[xpoc454]

Since I got my vette last year I noticed that when I am shifting up in the gears I sometimes hear a clunk sound. It happens when I step onm the clutch to shift gears. It doesn't feel like it has anything to do with the transmission.

To me, it sounds like its either coming from the exhaust or underneath the car. I cant really trell though because I am in the car.

I thought maybe it was beacause I was shifting at first that maybe it was kind of a back fire through the side pipes. I have never had a 4 speed with an nearly open exhaust like the one I currently have. I thought maybe it is like what you see when an Indycar is excelerating and the pop a little when going through the gears.

I have also done enough searches on here to see it could also be the snubber bushing. I have a friend coming over tonight and while we were going to fix things, I thought I might try and look at this as a possible culprit.

Does anyone have a description or even better pictures of what I need to look for to determine if this bushing is bad? Before this car, I had never even heard of these before.

thanks
jim

 

[6880 Mike]

...Does anyone have a description or even better pictures of what I need to look for to determine if this bushing is bad?...

The assembly instruction manual has a diagram showing the snubber and the installation.

You'll see it when you crawl under there.

Not the ideal pic, but the snubber mounts in the black bracket on the bottom of the differential. You can see the bolt head right at the X-member.

:thumbsup:

 

[xpoc454]

Thanks, Ill look for it tonight.
Though I had trouble recognizing anything with that picture without all the rust and grease my vette has on it.

 

[gtr1999]

The snuibber is a 2- piece bushing with steel sleeve. Many times it's mushroomed over or dry rotted. Sometimes the pinion seal leak gear oil on it. If you see any cracking,compression, replace it. Don't use poly stick with a quality rubber one. Be sure the new one has the steel sleeve in it.

 

[xpoc454]

Who sells the quality rubber ones, I see a lot of them sell the poly style ones.
What difference make, do the poly ones break down or squeak faster ?

 

[gtr1999]

Some of the poly ones are not the same dimension and will throw off the DS alignment, others don't have the sleeve in them,some are ok. If you need the rubber one I use let me know.

 

[xpoc454]

Some of the poly ones are not the same dimension and will throw off the DS alignment, others don't have the sleeve in them,some are ok. If you need the rubber one I use let me know.

I emailed you, where do i get the rubber ones ?

 

[paul67]

FWIW, here is the difference in size between poly and rubber (poly is on top). Both do have the steel sleeve.

I obtained the rubber version from a non-sponsor here.

 

[gtr1999]

I emailed you, where do i get the rubber ones ?

Sorry, emails have been back logged. I have should have some here I can look if you want.

 

[xpoc454]

I looked at my snubber bushing, or at least what I think is it. It seems to be pretty intact for the sound I am hearing.
Here is the picture I took from the front side of my passenger rear tire.

If this the correct bushing we have been talking about I assume?

 

[iburke]

Don't use poly stick with a quality rubber one. Be sure the new one has the steel sleeve in it.

And why would I not want to use poly???:huh:

 

[gtr1999]

Some of the poly bushings are not the correct size and cause alingment issues.

That is the snubber bushing, it's hard to see if it's dry rotted but doesn't look too bad from what see. I do see what appears to be a pinion seal leak, unless you sprayed something in the area.

 

[iburke]

Some of the poly bushings are not the correct size and cause alingment issues.

That is the snubber bushing, it's hard to see if it's dry rotted but doesn't look too bad from what see. I do see what appears to be a pinion seal leak, unless you sprayed something in the area.

Is there a brand that is making the incorrect size, or are they all the wrong size?

 

[xpoc454]

I didn't spray anything under there. How can I confirm it is a pinion seal leak? What is the fix for it and is there a temprary fix?
It is not leaking enough to leave any marks on my garage.
I only, ask, cause I have so many other things to fix.

 

[gtr1999]

Is there a brand that is making the incorrect size, or are they all the wrong size?

Sorry I don't know that answer. I will not use poly so I haven't had the issue. I have seen some rubber bushings come through without the sleeve. I suspect these are imported parts since a lot of USA mfg has gone the way of .25 gallon, 98 octane gas.

 

[gtr1999]

I didn't spray anything under there. How can I confirm it is a pinion seal leak? What is the fix for it and is there a temprary fix?
It is not leaking enough to leave any marks on my garage.
I only, ask, cause I have so many other things to fix.

If you didn't spray anything there then it's most likely the pinon seal. Although there is a guy here who had a porus casting. Just stick you finger in it and you will know if it's gear oil, thick and smelly.

You can follow my thread here in the tech page , I have one on just this job. It can be done in the car but I like to do them out. I would wash and wipe it down good, check the oil level and watch it to see. The oil will break down the snubber bushing as well so that might be part 2 of the problem you have. Depending on the year and miles you could also have some internal issues with the diff.

 

[xpoc454]

Update on my snubber bushing fix. I ordered it from a vendor and after waiting, for 3 months of delays, I cancled my order and ordered it from WIlcox and got it in 3 days.

Started the process of removing the bushing when I realized that my car may have the original rear shocks on it.

If the shocks are extremely bad, could the rear suspension be moving up and hitting the frame?

I took this picture and notice, that right behind the upper shock mount is what looks to be what is left of some kind of rubber bumper. Both sides are barely recognizeable but they look like rubber stoppers.

Anyone have any idea what this hard to see rubber remnant is called?
Is it the rear trailing arm bumper? as seen here , . . .
http://shop.corvettecentral.com/C2-...uspension/1965-75-Corvette-Rear-p7083589.html


Thanks

 

[Metalkid]

Yeah, that's the part. It prevents the trailing arms from crashing into the frame.

One thing I've read about the difference between the Poly bushings and the rubber bushing is that they may be different dimensions (height) due to the fact that the rubber and the poly compress differently, and once either is installed, the height should be the same. I would also guess that the ones that come without the sleeve assume that you're going to re-use your original sleeve.

However, I just checked out Willcox to see what they had, and found this rather ominous note.

Any comments?

 

[gtr1999]

Yeah, if you're going to beat the heck out of the car, launching it a lot (like my son does) it will break the metal tongue for the snubber. The hole will distort and rip( again my son can do this to a vette) then you'll have to buy a new one and weld it in. For most cars this is not a problem but you can call Tom and get a aluminum puck to solid mount it or just make one up.

 

[Metalkid]

Yeah, if you're going to beat the heck out of the car, launching it a lot (like my son does) it will break the metal tongue for the snubber. The hole will distort and rip( again my son can do this to a vette) then you'll have to buy a new one and weld it in. For most cars this is not a problem but you can call Tom and get a aluminum puck to solid mount it or just make one up.

If you're planning on doing autocross, or road racing would solid aluminum be the way to go, (not planning on drag racing) or would poly still suffice?:huh: