Heat affected wheel bearings?

[blair]

Car - T-18

motor - poo

use - dori

problem - im putting 86 struts in the t-18. The bearings have seen better days.

occurs/started when - today, when i pulled them out to degrease,clean and regrease!

personal situation - One Bearing is gone Dark Charcoal, like almost black, im presuming from to much HEAT. Its only the casing, as the rollers are still perfect shinny with no scores at all. Still roll's smooth and long aswel. So the question is

-Whats actually wrong with using/reusing a heat affected bearing?
-Are they now more brittle and have a higher chance of Imposion?
-before i get people bombarding this thread saying "just replace it anyway", this car has cost me wayyyy more than i ever imagined so its not happening unless i find a ligit reason to :)

ta

[Dish]

Well it's obvious the bearing isn't working as it's suposed to, even though it may feel all fine and look sweet, it's binding/causing friction slightly enough to cause a fare whack of heat to discolour it.

The only thing wrong is that it will be prone to collapsing, sure it might be all sweet for a while, but usually when they get to that point shit starts to warp and fuckout and then it will just shit itself, one of my axle bearings did it, aint cool when you're driving along.

I know it's not the same model but I ordered a rear axle bearing kit for an ra60 and old mate at repco gave me a front bearing kit instead came in at $27.99 for one side. So for $60 and an hour it's worth doing.

[Skylar]

I'm interested. Please run it and tell me if it ends in catastrophe.

Sounds like the sort of thing I would do.

[ke70dave]

hey blair, wanna take some pics of the bearing?

im interested to see the discoloration.

black charcoal doesn't really sound like a thing from heat though, doesn't metal usually go blueish when effected by heat?

you must have some serious heat in there!!! is the stub axel slightly bent? causing it to heat up that much? if its that bad i would have thought the bearing would destroy itself before heating up that much.

maybe the bloke before you did that big nut up too tight? causing excess pressure on the bearings? there is a torque setting for that nut in the manual (well i think its a torque setting on the hub spinning once the nut is done up)

if its that bad you should be able to feel clearance in the wheel bearing. wack it all back together, put a wheel on. and grab the top and bottom of the wheel. and push/pull it back and forward. this puts a fair bit of pressure on the bearings and if there is any clearance you should feel it. if you don't feel anything, rotate the wheel around and try from a different angle. if you still dont feel anything then id say your pretty right.

still though....why the heck is it that black!

[orido]

is there any difference in the brands of wheel bearing or are the all the same ?

[sundee]

correct me if im wrong, but if it were to be black from extreme heating and cooling, not that even black is in the metal temp colour chart, wouldnt the bearing have to get white hot 1st. thats over 1200'C
kinda strange, for 15 bux - who cares! throw it in the bin and save buying a new strut and hub and another bearing when this "black" one finally craps out.

[blair]

i bought new ones for $5.50 each cause im a povo khent..

made in AUS! uh-oh...

[blair]

for dave!

note: ignore the green tinge.. thats just crappy nokia photos for you!
beeive me.. its BLACK. The rollers however are perfectly shiny chrome...
maybe for some odd odd reason its actually painted black??
http://www.ae86drivingclub.com.au/dcimages/1/4/9/23208.jpg

[greeneyes]

I'd say it left the factory like that! It woud be difficult for any problem to evenly colour just the cage and not affect the rollers.

Use it!!

(and you probably know that there should be the smallest amount of play with your hands on top and bottom of the wheel. There needs to be room for the grease to stay coated on the rollers)

[boost+k]

they look fine to me...

black discolouration is normally from prolonged over heating and then cooling, it does something to the metal like when you anneal something

i work in aviation and if something like a shaft has black colouring it goes straight in the bin, even if it passes hardness and crack testing