Shifts into reverse with a bang!!!
Thread Starter
Intermediate
Joined: Nov 2004
Posts: 28
Likes: 0
From: LHR UK
Shifts into reverse with a bang!!!
Hi guys,
I have a 75 auto that every time I shift into reverse it goes in with quite a bang, it engages (apart from the noise) and drives okay!
Is this a Trans problem or a propshaft/Diff problem?
Many thanks in advance.
I have a 75 auto that every time I shift into reverse it goes in with quite a bang, it engages (apart from the noise) and drives okay!
Is this a Trans problem or a propshaft/Diff problem?
Many thanks in advance.
Race Director
Joined: Jul 2004
Posts: 12,706
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From: Scottsdale Arizona
Originally Posted by Jims79
don't think it the trany mount but its a cheap & easy fit. the diff mount is also cheap & easy. G/L Could actually be a combination of all three. I've got the first two done and I still get a solid, though reduced clunk. I also get a rattling like noise on cruising or decelerating. Presumably this is the u-joints.
Team Owner
Joined: Aug 2006
Posts: 24,125
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From: Columbia Missouri
Originally Posted by CA-Legal-Vette
Could actually be a combination of all three. I've got the first two done and I still get a solid, though reduced clunk. I also get a rattling like noise on cruising or decelerating. Presumably this is the u-joints.
It's odd. I have bad u-joints and don't get any thump at all.
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Race Director
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From: Wellington, FL
St. Jude Donor '11 thru '25
Out of curiosity, is this a new problem or has it been there for sometime? My experience with a few a C3's is that they can be fairly rough when going into reverse. If you are getting a clanking sound, though, it would point to one of the suggestions above. Just my 2 cents.
Last edited by Jud Chapin; Nov 14, 2006 at 03:16 PM.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by Jud Chapin
Out of curiosity, is this a new problem or has it been there for sometime? My experience with a few a C3's is that they can be fairly rough when going into reverse. If you are getting a clanking sound, though, it would point to one of the suggestions above. Just my 2 cents.
Most all C3 Vettes will squat when put in drive, and sit back up when in reverse...it's just normal of their behavior. When you hear it as well as feel the movement then you have to start checking. If it's a warning sign of u-joints...and you ignore it...you could end up in trouble.
Thread Starter
Intermediate
Joined: Nov 2004
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From: LHR UK
Thanks for the replies, Guys.
I'll try and give it a through check over as it's off road for the winter, and try and do all of the above, I know the Diff seal needs to be done as well, is there anything else that could do with renewing while I'm at it, gearbox seal? Nice to have all the parts to hand especially being in the UK!!
I'll try and give it a through check over as it's off road for the winter, and try and do all of the above, I know the Diff seal needs to be done as well, is there anything else that could do with renewing while I'm at it, gearbox seal? Nice to have all the parts to hand especially being in the UK!!
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Just a thought; How high is your idle? When your idle is a little too high it will make the shift to Reverse or Drive a little rough. If it's where it's supposed to be the other posters are on the right track.
Team Owner
Joined: Aug 2006
Posts: 24,125
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From: Columbia Missouri
Originally Posted by capevettes
Just a thought; How high is your idle? When your idle is a little too high it will make the shift to Reverse or Drive a little rough. If it's where it's supposed to be the other posters are on the right track.
That's a good call. With an idle close to 1000 or better you'll have a lot of 'Oomph' getting through the drive train.
Racer
Joined: Oct 2006
Posts: 318
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From: Cape Coral FL
im in the same boat as you mine like drops and bangs the whole car when shifting from R N 3 2 1 all of em it fells like the car drops down when i shift it to 3rd is it something i should worry about?
Team Owner
Joined: Aug 2006
Posts: 24,125
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From: Columbia Missouri
Originally Posted by whoodiestyle
im in the same boat as you mine like drops and bangs the whole car when shifting from R N 3 2 1 all of em it fells like the car drops down when i shift it to 3rd is it something i should worry about?
If it 'CLANKS' then yes...if not...don't worry, and check your idle.
Intermediate
Joined: Oct 2006
Posts: 38
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From: Bel Air MD
Just to add to the general comments...I completed a partial overhaul of my 70, to include rebuilt engine, rebuilt TH400, new U-Joints, new bushings throughout the drive train, and I still get the same clunk I used to get prior to the rebuild. I must say though that my idle is set higher, and that I did not have the rear rebuilt.
I will reduce the idle speed since I believe that it will make a big difference.
....
I will reduce the idle speed since I believe that it will make a big difference.
....
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by Corvetteran
Just to add to the general comments...I completed a partial overhaul of my 70, to include rebuilt engine, rebuilt TH400, new U-Joints, new bushings throughout the drive train, and I still get the same clunk I used to get prior to the rebuild. I must say though that my idle is set higher, and that I did not have the rear rebuilt.
I will reduce the idle speed since I believe that it will make a big difference.
....
I will reduce the idle speed since I believe that it will make a big difference.
....
What is your idle speed right now? Is there a specific reason why it's high like that or it's just a case where you haven't lowered it in a while?
