Bumping noise in bed.

El_Ron84 · Posted: Fri Jul 04, 2008 1:53 pm Post subject: Bumping noise in bed.

There is a bumping going on in the rear bed that is driving me crazy. I have been trying to narrow it down for about 8 months and no luck. the car is riding on air shocks. I have lowered and lifted them and I still get the sam effect. The bumping only occurs on one side. Has anyone had this same issue or know of something that I can look at to make this stop. Also rear bump stop looks like it is still brand new.

Thanks in Advance

LeoC2 · Posted: Fri Jul 04, 2008 1:57 pm Post subject:

Check all suspension components, the bump may not be something hitting it could be something loose.

I'd also check your exhaust system, that's a likely culprit.
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Seraphx7 · Wrench Necoa #: 5625 Joined: Jun 16, 2005 Posts: 26

I had a Bump as well and it turned out to be the differential. More of a knock than a bump when I would let off the gas. I had a locking diff at the time. Put in a posi.

El_Ron84 · Posted: Fri Jul 04, 2008 8:32 pm Post subject:

So far this noise only occurs when I am on bumpy roads or freeways. I was under the car for quite some time this morning looking for anything that might be wrong; nothing. The one thing I did find that on the springs was what I think was the original tag when the car was manufactured. I googled the part number and it was for my model car. So my hope is this is where some or most of my problem lies. I have new springs in the garage I will be making some time to get them on soon. I am ready for some smooth sailing.

Ron

LINY · Posted: Wed Jul 09, 2008 7:16 am Post subject:

I bet the frame rail is touching the body at the location just forward of the rear wheel on the drivers side. I found this to be the case on both of my 87's.
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hel98 · Posted: Wed Jul 09, 2008 4:17 pm Post subject:

Could be the coils are binding. It's more noticeable with variable rate springs. GM had a service bulletin in the mid 80s for a thumping noise in the rear of G and B cars. The fix was to index the springs so the end of the bottom coil faced to the right side of the car. Put your jackstands under the frame and let the rear end hang. You should be able to turn the springs. If not, take the shocks off the lower mount for some more slack.
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El_Ron84 · Posted: Fri Jul 11, 2008 9:58 pm Post subject:

Thanks for the tips I will look into both of them this weekend and keep you posted.

Ron

szonk · Posted: Sat Jul 12, 2008 2:50 pm Post subject:

Might want to check body mounts too, mine had some clunking during cornering from worn bed to frame rubber.
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El_Ron84 · Posted: Sat Jul 12, 2008 5:04 pm Post subject:

Liny you must be psychic the noise was coming from my driver side and yes there was contact between the frame and bed rail. I took Hel's advice and turned my springs, yes the springs are variable rate. Turned them to the the right and I got a little extra clearance. Test drove the bumping decreased but it is still there. Next will be to go back under and tigthen all the body mounts. You can see that the spring on the driver side is shot so I think that is a big part of the problem. Ordered coil islolators on Friday, springs are in garage, I hope to get the springs installed in the next weekend or two then maybe I can put this issue to rest and move on to next crisis. Thanks for all the input you all helped me narrow this thing down. Will keep you posted.

Thanks,
Ron

texasjim · Posted: Sat Jul 12, 2008 9:43 pm Post subject: things that go bump in the night

probably not your prob. but I crawled under my truck a zillion times trying to find my bump it turned out that my bed liner had shrunk up about 2 inches over time and was sliding back hitting tailgate on accel. and would slid forward and hit back of box damn simple like to have drove me nuts Hope you find your bump in the night jim

Larry 3 · Posted: Fri Jul 25, 2008 7:40 pm Post subject:

Well, I have a good one.
I had a light metallic clicking/clunking in the back and searched all the obvious things (exhaust, body mounts, shock mounts, bumper mounts, gas tank mounts)
If I hit the gas tank with a rubber mallet I would hear that noise. I'm thinking I need new rubber above the tank. Drop the tank, no rubber, so I add some (no rubber needed by the way). Still got it. So I decide it's a baffle or some other part in the tank has come loose and I need a new tank.
Since I'm in a major modification project, that gets pushed aside for later.
So, I installed my 9" Ford rear with many mods including air bags and while installing the air filler fittings under my gas cap door, I bumped the GAS CAP!! And that was my noise. A WORN OUT LOOSE GAS CAP!
Is my face RED? Embarassed

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El_Ron84 · Posted: Sat Nov 08, 2008 11:45 pm Post subject:

Well I finally got around to getting all my front end work done, including new shocks and springs all around. She rides like a dream, what a difference. I was cruising along not hearing the old bumping noise thinking it was a thing of the past, when all of a sudden it came back. It was not as loud as before but it is still there, damn. Sounds like something is just a little loose, just loose enough to get on my nerves. I was caught off guard but I will be on the hunt for this noise in the morning. I am thinking more and more it is the body mounts like was suggested in earlier posts.