub on the rotors.
You could pop out the shafts one at a time and check for slop in the rear end and gears.
If your not sure what the noise and don't want to swap parts out fun then just wait 'till the knocking gets worse...it will be easier to find then....just make sure your paid up on your AAA membership dues.
Le Mans Master
Joined: May 2006
Posts: 9,226
Likes: 9
From: Irvine Ca
I'm thinking to check the C-Beam and make sure it is tight.
I have heard about the rear end gears being screwy as well, but what i heard was just a blip and I can't tell you exactly......maybe the Gurus will come along and add to that story.
I have heard about the rear end gears being screwy as well, but what i heard was just a blip and I can't tell you exactly......maybe the Gurus will come along and add to that story.
Thread Starter
Melting Slicks
Joined: Oct 2005
Posts: 3,178
Likes: 5
From: Daleville Indiana
St. Jude Donor '08
C-beam was tight when I removed it and was torqued to spec. Going over some old post it could be the washer on the back of the bearing. Or just the way the 84s were built. "there was a service bulletin years ago regarding this issue. How I found out was I posted a question about why the spare half shafts I bought on ebay had some small threaded plugs inserted in the shafts. Apparently a fix for the noise was to drill a small hole in the tube portion of the half shaft, squirt in some oil, and then plug the hole with a small allen head set screw. My guess, and I am open to correction here, is that the oil film was to soften up the impact noise when the half shaft internal yoke/tube interface twisted slightly under load."
This is what the wheel bearing on my 95 looked like, never did make any noise.
This is what the wheel bearing on my 95 looked like, never did make any noise.
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