Tod

When driving the 65' and the road curves to the left, I hear a squeeling noise in the rear of the car. After the road straightens out, the noise usually stops shortly after. Right curves or turns don't seem to bad with the noise. I first thought it was the universals, but they usually emit a "clunking" sound. Maybe its the wheel bearings? I never had any experience with those. Any thoughts? I will not attempt a wheel bearing job myself, so how much is "reasonable" for competent work?

Thanks
Tod

Joys

What you hear is probably the right rear brake disc touching either backing-plate or pads due to a loose wheel bearing. Rear wheel bearings on old corvettes are often overlooked due to the somewhat heavy work involved in servicing these bearings. Nevertheless, you really need to know the state of both left&right rear bearings on your car.
Good luck!

Plasticman

Rear wheel bearing failure will go through several phases of failure. They are a known weak point in the C2/C3 Vettes, and were so the entire length of the first generation IRS model run.

The first phase is the slight squeak that we sometimes hear when running along a sound reflective wall (concrete center dividers will reflect this sound) or next to a car that is pacing the Vette. We often go into denial at this point. Best to get it looked at now, and maybe save yourself from having to buy a new spindle, etc.

The next phase is where the squeak becomes louder and more consistent. Now it has caught your attention, you know something is wrong (but maybe it will fix itself - so you say to yourself). At this point the bearing probably has damaged the spindle, but may still be saved.

The next phase is where the squeak is even louder (more like a shriek) and there is also a grinding noise, and sometimes a clunk and BANG accompanies the squeak (as though something is getting chewed up occasionally - and it is!). Rarely is this ignored! Forget the spindle - it is history!

The last phase is where the bearing can no longer be considered a "bearing", but just a mass of semi frozen together parts that are groundup and melted together. You are lucky that anything will even rotate, and the wheel probably shows a severe negative camber. If it does rotate, it may rotate only in one direrection, and if you try to go in the opposite direction, a severe binding follows (as though you are trying to drive over a fire hydrant) until it breaks free.

And yes, I have driven a 66 Vette through all of these phases (but it did get me home after a 1540 mile long weekend trip!). Also drove my 70 Vette approx. 250K miles, with only replacing each set (side) of bearings once, but repacking and readjusting them at 100K mile intervals. There are a couple of "secrets" to doing that, since normal rear bearing life is about 60-65K miles. And GM did not make these bearings easily adjustable or repackable.

Good luck,
Plasticman

Vette-66

Is there a good method to re-pack/check these or is dooms-ville the next town?

Thanks
Chuck

Plasticman

Chuck,

John Greenwood told me many years ago the method he used on his race Vettes. But I have mentioned it on the forum previously, and was told it was wrong, bad, terrible, stupid - you get the picture.

But I will mention it, and we will see if the same condemnation occurs.

A little history first. The original drum brake design of the IRS did not provide any retension of the rear wheel assembly if the rear spindle was damaged and broke. Now I have never seen one break, but anything "can" happen (and I would expect that if anyone should be concerned about it, it would be a racer like John). When the disc brakes arrived in 65, the caliper (capturing the rotor) now provide that retension feature (to a degree). However, the spindle design did not change, since (as I was informed) the factory wanted a positive method of retension. They felt that if the spindle was to break, it would be at the end of the U-joint inner splined area, since that is the thinnest cross sectional area of the spindle. Now as we know, the spindle bearings are a press fit to the spindle. That was the supposed purpose of the press fit - spindle retension. I think it was more of: "That is the way it is designed, and we know how to assemble it that way, and we have bigger issues to be worried about, and besides it provides some business for our dealers".

Note that the original bearing spec is .001" to .008" end play. Now if you are on the assembly line and the assembly falls anywhere within that range, out the door it goes. However, I would not want to receive any vehicle with a bearing end play towards the wide end of that spec!

John told me that all of his race Vettes used "slip fit" spindle bearings. He would take off material from the spindle for the bearings to slide on (and off obviously). This is the same type construction as on the front wheel bearings, and made complete sense to me. He also told me to set the end play to the minimum .001" end play (also made sense). Since the bearing assembly can now be assembled, measured, and then disassembled and readjusted as needed, it was easy to obtain the optimum end play setting. The last item was to use the best grease possible. At the time, I used Amsoil synthetic grease. I would not hesitate to recommend it, based upon my results. Note that I chucked my spindles up in my lathe to remove the material needed to make the bearings "slip fits". I am sure this can be done at any competant machine shop for a minimal fee, since it is really easy to do.

I can also say that at no time during any of my 100K inspections and readjustments did I see any sign of bearing or grease failure, or any real need to readjust the bearings. But it was too easy to do (other than undoing the U-joint and suspension mount), and gave me peace of mind.

Let the flames begin anew!

Plasticman

LB66383

No flames. Makes perfect sense to me.

6coupe4

I had a similar noise and changed the bearings, still had noise. Someone told me to change the rear fluid and add the POSI additive and the noise went away. If you haven't changed the oil lately, it's a quick and cheap thing to try.

GO GIRL

I had exactly the same problem on my 64 and also thought it was the bearings. Turned out to be the outer u-joint. They squeak before they clunk.

Trophy Blue

Plasticman, would a bad bearing cause a vibration that I feel in my seat while driving over forty miles per hour??

Tod

How does one go about checking if a u-joint is bad?

GO GIRL

If it has a zerk fitting, grease it. If not, replace it. A $10 u-joint is alot cheaper than replacing bearings. Give it a try.

Plasticman

From what I have seen a bad bearing would really be making a lot of noise before any vibration would be felt. Vibration sounds like a U-Joint (or wheel/tire balance) issue.

Plasticman

ghostrider20

Is the noise like a squealing tire? Or a groan from within? Bearing noises make a high pitch squeal to start then a groan and then grinding/scrapping noise.

The rear end will make a groan, with clunk noises. Posi lube and a fluid change is where I would start. This will be ever so noticeable making a sharp turn at parking lot speeds.

Bad u-joints make a clunk when the load is changed from power on, to power off, or in a car with an automatic trans, step on the brake, and shift from reverse to a forward gear, and you will hear them clunk.

You can look at the u-joint caps and see if they are rotating in the pressed in bores. A rotating cap will have a shinny spot where the keeper rings are riding.

Have you had the rear aligned lately? What is the toe set at. If the one side is toed out to much, and you turn the opposite direction from that wheel you may get tire squeal ever so slightly??

Mark

Joys

about twenty years ago I had a C3, doing a gentle u-turn one spindle broke right off inside the u-joint. From a reputable corvette shop in Santa Ana,Ca. I was also told to bring the new spindle to a machine shop and have them turn the spindle down from press-fit to slip-fit. This is really a delicate operation for a novice, ever so slightly under perfect and the bearing will be too loose. It turned out OK and setting the play became a breeze. I sure would do it again on my -66. I'm sure more than 50% of all C2/C3's out there is in need of a rear wheel bearing service....Why not do it today? I can guarantee you will have a much better feeling next time you drive precious!