That was my first thought as well.
Feb 23, 2015, 06:45 PM
Last edit by: IB Advertising
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Thumping Sound in Rear End
Thread Starter
Burning Brakes
Joined: Jun 2003
Posts: 1,079
Likes: 1
From: Niagara Falls ON
Thumping Sound in Rear End
I have had a thumping sound in the rear of my 1976 for a while. I have been checking everything to see what it could be. Tires don't seem to be the problem. I have replaced u-joints and the sound is still there. I have checked the brakes and the sound remains. I have check wheel bearings and the sound is still there.
When I replaced the u-joints on the drivers side I did find something that I thought was strange...something that may be the source. When I took off the bolts on the outer u-joint I didn't need to make any adjustments to the suspension to have it slip off. There was enough space there for the entire half shaft to be lowered. This seems to suggest that the alignment is way off. Could this possibly be the source of a thumping noise? I wasn't sure if the suspension was pulling in and out while driving, causing a thumping noise. I do plan on doing an alignment sooner rather than later.
Also, should I get new tires first or can the alignment be done with the old ones on?
Any thoughts?
When I replaced the u-joints on the drivers side I did find something that I thought was strange...something that may be the source. When I took off the bolts on the outer u-joint I didn't need to make any adjustments to the suspension to have it slip off. There was enough space there for the entire half shaft to be lowered. This seems to suggest that the alignment is way off. Could this possibly be the source of a thumping noise? I wasn't sure if the suspension was pulling in and out while driving, causing a thumping noise. I do plan on doing an alignment sooner rather than later.
Also, should I get new tires first or can the alignment be done with the old ones on?
Any thoughts?
Melting Slicks
Joined: Jul 2010
Posts: 2,503
Likes: 33
From: McGrady NC
St. Jude Donor '15-'16
Is it a consistent thump like a rotational noise or an occasional thump? I would check the shocks and the stub axles to make sure the C-clips are still in place. So many bad things cause more of a clunk instead of a thump.
Thread Starter
Burning Brakes
Joined: Jun 2003
Posts: 1,079
Likes: 1
From: Niagara Falls ON
It seems to be a rotational noise. I do need to inspect the transmission mount, just in case but need to know if the face that I can easily pull the half shaft off once disconnected could be the issue...it certainly is something that needs attention.
Melting Slicks
Joined: Jul 2009
Posts: 3,264
Likes: 3
From: Vero Beach FL
Thread Starter
Burning Brakes
Joined: Jun 2003
Posts: 1,079
Likes: 1
From: Niagara Falls ON
I decided to try something different. Since it felt like the thumping was on the drivers side I took off my spare tire from the carrier, filled it with air (good excuse to check it out), and put it on the drivers side. I went for a drive and the thumping was gone. I looked at the tire that had been on it but couldn`t see or feel any problems with it anywhere.
I guess the solution to the problem was right in front of me.
I guess the solution to the problem was right in front of me.
3rd Gear
Joined: Jan 2009
Posts: 3
Likes: 0
Hey guys. I've got a '78 on which I've just replaced/rebuilt pretty much everything in the rear suspension. I had a small thumping noise before the rebuild similar to what the OP suggests. I got it back on the road this past weekend and the thumping noise is even louder. Here is a video if the noise:
I've had people suggest the snubber bushing, but I replaced that. My tires are also practically new. I'm going to mount a GoPro camera under the backend and drive down the road a few times this weekend. I'm hoping the video will help me spot something that will explain it. Suggestions are certainly welcome
Thanks.
I've had people suggest the snubber bushing, but I replaced that. My tires are also practically new. I'm going to mount a GoPro camera under the backend and drive down the road a few times this weekend. I'm hoping the video will help me spot something that will explain it. Suggestions are certainly welcome
Thanks.
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Instructor
Joined: Apr 2013
Posts: 156
Likes: 0
From: Reisterstown Maryland
I've got an occasional thumping noise on my 76 as well. Happens mostly when shifting after engaging each gear gear. Doesn't sound too sinister but I suspect a motor or tranny mount. I tried googling the differential hold down bushing with no luck. Is there a "sticky" regarding this issue that I can refer to?
Thanks,
Diesel
Thanks,
Diesel
Melting Slicks
Joined: Jul 2009
Posts: 3,264
Likes: 3
From: Vero Beach FL
I've got an occasional thumping noise on my 76 as well. Happens mostly when shifting after engaging each gear gear. Doesn't sound too sinister but I suspect a motor or tranny mount. I tried googling the differential hold down bushing with no luck. Is there a "sticky" regarding this issue that I can refer to?
Thanks,
Diesel
Thanks,
Diesel
