61 Wheel Bearings

[Jack H.]

Check integrity of insulation/wiring on starter/solenoid.

If no obvious problems, disconnect battery and start ohming branch runs per wiring diagram one leg at a time. Key here is short appears to be in unswitched (via ignition) branch of circuitry and that would include engine compartment B+ buss (side of horn relay), the starter supply line, interior lamps, Etc.

[Alan Bishop #34929]

61 Wheel Bearings

I have pulled the axles out of my 61. The bearings are both "HYATT 1542-WA" Could they be original?

Thank You

[Bill Clupper]

Re: 61 Wheel Bearings

could be, New Departure/Hyatt was a division of GM at that time

[Dale Pearman]

YOU BETCHA

They ARE original roller bearings and your car has a positraction rear end. Roller rear bearings started appearing on Corvettes in 1958 and ran through 1962 (when Corvette production ceased) for positraction rear ends only. The open rear ends used ball bearings. These puppies are 0.900 inches thick and use a spacer washer 0.100 inches thick between the bearing and the bottom of the bearing well. They have one rubber dust seal around the outside circumference and an oil seal on the outboard side of the bearing only and oriented so as to stop oil flow from the differential, through the bearing and onto the brake shoes. The inboard side is open to receive posi lubricant from the differential.

These bearings are scarce and expensive. Most people use the Delco replacement bearing which was originally designed for use in a machine lathe.

This replacement bearing is available from C Central or any of the other suppliers. BEWARE! The replacement is 1.000 inches thick such that the spacer washers are not used. (send me your unwanted washers). There are two rubber dust seals around the circumference of the bearing. The bearing is a ball type. It has a dust seal for shipping only that resembles a large washer and is colored either black or greenish plastic. 9 out of 10 machinists who will press these bearings onto an axle will think that this plastic is an oil seal and install the bearing backwards.

There is a legitimate oil seal installed on the bearing in such a way as to prevent any lubrication from ever reaching the bearing. What happens over and over is that the machinist installs the bearing backwards and it runs until the packing grease heats and disappears. Next the bearing gets hot and destroys the oil seal allowing oil into the bearing. This oil bypasses the green washer-like dust cover and drips down onto the brake shoes. New bearings are installed the same way and it's the same problem all over again.

In order to use the (RB307? or whatever replacement) ball bearing, remove the greenish or black washer-like dust shield and discard it. Remove the oil seal carefully and reverse it's installation physically so as to block oil flow from the opposite direction. Or else install a new oil seal. (NAPA item). Now you've got a ball bearing that you can install with the inboard side allowing oil into the bearing and the outboard side preventing oil from coming out of the bearing.

You would think Delco would include instructions or C Central would warn folks about the fact that an RB 307 can't be used as shipped from the supplier!

Dale.

[Alan Bishop #34929]

Re: YOU BETCHA

The spacers are there, one came out with the axle, the other has a snug fit. I plan on cleaning up the bearings and re using them. I can go back to 1972 with past owners..... this car has MAX 10,000 miles use in 29 years, do you think the rubber seal will hold? (they are not leaking now)

One more thing, the Brake Backing Plates, I would like to take them off and clean them up...... any ideas, I do not want to ruin them!

Thank You

[Dale Pearman]

If It Ain't Broke Don't Fix It

Clean your bearings and pack with ROLLER bearing grease. (not ball bearing). If the seals don't leak then don't replace them.

Clean the backing plates while on the car unless you enjoy making extra work for yourself and risking damage to components.

Best of luck and fun,

Dale.

[Alan Bishop #34929]

Plate are Big Brake

I really need to take the rear covers off of the backing plates to restore them correctly. Also of the "8" rear screen covers I am missing one, and the screen it covered needs repair.

I am close to positive that these are original brakes and never been off.

I do not think the plates are heavy enough for much force, or hammering.

HELP ... IDEAS!!

[Loren L.]

Re: Plate are Big Brake

Be careful, Allan, because Dale's about to offer to trade some backing plates WITHOUT holesto you so you won't have to be bothered with the repair....as a matter of factm if you make that deal, he might even come to Michigan and do the swap for you!!!

[Dale Pearman]

Loren You're A Seer

A mystic! You read my mind completely. Which one of us will get there first?

The big brake option presents another set of considerations. The BACKING PLATE COVERS are thin and expensive ($3,000.00 for a set of covers IF you can find them and that's without the backing plates). You should remove each backing plate for cleaning. The bolts holding the covers will be frozen. DO NOT shear them trying to take them out. Use a torch to get the bolts (cap screws) cherry red and stick a candle on them such that the candle wax will permeate the threads. That usually works. Hire a good machinist if necessary. Saving the covers is the number 1 priority!

Dale.

[Alan Bishop #34929]

REPAIRS

The left front rear screen had no rear cover. The screen is still there but needs some repair, any ideas? This cover must have been torn off as the screws are still in the brake plate. (this is were I will start with your candle test) The rest of the screens look perfect.

PS. I NEED ONE COVER!

[Loren L.]

Re: REPAIRS

Chevrolet Technical Service Bulletin #812 dated June 8, 1962 dealt with 687 Brake Equipment needing "additional cooling" when usage was "unusually severe" & advised replacing the 1/8" mesh with 1/4" mesh; further instructions referred to the mesh as "galvanized" and to "Braze or Solder" to the inside of the brake flange plate. Hope this helps with the repair - lotsa luck with the missing cover, but maybe the missing owners have it .....

[Alan Bishop #34929]

GALVANIZED

Is the key word, why the screens are not rotted out after 40 years.

[Alan Bishop #34929]

Re: GALVANIZED

I have the plates off the car. As I clean up the Brake Plates I have noticed were the paint is missing that the Plates are a Non Rusty Gray ... they look Galvanized themselves, are they?