[TR] IRS stub axle bearings

[Michael Porter]

Randall wrote:
> I see where TRF offers 3 different grades of IRS stub axle bearings
> (134465), being "standard", "Japan" (which I assume is NTN), and "high
> quality" (which appears to be SKF).  With almost a 6:1 ratio in price !
>
> Does anyone have experiences to share with the standard or NTN bearings ?
>
> I'm pulling the Stag's diff for other reasons, just noticed that the stub
> axle bearings were a bit loose ... but $115/bearing seems a bit steep ?
>
>   

SKF is Swedish, I think.  They're a good quality bearing, probably as 
good as Timken.


You might be able to get better quality at a good price by getting the 
existing bearing numbers and doing a little investigation with them at a 
local industrial supply house's interchange books.
 

Here's a hint.  Almost every manufacturer has more than one line of 
bearings.  In the US, these are defined by ABEC, and the grades run from 
1-7.  1 is the cheapest and is also defined as "automotive grade."  
Therefore, most mass manufacturers buy ABEC-1.  If they last the 
warranty period, they've done their job.


Over twenty years ago, I worked for a start-up company building 
prototypes.  When I got there, they had a cheap Korean mill/drill that 
wasn't suited for the work they were expecting it to do, and after a few 
months, I managed to get them buy a cheap Taiwanese Bridgeport copy.  
After about eight months of very, very hard work, some of it by people 
who really didn't care about the machinery, the spindle bearings had 
started to wear and were rumbling a bit.  To directly replace the 
bearings (grease-lubricated), top and bottom, was going to cost about 
$60 at the time.  Since they'd worn out in less than a year, I didn't 
want to go through that every year, so I opted for ABEC-7 bearings, put 
the quill in the lathe and machined a pocket in the nose for a lip seal, 
and filled the quill with spindle oil.  It was still working well when 
the company died five years later.  I think the price spread for the 
bearings then was $60 for ABEC-1 to $160 for ABEC-7 from the same 
manufacturer.


At that job, I bought a lot of bearings which had to run in harsh 
environments--extreme cold, abrasive mineral dusts with positive air 
pressure internally, etc.--so, buying replacements for equipment that 
ran periodically for testing (in a company always strapped for money) 
was an exercise in finding the cheapest possible that would last long 
enough to do the testing, so I was always looking for deals.  I used a 
lot of NTN bearings in various applications, and they didn't run any 
better or worse than any other.  An ABEC-5 (or -7) from the cheapest 
manufacturer is probably going to be a better bearing than an ABEC-1 
from the most expensive source.


If you want the best available in the US, look at the Timken interchange 
lists online, but be prepared to pay as much, or more, than SKFs.


Cheers.

-- 


Michael Porter
Roswell, NM


Never let anyone drive you crazy when you know it's within walking distance....