Fixed rear end vibration

[John Robinson]

I have had a vibration in the back of my vette for some time now and thought it was tires but a new set did not change the vibration. I also had a clunk on the right side going over bumps. A couple of weeks ago just before I left for vacation I looked at the rear muffler hangers to check if they were tight. All during my vacation I kept thinking about how loose the bracket from the muffler through the rubber snubber was. Tonight I dropped the bracket off the rubber snubber and put a 1/4" piece of plastic between the bracket and the rubber snubber to tighen the hole around the bracket. I went for a shake down ride afterwords and the vibration is gone the clunk is gone and the car runs smooth and glides along the highway.

I was not sure if I should put this here or in general discussion but decided that I have read a lot of threads about rear end noise. (I am talking about from the car enough said.) and figured it was more of a fix then a discussion.

 

[Curious George]

I think you may have confirmed what I have been trying to figure out on my '92. After doing some exhaust work, I noticed a vibration during acceleration. I backed my car up on ramps and everything looked O.K. (nothing rubbing, etc) I had noticed that the stock mufflers were somewhat loose in their rubber mounting brackets, but did not think the muffler would vibrate that much to cause the "vibration" that I was feeling. I'll tighten those brackets up tomorrow and see what happens.

Thanks!
CG

 

[John Robinson]

I think you may have confirmed what I have been trying to figure out on my '92. After doing some exhaust work, I noticed a vibration during acceleration. I backed my car up on ramps and everything looked O.K. (nothing rubbing, etc) I had noticed that the stock mufflers were somewhat loose in their rubber mounting brackets, but did not think the muffler would vibrate that much to cause the "vibration" that I was feeling. I'll tighten those brackets up tomorrow and see what happens.

Thanks!
CG

Be sure to use a grease like a bearing grease to lubricate the L bracket so that it can move back and forth in the rubber slot. When you shim the bracket to tighten it up the L bracket will be very tight but it will move in and out under normal driving so it needs to have a grease to keep it from binding.

Good luck and I hope this works for you like it did for me.

 

[jam019]

Where you able to have a good vaction.

 

[John Robinson]

Where you able to have a good vaction.

Fantastic got to see my grandson graduate from High School and spent a couple of weeks with our daughter and family.

 

[tonyponykay]

oh do you have pic

hi,

wondering if you have pic of this L bracket thing and/or rear brackets that you put the 1/4 inch plastic on.

I just bought an 87 convertible vette, test drove it on smooth roads where there was a little clunking from the passenger side of the where the convertible top goes ... a wierd clunking noise and a slight vibration at undetermined speed, didnt matter what speed, seems to happen mostly on any bumps..

then driving home after purchase on highway with lots of bumps, almost shook me out of the car, thought it was breaking up at one point, it was shaking so bad that it went from shaking the rear end all the way up to the front seats shaking around. Feels almost exactly like a broken rear shock or a very loose exhaust. I will check that today when its light, last night in the dark I couldn't see.

thanks
tony

 

[John Robinson]

I don't know how the mufflers are fastened on your car but if you look up muffler brackets at Mid America Motor works you can see a picture of the bracket. It is located at the very end of the muffler and can be seen if you lay down at the back of the car and look at the muffler. Let me know if you need pictures of mine.

 

[tonyponykay]

i have it

i looked under and did look them as you suggested, good idea, i usually do just that, but i forgot this time....

they seem ok, the rubber is there, perhaps pretty hard rubber.. the rubber from the picture of the part at least is there, there is no rubber between the connector and muffler itself.. but there isn't any call for it on the part as it appears in website...

duno what the vibration is, could be just a bad tire if the owner didn't drive it for a long time, i have an email in to him to ask that.

it clunks the passenger side of the convertible top hatch..thats where the clunking is, but the cause of the clunking is some kind of vibration especially on bumps... doesn't do much of it on smooth road, although does a little bit, but when any kind of bump comes along, it shakes the whole rear end...

i'm going to try new shocks, check the bearings and hubs, etc and try to hunt it down.

thanks very much,

actualy after reading your original post i am confused by the "rubber snubber" .. i dont have one, and i didnt see that part on ecklers or mid america with a search of muffler ... my mufflers are bolted at the ends directly to a flange that is also bolted to the outside of the piece that shows up on the search for muffler related parts.. there is a piece of rubber that bolts between the top of that piece and the frame.. but thereis nothing that is sliding in and out of a rubber piece or anything that looks like a "rubber snubber"..

if you have time and don't mind too much, could you possible pop a photo up so I can make sure they did my mufflers correctly? I am starting to get highly suspicious that I'm missing something, the other poster also said something needs to be greased so that it slides inside the rubber.. I have no inside rubber or anything that slides...

thanks for the help,
tony

 

[Schrade]

I have had a vibration in the back of my vette for some time now and thought it was tires but a new set did not change the vibration. I also had a clunk on the right side going over bumps. A couple of weeks ago just before I left for vacation I looked at the rear muffler hangers to check if they were tight. All during my vacation I kept thinking about how loose the bracket from the muffler through the rubber snubber was. Tonight I dropped the bracket off the rubber snubber and put a 1/4" piece of plastic between the bracket and the rubber snubber to tighen the hole around the bracket. I went for a shake down ride afterwords and the vibration is gone the clunk is gone and the car runs smooth and glides along the highway.

I was not sure if I should put this here or in general discussion but decided that I have read a lot of threads about rear end noise. (I am talking about from the car enough said.) and figured it was more of a fix then a discussion.

Any pics of repair work? They're not against forum rules nope

 

[John Robinson]

Pictures

Hope these help you.

http://i285.photobucket.com/albums/ll72/John-68/Corvette005.jpg?t=1250276363

http://i285.photobucket.com/albums/ll72/John-68/Corvette006.jpg?t=1250276418

 

[tonyponykay]

checked my muffler hookup, looks correct

i think the only difference is that mine is 87 and yours is 93, reflected in the parts at midamerica ....

mine looks like its hooked up correctly and your pics helped a lot actually, the only difference being the piece between the muffler and the rubber insulated bracket.

my rattle is definitely now inside the convertible top hatch. Im thinking its the latch rattling inside the catch...so there must be some adjustment on that to stop that rattling.

putting new shocks on tomorrow probably and changing all brake pads soon after.

luv my new 87 vette, very torquish .. very fast.. lot different driving this than my 80 vette, which I also luv.

thanks very much for the help, at least i have eliminated one probably cause of the problem. matter of fact, Im starting to realize there isn't really any vibration, just the clatter of the hood latch or something in that area... by hood i mean the small hatch hood for the convertible top storage.

thanks much
tony

 

[92BlackVette]

With me, I have a clunking sound in my 92 (150k Miles) when I go in reverse and cut my wheels to the left or right. You can hear one tire unlocking as it reverses. It clicks again as soon as you straighten up. I have custom exhaust work where you guys are playing with the L brackets but it isn't that type of sound.... I am going to fix that when I go with a 3.45 --> 3.73

 

[tonyponykay]

found rascally rattle

wow, after much searching and researching (performed by very smart wifey) reading lots of forums about rattles on c4s ... wifey came up with a list of possible causes, when she mentioned fuel lines...oooo

i knew something was up. Sure enough, she came up with some pics of the area.. fuel lines coming from the fuel tank and moving across the frame area...had lost the black foam that keeps them from slapping against the frame... cut a piece of foam rubber and tied it to the lines, between the lines and the frame.. and bingo...:cool

no more rattle...completely gone ..

so happy,

thanks very much for all the help everybody ..this is a great place to find answers to the most perplexing questions..

tony