wheel bearing question

[midniteblues]

I've got new rotors and new wheel bearings(with races).
the rotors come with races allready in them.
in the past I've allways removed the race and installed the race that came with the bearing just because they were made too work together.
either way I'll have a extra set of races.
i'm curious should i replace the races in the rotors or should i save the five min and leave them in

I've allways wandered about this

[Tx Firefighter]

I've always just left the new races in the rotors and thrown the races from the new bearings in the trash. Can't say I can justify it as right, but it's worked for me many times in the last 20 years. I am a stickler for using top grade parts though, so I fancy the parts are machined to the proper specifications when I get a new rotor and bearing set.

[TBONE1964]

If you ask any bearing manufacture, they will tell you the bearing and race are a matched set and should stay that way.

I work on semi's for a living and I am one to tell you if you don't follow this rule, you are asking for trouble. We are talking about 80,000 lbs rolling down the road and to get 1,000,000 miles, they have to stick with matched bearings.

In your case, you may just leave the races that came in the rotor and install the new bearings and be happy for the rest of your ownership. If it were me, I think I would take the extra time and install the matched races to the bearings and feel 100% sure you did the job the right way.

[sjarrett71]

I've always used the races that were pre-installed in the rotors. They do sell bearings without the races afterall (although I've found it cheaper to buy them in sets). Keep them well lubricated and clean and they will last a long long time.

[jocko]

Ditto. The odds that you damage the new race (although slim) are greater than a 'mis-matched set' failing. I leave the races in rotor.

One thing to consider where you might want to pull the race is if you buy expensive fed mogul bearing/race combo and you know you have a cheap rotor - then it might be worth it because odds are that the race is cheap also. Chinese bearings are dirt cheap for a reason...

What I WOULDN'T do is replace a rotor and NOT replace the bearings (i.e. put used bearings into a new race).

You ask a good question - this was something I wondered also when I did mine because I had the "extra" race. I purchased a quality set of fed mog bearings and a quality rotor, so I just left the race in the hub.

[SS Tim]

Its a coin toss with known quality rotors that have pre-installed races. But if there is any doubt replace them. There may be a slight difference in run out between the two but with the race not having been run or bedded if you will the difference would be minimal.

[cdowns]

get yourself synthetic wheel bearing grease// one of those small things that add up in end results if you have alot of small things to add up

[GMtrucknut!!]

Well my perspective is the wheel bearings are not made/machined at the same time so they are not technically matched. They are made on two different manufacturing lines and paired by the individual packaging them so using the bearing which are in the new rotors which were in them while maching them would give a true center.

[midniteblues]

Originally Posted by GMtrucknut!!

Well my perspective is the wheel bearings are not made/machined at the same time so they are not technically matched. They are made on two different manufacturing lines and paired by the individual packaging them so using the bearing which are in the new rotors which were in them while maching them would give a true center.

never gave that a thought but its a good point,in fact every reply has valid points I was allways mixed up between the two so I thought I would ask opionions.
If I'm working on my own stuff i usually pulled the races out If i was doing it for someone else I left'm in. but I've never had a problem either way. but as the tx firefighter said cant justify if its right or wrong

for what its worth timkin bearings and rayabestos rotors I'm not sure where these parts are as for quality but I've allways heard good things about both so thats what I went with.oh and yes valvoline synthetic bearing grease.