Rear end issues
Thread Starter
Racer
Joined: Jul 2000
Posts: 416
Likes: 4
From: Iron Mountain,Michigan
Rear end issues
Fellow Vetteheads,
For the last few years, I have had a banging noise in the rear when I let off the gas.
I don't drive the vette that much so I have been babying it, however, I have to deal with
this before something breaks. Last year I brought it to a garage to check out the U-joints
and they said they looked OK. I have heard about lash in the rear differential, but know
nothing about it. Searching for answers as to what else I should have checked out, can
anyone lead me to some possible remedies for this?
Thank You
For the last few years, I have had a banging noise in the rear when I let off the gas.
I don't drive the vette that much so I have been babying it, however, I have to deal with
this before something breaks. Last year I brought it to a garage to check out the U-joints
and they said they looked OK. I have heard about lash in the rear differential, but know
nothing about it. Searching for answers as to what else I should have checked out, can
anyone lead me to some possible remedies for this?
Thank You
Le Mans Master
Joined: May 2007
Posts: 5,028
Likes: 1,120
From: North tonawanda NY
Fellow Vetteheads,
For the last few years, I have had a banging noise in the rear when I let off the gas.
I don't drive the vette that much so I have been babying it, however, I have to deal with
this before something breaks. Last year I brought it to a garage to check out the U-joints
and they said they looked OK. I have heard about lash in the rear differential, but know
nothing about it. Searching for answers as to what else I should have checked out, can
anyone lead me to some possible remedies for this?
Thank You
For the last few years, I have had a banging noise in the rear when I let off the gas.
I don't drive the vette that much so I have been babying it, however, I have to deal with
this before something breaks. Last year I brought it to a garage to check out the U-joints
and they said they looked OK. I have heard about lash in the rear differential, but know
nothing about it. Searching for answers as to what else I should have checked out, can
anyone lead me to some possible remedies for this?
Thank You
Race Director
Joined: Nov 2006
Posts: 13,232
Likes: 7,826
From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
2022 C3 of the Year Finalist - Modified
Cruise-In VIII Veteran
Broken snubber bushing at the front diff mount??
Thread Starter
Racer
Joined: Jul 2000
Posts: 416
Likes: 4
From: Iron Mountain,Michigan
Not familiar with snubber bushing? Where is it located, what does it look like.
Something I could do myself? Not a mechanic but am somewhat mechanically inclined.
Thank Both of you for your HELP.
Something I could do myself? Not a mechanic but am somewhat mechanically inclined.
Thank Both of you for your HELP.
Melting Slicks
Joined: Nov 2006
Posts: 3,411
Likes: 1,821
From: Apple Valley, MN
Fairly easy to replace but you’ll need a pry bar to push the differential down to create a gap large enough to install the new (taller) bushing. Best to do with the car on a lift.
Intermediate
Joined: Jul 2011
Posts: 39
Likes: 5
From: Cleveland, OH
What year? Do the loud clunks accompany some faint bumps and hesitation? Most likely experienced in slow gradual turns at slow speed?
I'm not sure this is what you are experiencing, but this is what I found with my '79...
In late model C3s, the tempering and hardening of the two axles was poor. They simply were not designed to last 40+ years.
As a result, the ends that mesh with the differential wear, revealing softer metal - which wears even faster. When they wear, they get shorter and that introduces play - which presses against the differential in gradual turns). My clunking progressed to the point I heard/felt it even while driving straight ahead. Eventually, they wear to the point of breaking, causing considerable damage to the rear end and possibly the vehicle if it completely destroys the differential while driving.
My friend and Corvette guru (Corvette shop owner for 50+ years) shared with me that virtually ALL of the late model C3s he works on eventually needed to have the axles replaced. I believe him, too, as he had quite a collection of worn and broken axles. He replaced mine with new properly-hardened axles along with a differential rebuild, and the car is better than new.
I'm not sure this is what you are experiencing, but this is what I found with my '79...
In late model C3s, the tempering and hardening of the two axles was poor. They simply were not designed to last 40+ years.
