'79 Vette, binding/clicking/rubbing?
Thread Starter
Racer
Joined: Jul 2002
Posts: 322
Likes: 0
From: Wainwright Alberta
'79 Vette, binding/clicking/rubbing?
Hey, I just picked up my first corvette tonight. It's a '79 350 auto L48.
After I drove it 200kms home I noticed then when I put it into gear and drive forward or reverse, it sounds like something in the back is rubbing up against the tires. It just does it until I get going. I couldn't figure out what it was, though I'm not much of a car person.
Any ideas? Is this serious?
Le Mans Master
Joined: Feb 2001
Posts: 7,226
Likes: 399
From: Northern CA
Re: '79 Vette, binding/clicking/rubbing? (SicChild)
Sounds like your posi-clutches need to be lubricated. Don't worry, it's very common and easy to fix. Either take it to a shop or do it yourself. The rear-end fluid needs to be pumped out and a bottle of the GM differential additive needs to be added in with new fluid. No sweat. Good Luck! :cool:
Melting Slicks
Joined: Sep 2001
Posts: 2,826
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From: Why Drive When you can ride
Re: '79 Vette, binding/clicking/rubbing? (SicChild)
...I added two bottles of the posi lube stuff. It cost about $8.00 CDN per bottle. Just take your car to a lube shop, i.e. Mr. Lube, cost about $20 for them to do it. Well worth it, considering how much trouble it is to pump out the old fluid.
Good luck
:cheers:
Good luck
:cheers:
Drifting
Joined: Mar 2001
Posts: 1,411
Likes: 2
From: St. Louis, Missouri
Re: '79 Vette, binding/clicking/rubbing? (SicChild)
Based on your description, I'm not convinced that positraction clutches are your problem. Nonetheless, it wouldn't hurt to change out your differential fluid anyway.
Unless you have a lift, it would probably be easier to remove the spare tire cover to gain access to the differential drain plug (being a newly purchased car you'll want to check the condition and pressure of your spare anyway).
Buy a cheap hand pump and siphon out the old stuff. If it is the original 23-year-old fluid, it will smell like it came from the bowels of hell. Add about 8 ounces of positraction fluid and fill to the specified level with gear oil. Put everything back together and go.
Unless you have a lift, it would probably be easier to remove the spare tire cover to gain access to the differential drain plug (being a newly purchased car you'll want to check the condition and pressure of your spare anyway).
Buy a cheap hand pump and siphon out the old stuff. If it is the original 23-year-old fluid, it will smell like it came from the bowels of hell. Add about 8 ounces of positraction fluid and fill to the specified level with gear oil. Put everything back together and go.
Thread Starter
Racer
Joined: Jul 2002
Posts: 322
Likes: 0
From: Wainwright Alberta
Re: '79 Vette, binding/clicking/rubbing? (Neo Fender)
Based on your description, I'm not convinced that positraction clutches are your problem.
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Drifting
Joined: Mar 2001
Posts: 1,411
Likes: 2
From: St. Louis, Missouri
Re: '79 Vette, binding/clicking/rubbing? (SicChild)
When the clutches were grabbing on my car, the tires would squeal (very easily) during left hand turns. A rubbing sound could be a tire rubbing (should be easy to check for visually) or warped brake rotors.
Thread Starter
Racer
Joined: Jul 2002
Posts: 322
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From: Wainwright Alberta
Re: '79 Vette, binding/clicking/rubbing? (Neo Fender)
Yeah, I got someone to lay underneath while I did it. We couldn't find anything rubbing at all. It only happens when you first put it into gear and release the break. After that it's fine until you stop and go again.
