JR HAWK 9

iTrader: (3)

I replaced my carrier bearings after noticing they were bad after doing a gear swap. This is by far the worst of the two. It looks like just one of the roller bearings went bad and that's what caused most of the damage.

Here is what think may have caused them to go bad:
- when they installed my 4.10's a few years ago they may have over tightened the studs on my TA girdle that put pressure on the bearing caps
- or just some real crappy bearings...has anyone heard of "KOYO" bearings??

I replaced them with a set of Timken bearings and races.

I don't know why they got like this, any ideas?

keliente

iTrader: (22)

IMO it was just the fact that they were shitty knock-off bearings.

chicane

I say it was an assembly issue...... probably a combination of too much pre-load, debris in the housing and having the outer races at an angle when the carrier was loaded into the housing. It could also be a bearing alignment issue.

Koyo's are Asian OEM bearings. I have them in my chase truck which has 320K+ miles on it and it hasnt failed the four 1000 or three Baja 500's it has been in. I would not blame it on the bearing just yet, as I have put Koyo's to the test.

But in comparison, I would use Timken's if they made replacements for the Koyo's in my application..... but they dont. Timken is the bearing of choice.

chevy94c

Wow those look awful.

Scott@DrivelineSolutions

iTrader: (22)

Too much preload or KOYO had a bad day at their heat treating plant.

8a8mfh

iTrader: (3)

One of my carrier bearings looked like that at 35,000 miles, only in a 3/4" spot. Factory stock koyo bearings.

todddchi

iTrader: (3)

I had timkens in my 93 that looked the same way. Likely nothing you could have done about it.

CTSmechanic

iTrader: (2)

I dont see any blue arond the races which is odd but Im with scott looks like a bad heat treat...maybe the surface was too hard and became brittle maybe a little micro welding ...I had a Ring and pinion from motive a few years back that was made out of the wrong steel made in India go figure..after extensive testing by a lab it was determend to be made out of the same steel as Grade 5 unheat treated bolts.There are so many variables in MFg that sometimes you'll go crazy tryin to figure something out and you should accept you got some bunk parts..

alamantia

iTrader: (10)

So Koyo is supposed to be a good or cheap bering?

chicane

.... Its micro spalling.

And Koyo's are good bearings.... when OE. Im not to sure on their aftermarket replacements tho....

alamantia

iTrader: (10)

and i thought i was the only one who watched ill-will press...