As a result, the ends that mesh with the differential wear, revealing softer metal - which wears even faster. When they wear, they get shorter and that introduces play - which presses against the differential in gradual turns). My clunking progressed to the point I heard/felt it even while driving straight ahead. Eventually, they wear to the point of breaking, causing considerable damage to the rear end and possibly the vehicle if it completely destroys the differential while driving.
My friend and Corvette guru (Corvette shop owner for 50+ years) shared with me that virtually ALL of the late model C3s he works on eventually needed to have the axles replaced. I believe him, too, as he had quite a collection of worn and broken axles. He replaced mine with new properly-hardened axles along with a differential rebuild, and the car is better than new.
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Thread Starter
Racer
Joined: Jul 2000
Posts: 416
Likes: 4
From: Iron Mountain,Michigan
Going to take the car out on the road in a couple days
just took out of storage drove it home and parked. Will
pay more attention. I have no issues with turning, only when
I let off the gas sharply do I get that klunk. Will need to jack up
and take a good look at all these possible issue areas.
THANK ALL for your input.
just took out of storage drove it home and parked. Will
pay more attention. I have no issues with turning, only when
I let off the gas sharply do I get that klunk. Will need to jack up
and take a good look at all these possible issue areas.
THANK ALL for your input.
or tranny mounts/ engine mounts...
Le Mans Master
Joined: Aug 2006
Posts: 7,426
Likes: 1,559
From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
Thread Starter
Racer
Joined: Jul 2000
Posts: 416
Likes: 4
From: Iron Mountain,Michigan
Thank You so much, I did find it, and it was rubber and in good shape and tight
tried the pry bar and it was solid, no cracks etc. Will bring to garage next week
and check out U-joints, and look at other bushings you all described. Also don't
know what to do about checking rear axles or if they can be checked?
Thank All of You again.
tried the pry bar and it was solid, no cracks etc. Will bring to garage next week
and check out U-joints, and look at other bushings you all described. Also don't
know what to do about checking rear axles or if they can be checked?
Thank All of You again.
Tech Contributor
Joined: Aug 1999
Posts: 15,175
Likes: 3,987
From: Connecticut, USA
Rear axles can be checked in the car. Check for the endplay in them by pushing in, them measure pulling out.
For original diff's
010-025" is ok
025-040" more going on but still useable
over 040" needs attention.
For rebuilt diff's
They all should be 005-010 max- above that is poorly done,
For original diff's
010-025" is ok
025-040" more going on but still useable
over 040" needs attention.
For rebuilt diff's
They all should be 005-010 max- above that is poorly done,
Thread Starter
Racer
Joined: Jul 2000
Posts: 416
Likes: 4
From: Iron Mountain,Michigan
I guess my inspection of the snubber bushing was a bust. Brought it to a shop
to have a REAL mechanic inspection......he checked out what he could find externally
and could not find anything out of the ordinary, however, he did find that the snubber bushing
was shot, embarrassing!!! He did try to make me feel somewhat better by saying that it would
look OK from the bottom but that it was shot when looking at it from above on a hoist and trying
to see from below would be hard. $200.00 for inspection and snubber replacement, worth it for
peace of mind that it wasn't anything more critical. Once again Thank all of you for the assistance.
to have a REAL mechanic inspection......he checked out what he could find externally
and could not find anything out of the ordinary, however, he did find that the snubber bushing
was shot, embarrassing!!! He did try to make me feel somewhat better by saying that it would
look OK from the bottom but that it was shot when looking at it from above on a hoist and trying
to see from below would be hard. $200.00 for inspection and snubber replacement, worth it for
peace of mind that it wasn't anything more critical. Once again Thank all of you for the assistance.
Thread Starter
Racer
Joined: Jul 2000
Posts: 416
Likes: 4
From: Iron Mountain,Michigan
My apologies for taking so long to get back to you, I just wanted to
find the right people to bring the vette to. As always Thank all of you
will be seeing you for more of your expertise in the future.
find the right people to bring the vette to. As always Thank all of you
will be seeing you for more of your expertise in the future.