Joe,
How are you installing the new bearings. When ball bearings are installed in
a housing you CANNOT PUSH ON THE INNER RACE or the hardened balls will put
permanent dents in the outer race which will cause the bearing to fail
prematurely fail. When the bearings are installed into the housing you may
only press on the outer race. Also, is there a spacer between the inner
races of both bearings (I'm assuming there are two to support the arbor)? It
is possible the spacer is a little too short causing you to preload the
inner races of both bearings which can cause them to fail if the loading is
excessive? I don't think your dado head should be an issue unless something
you are putting on the arbor is out of balance or the head is too large a
diameter for the saw. Delta recommends only a 6" dado head be used on their
Unisaws to prevent bearing wear. Belt tightness shouldn't be an issue either
unless it is extremely excessive. Look at the belt tension of components on
a car engine. There is enormous, constant stress on the bearings, they run
in a very hot situation, at high RPM's and yet remain serviceable for years.
Hope this helps,

Bob
"Joe" wrote in message
...
I know the opinion of the "wreck" on Craftsman products but the wife
bought me one of those Craftsman tablesaws with the router extension
wing for father's day about 3 years ago for a good price. With a
Vega replacement fence, a router fence based on Norm's Deluxe Router
station and an 890 PC router bolted on it with a link belt driving a
Forest Woodworker II, it cuts like a dream.

Now the problem:

After about 4 mos. of regular use I started getting noise from the
arbor bearings and returned it for a new one - same model. Another 4
mos., same story except I opted for in-home service. The serviceman
took one listen and said "yep, bad bearings". He ordered new arbor
bearings, arbor housing and a new arbor to be sent directly to me and
told me to call him back if I needed him to install the parts. Long
story short - I have a complete set of bearing pullers and changed
them out myself and reinstalled the assembly - piece of cake. The
only problem is I have to keep repeating this process. The last time
I ordered bearings from Sears, they were USA made but that didn't make
any difference neither did the China made bearings I bought local.

Now the saw is 3 years old and Sears has decided to raise the price of
the bearings to almost $35 a piece!

Does anyone know of a brand/supplier of a high quality 6202Z 15mm id,
1 3/8 od shielded bearing that can stand the loads of a typical table
saw? I don't mind spending the money if I never have to replace them
again but this 4-8 month life cycle is getting ridiculous.

..Joe L