Melting Slicks
Joined: Nov 2000
Posts: 2,507
Likes: 114
From: St. Louis Mo
Re: '79 Vette, binding/clicking/rubbing? (SicChild)
SisChild
Believe it or not it could be the tires themselves. When I first got my 79 I had 255s on them and found them to rub, with the same symtoms your indicating. Could be your problem, or not..LT :rolleyes:
Believe it or not it could be the tires themselves. When I first got my 79 I had 255s on them and found them to rub, with the same symtoms your indicating. Could be your problem, or not..LT :rolleyes:
Melting Slicks
Joined: May 2002
Posts: 2,431
Likes: 52
From: Florida
Re: '79 Vette, binding/clicking/rubbing? (Neo Fender)
Make sure tire dia. is the same on each rear tire also. The additive usually fixes this and twice the amount factory recommends will cure the grippyness of the steel plates. Never run dissimilar tire sizes on a clutch or locking type diff. ~ in my opinion.
Good luck and let us know what it was.
:seeya
Good luck and let us know what it was.
:seeya
Burning Brakes
Joined: Sep 2001
Posts: 1,166
Likes: 0
From: Tulsa Ok
Re: '79 Vette, binding/clicking/rubbing? (SicChild)
[QUOTE]
It only happens when you first put it into gear and release the break. QUOTE]
Sounds like an E-brake issue to me. The parts corrode over time and bind allowing the shoes to not retract sufficiently causing a rubbing sound.Replace with stainless and never have the problem again.
:cheers:
It only happens when you first put it into gear and release the break. QUOTE]
Sounds like an E-brake issue to me. The parts corrode over time and bind allowing the shoes to not retract sufficiently causing a rubbing sound.Replace with stainless and never have the problem again.
:cheers:
Thread Starter
Racer
Joined: Jul 2002
Posts: 322
Likes: 0
From: Wainwright Alberta
Re: '79 Vette, binding/clicking/rubbing? (FeedVaal)
I never used the e-break yet =\ Let me sum everything up:
- First got the car, I didn't hear it.
- Halfway home (about 100kms later) heard it a little, not bad though
- Finally got home, and it was pretty noticeable.
- Seems to be worse when the car is hot
- Happens when I put it into gear and release the break pedal
- Happens when I go straight too (not just when turning)
- tires are the same size
- looked underneath to see anything rubbing but didn't see anything
there, I think that's everything summed up :)
- First got the car, I didn't hear it.
- Halfway home (about 100kms later) heard it a little, not bad though
- Finally got home, and it was pretty noticeable.
- Seems to be worse when the car is hot
- Happens when I put it into gear and release the break pedal
- Happens when I go straight too (not just when turning)
- tires are the same size
- looked underneath to see anything rubbing but didn't see anything
there, I think that's everything summed up :)
Le Mans Master
Joined: Jun 2002
Posts: 8,339
Likes: 24
From: I can walk to MA
Re: '79 Vette, binding/clicking/rubbing? (SicChild)
Could be:
sticky u-joint at the beginning of it's end
bad rear caliper making brakes rub - should stop when going straight and braking
worn differential yokes rubbing seals/side of differential
did I say ujoint ? well I said it again
(hopefully not) rear wheel bearings need grease/replacement
This is a partial list of probable things to check.
Let us know how it turns out and the fix. Good luck.
BTW - that's one brave soul that would lay under there as you put it
in gear and let off the brake !!
:seeya
[Modified by Daves_rusty_75, 2:25 PM 7/26/2002]
sticky u-joint at the beginning of it's end
bad rear caliper making brakes rub - should stop when going straight and braking
worn differential yokes rubbing seals/side of differential
did I say ujoint ? well I said it again
(hopefully not) rear wheel bearings need grease/replacement
This is a partial list of probable things to check.
Let us know how it turns out and the fix. Good luck.
BTW - that's one brave soul that would lay under there as you put it
in gear and let off the brake !!
:seeya
[Modified by Daves_rusty_75, 2:25 PM 7/26/2002]
Thread Starter
Racer
Joined: Jul 2002
Posts: 322
Likes: 0
From: Wainwright Alberta
Re: '79 Vette, binding/clicking/rubbing? (Daves_rusty_75)
BTW - that's one brave soul that would lay under there as you put it
in gear and let off the brake !!
in gear and let off the brake !!