C2 rattle (clunk) in rear end

anychevy · April 13, 2012, 12:34:01 PM

Thought this was just a loose spare carrier (it's not)
Pulled the wheels off, took the weight off the control arms and noticed I could pull the half shaft yokes out of the diff
~1/2" on the LHS and ~1/4" on the RHS ?
I read over on CF this amount of end play is not normal, but also not dangerous (not going to fall out)
Could this rattle (clunking) noise be the yoke slamming back into the diff over bumps ?
Anyone have any experience with this ?

bfit · April 13, 2012, 12:50:20 PM

I had a noise in the rear of a 70 model recently
and looking into the problem I came up with some specs
that end play the i found for the yoke
was listed at no more than 1mm (0.040" )
but I also found 0.3mm (0.012" )

I have one car that has 3/16" and has no noises at all.
Bfit

anychevy · April 13, 2012, 01:09:15 PM

With the wheels on the ground and the jack under the leaf, one side at a time.
I can rock the LHS wheel and move the yoke in and out of the diff around 1/2"
The RHS has no noticeable end play when I do the same thing.
So I'm thinking the C clip (or whatever type of retainer is used) is broken or worn out.
Or the trailing arm bushes are gone, or both ?

bfit · April 13, 2012, 01:38:21 PM

Dave I have not pulled the diff apart in a vette yet
Buy if you take the half shaft out of the LHS and the clip is gone or broken
I would think you could pull the yoke out

May be some one who has had a Diff apart could confirm if that is true

If the diff has to come out I can see that is not a small job
Bfit

anychevy · April 13, 2012, 02:11:54 PM

Quote from: Bfit link=topic=9139.msg1045942464#msg1045942464May be some one who has had a Diff apart could confirm if that is true
If the diff has to come out I can see that is not a small job
Bfit

It looks like you can get to the guts with most of the housing still in.
Still a fairly big job that I don't have the tools for.
I'll have to get it towed, can anyone recommend a place in Sydney ? :shake:

72vet · April 13, 2012, 02:27:28 PM

Hi Dave, I've moved your thread for ya.

Give John a call 9831 6072 - Jmac Diff & Gear - Arndell Park

Nick

anychevy · April 13, 2012, 02:41:14 PM

Quote from: 72vet link=topic=9139.msg1045942467#msg1045942467Hi Dave, I've moved your thread for ya.

Give John a call 9831 6072 - Jmac Diff & Gear - Arndell Park

Nick

Thanks Nick
I gave him a call and he said that amount of end play is not good, but there could be other issues.
What else under there, makes a dull rattle and sounds like something hitting the body, but only over bumps ?
The car seems to drive fine, no bearing noises, just this annoying rattle

72vet · April 14, 2012, 09:24:48 AM

Have you looked at the front Diff mount?

http://www.ecklerscorvette.com/corvette-differential-bracket-mounting-kit-front-1963-1982.html

anychevy · April 14, 2012, 10:16:47 AM

Quote from: 72vet link=topic=9139.msg1045942475#msg1045942475Have you looked at the front Diff mount?

It's old, but still looks pretty thick and tight.
I broke one on a 68 years ago and it made a hell of a noise as soon as you let the clutch out, almost like the ring gear lost a tooth.

This is more of a dull rattle, only over bumps and sounds like something's loose ?
I think it's possibly the side yoke retaining clip (or clips) I can pull the yoke out of the diff 1/2" :banner:
I believe the little clip at the end of the spline is all that holds them in ?

sirfixalot · April 14, 2012, 05:01:54 PM

Maybee exhaust where it comes under diff my 78 has a sheet metal heatshield there which I have never got round to fitting after replacing diff.
Handbrake cable on exhaust pipe?

Camo · April 14, 2012, 07:24:26 PM

Quote from: anychevy link=topic=9139.msg1045942479#msg1045942479............I think it's possibly the side yoke retaining clip (or clips) I can pull the yoke out of the diff 1/2" :banner:
I believe the little clip at the end of the spline is all that holds them in ?

I had those clips broken on my 77 and had all that free play you speak of, but had no noise that you speak of. You will need to get that fixed though. If it's been rubbing badly inside the diff you will need new yokes.

Have you checked bumper bar brackets etc?

anychevy · April 15, 2012, 09:45:20 AM

Quote from: Admin link=topic=9139.msg1045942489#msg1045942489If it's been rubbing badly inside the diff you will need new yokes.
Have you checked bumper bar brackets etc?

Checked all the usual suspects, bumpers, exhaust (side pipes) spare carrier etc. etc.
All the rear suspension bushes look flogged out, so one or more could be the culprit, but will also pull the diff out and get it looked at,.
The yoke moving around is definately not good.
Anyone know a good source for a rear suspension rebuild kit ?
I might as well do the lot while I have it in bits :rolleyes:

72vet · April 15, 2012, 10:36:03 AM

Try these guys, http://www.vbandp.com/

While you're at it you might as well replace the wheel bearings, and the handbrake mechanism.

anychevy · April 16, 2012, 04:12:00 PM

Quote from: 72vet link=topic=9139.msg1045942492#msg1045942492While you're at it you might as well replace the wheel bearings, and the handbrake mechanism.

Yep, I might as well.
Thanks

gtc · April 16, 2012, 08:55:55 PM

Do the handbrakes on C2s actually work?

(They're little more than a joke on C3s)

anychevy · April 17, 2012, 02:17:16 PM

Quote from: gtc link=topic=9139.msg1045942508#msg1045942508Do the handbrakes on C2s actually work?

They are basically the same, o.k. for parking, but I wouldn't trust it on a steep hill.