why oh why no more thump
Thread Starter
Melting Slicks
Joined: Sep 2003
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From: 1,000,000,001 Posts
why oh why no more thump
OK guys this is the 4 time is under a year that I have had to get under my vette and tighten the C-Bar,,,, why?
I have had a thump in the rear end for about a month or two , finally got under it tonight and BANG....... I could turn one bolt by hand,,,, this is the 4th time,,, why..... ALSO, this is the forth time since the tranny has been out and rebuilt
I have had a thump in the rear end for about a month or two , finally got under it tonight and BANG....... I could turn one bolt by hand,,,, this is the 4th time,,, why..... ALSO, this is the forth time since the tranny has been out and rebuilt
Burning Brakes
Joined: May 2000
Posts: 1,160
Likes: 10
From: Nashville TN
Re: why oh why no more thump (SPEED750)
Locktite definitely. Also, you might look at some new bolts. Since a tremendous amount of people are having problems with these(including me), I am thinking they are stretched and need replacement upon removal(torque to yield I think it's called). Some bolts are like this and are meant to only be installed once(like stock head bolts) but they can be reused but end up having problems of backing out.
In the meantime, try adding a little more torque than the factory ratings, like 5-10 more ft.lbs.
In the meantime, try adding a little more torque than the factory ratings, like 5-10 more ft.lbs.
Instructor
Joined: Dec 2003
Posts: 106
Likes: 0
From: McHenry IL
Re: why oh why no more thump (1990CORVETTE)
OK guys this is the 4 time is under a year that I have had to get under my vette and tighten the C-Bar,,,, why?
I have had a thump in the rear end for about a month or two , finally got under it tonight and BANG....... I could turn one bolt by hand,,,, this is the 4th time,,, why..... ALSO, this is the forth time since the tranny has been out and rebuilt
I have had a thump in the rear end for about a month or two , finally got under it tonight and BANG....... I could turn one bolt by hand,,,, this is the 4th time,,, why..... ALSO, this is the forth time since the tranny has been out and rebuilt
Thanks.
Thread Starter
Melting Slicks
Joined: Sep 2003
Posts: 2,775
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From: 1,000,000,001 Posts
Re: why oh why no more thump (SteveBlack90)
It is under you car,, it actually attaches your rear end and your transmission together and your main drive shaft runs inside of it. There are two long bolts that attach it to the rear end, on mine keep coming lose :confused:
It started after I had the tranny rebuilt, hell if I know why/. I tightened them up last night and tore my friggen finger half off doing it :cuss
The car was a piece of poopie for about 5 minutes, then I had another beer and all was good again :D :smiliedrool:
It started after I had the tranny rebuilt, hell if I know why/. I tightened them up last night and tore my friggen finger half off doing it :cuss
The car was a piece of poopie for about 5 minutes, then I had another beer and all was good again :D :smiliedrool:
Safety Car
Joined: Apr 1999
Posts: 4,623
Likes: 2
From: Ohio
Re: why oh why no more thump (SteveBlack90)
Don't feel bad Steve, I've never heard it called a "C bar" before.
1990Corvette, my bet is that the C-channel was never properly aligned. (the rear will pull down, and fowl it) Many of the boneheads that work on these in the field just crank on them with an air gun, and figure that everything will line up. Not so. Either take it back to them so they can get it on the lift and read them the proper proceedure for re-installing it properly. Everything has to be aligned and torqued to spec. NOT just cranked on with a 200 lbs/ft Ingersol Rand air gun!!! On a ZF trans C4, the front only gets torqued to something like 60 lbs/ft if memory serves. Any more, and you can trash the tailshaft bearing. Dunno if it's exactly the same on an auto. Bottom line is don't trust that shop to do it correctly on their own, unless they know more than you do on this one!
1990Corvette, my bet is that the C-channel was never properly aligned. (the rear will pull down, and fowl it) Many of the boneheads that work on these in the field just crank on them with an air gun, and figure that everything will line up. Not so. Either take it back to them so they can get it on the lift and read them the proper proceedure for re-installing it properly. Everything has to be aligned and torqued to spec. NOT just cranked on with a 200 lbs/ft Ingersol Rand air gun!!! On a ZF trans C4, the front only gets torqued to something like 60 lbs/ft if memory serves. Any more, and you can trash the tailshaft bearing. Dunno if it's exactly the same on an auto. Bottom line is don't trust that shop to do it correctly on their own, unless they know more than you do on this one!
Drifting
Joined: Oct 2001
Posts: 1,648
Likes: 1
From: Denham Springs Louisiana
Re: why oh why no more thump (h rocks)
The "thump" that you refer to...does it make the sound whenever you come to a stop? Mine makes some kind of "thump" sound whenever I come yo a stopsign or stoplight after traveling a short or long distance. For instance...it wont make the sound if I am in stop and go traffic, but it will if I go a mile or two and then have to come to a stop....then "thump." Is this how yours sounds? If so...let me know...cause it is getting pretty annoying. GIVE ME THE ANTIDOTE PLEASE! :thumbs:
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Thread Starter
Melting Slicks
Joined: Sep 2003
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From: 1,000,000,001 Posts
Re: why oh why no more thump (h rocks)
[QUOTE] Look up.[/QUOTE} :iagree:
Take the 30 mins, jack the car up and tighten the C-bar,,,, The thump will stop :yesnod: :cheers:
Take the 30 mins, jack the car up and tighten the C-bar,,,, The thump will stop :yesnod: :cheers:
Drifting
Joined: Oct 2001
Posts: 1,648
Likes: 1
From: Denham Springs Louisiana
Re: why oh why no more thump (1990CORVETTE)
OK...antidote received! Could someone now point me in the direction of the "C-BAR" once I get under the Vette. Maybe a pic or two. Thanks! :thumbs:
