Need help with C2 front wheel bearings
03-25-2012, 10:29 AM
#21
Race Director
Member Since: Nov 2000
Location: Beverly Hills (Pine Ridge) Florida
Posts: 10,170
Received 529 Likes
on
379 Posts
Brian,
I am doing this now myself on the 435 car. I have an extra set of bearings (USA Timken) if you need them.
The issue most fail to address with the front brakes on these cars is lateral runout after front rotors are replaced. The original hub/rotor was machined on the bearing axis after the hub and rotor were riveted together. Typically the surface of the hub where the rotor mounts is so far out of square to the axis of rotation that a significant lateral runout condition results and that is what will cause a softening pedal over time.
The only solutions are to either shim the rotor to achieve less than 0.004" lateral as measured with the bearing preloaded (no end play) a a point one inch inboard of the rotor OD, or to machine the rotor as an assembly (less reliable).
Nick
I am doing this now myself on the 435 car. I have an extra set of bearings (USA Timken) if you need them.
The issue most fail to address with the front brakes on these cars is lateral runout after front rotors are replaced. The original hub/rotor was machined on the bearing axis after the hub and rotor were riveted together. Typically the surface of the hub where the rotor mounts is so far out of square to the axis of rotation that a significant lateral runout condition results and that is what will cause a softening pedal over time.
The only solutions are to either shim the rotor to achieve less than 0.004" lateral as measured with the bearing preloaded (no end play) a a point one inch inboard of the rotor OD, or to machine the rotor as an assembly (less reliable).
Nick
If the rotor is still riveted to the hub, and you drill out the rivets, mark the hub to rotor relationship, and reinstall in that same position.
Plasticman
03-25-2012, 12:56 PM
#22
Le Mans Master
The 63-68 C2 uses:
Inner bearing A6 or Timken Set 6
Outer Bearing A2, or Timken Set 2
Inner Seal 7934S Same number for National or Timken
I prefer the National Seal
Bearings Good brands are Timken, SKF, CR or Chicago Rawhide, NTN or BCA / National.
Sorry to say most of these are no longer made in the USA. Maybe you can find some old inventory but these bearings are very popular sizes and fit many vehicles.
Inner bearing A6 or Timken Set 6
Outer Bearing A2, or Timken Set 2
Inner Seal 7934S Same number for National or Timken
I prefer the National Seal
Bearings Good brands are Timken, SKF, CR or Chicago Rawhide, NTN or BCA / National.
Sorry to say most of these are no longer made in the USA. Maybe you can find some old inventory but these bearings are very popular sizes and fit many vehicles.
03-25-2012, 08:12 PM
#23
Melting Slicks
Thread Starter
Purchased a Timken Set 2 and Set 6. Both said Made in USA. When I removed my caliper this time and compressed the pistons it leaked like crazy. Guess this was my problem. With a rented press from AZ, the races when in without any issue.
Got the wheels back together, caliper replaced, and went for a ride with a nice firm pedal.
Here's the rub..... I'm cleaning everything up and pick up an outer bearing to look at the marking. Notice it's timken (one side on the old bearnings was Timken) and the grease looks grey. Uh oh. I packed the old bearings with some generic disc brake grease which was black. So ....I smell it and got a whiff of Moly which is the new grease for sure and a telltale sign that I messed up.
I accidentally INSTALLED AN OLD OUTER BEARING and have the new one all packed and ready to go sitting in a big.. I'm a dummy
Must have grabbed it by accident. At least it's the outer bearing which means I don't have to remove the caliper. Still a PITA with KOs.
Brian
p.s. Nick - thanks for the offer. AZ had them in stock so I grabbed them. $54 for outer/inner sets. Note Rock Auto had the same sets for $28 shipped. AZ gave me a 10% discount when I attempted a price match.
Got the wheels back together, caliper replaced, and went for a ride with a nice firm pedal.
Here's the rub..... I'm cleaning everything up and pick up an outer bearing to look at the marking. Notice it's timken (one side on the old bearnings was Timken) and the grease looks grey. Uh oh. I packed the old bearings with some generic disc brake grease which was black. So ....I smell it and got a whiff of Moly which is the new grease for sure and a telltale sign that I messed up.
I accidentally INSTALLED AN OLD OUTER BEARING and have the new one all packed and ready to go sitting in a big.. I'm a dummy
Must have grabbed it by accident. At least it's the outer bearing which means I don't have to remove the caliper. Still a PITA with KOs.Brian
p.s. Nick - thanks for the offer. AZ had them in stock so I grabbed them. $54 for outer/inner sets. Note Rock Auto had the same sets for $28 shipped. AZ gave me a 10% discount when I attempted a price match.
03-27-2012, 02:40 PM
#24
Le Mans Master
Brian you are and honest man, this is one of those mistakes that allows you to get better with no damage done. Glad you got the tension properly set without doing any real damage. ( I think I might have fixed this one quietly and never told I put the old one back in by mistake, trust me if you turn wrenches long enough something like this will happen ) Glad they were USA made.
03-27-2012, 03:39 PM
#25
Team Owner
Member Since: Oct 2000
Location: Washington Michigan
Posts: 38,899
Received 1,862 Likes
on
1,104 Posts
It's also worth noting that there are TWO cotter pin holes drilled through the spindle - one vertical, and one horizontal; that gives you a pinnable position each 1/12th of a turn of the nut, so you don't have to go another full flat loose if you don't catch a pin hole after backing the nut off one flat from the 12 ft-lbs. point. Each full turn of the nut moves it .050", so each 1/12th of a turn moves it .004". 
