I'm swapping the 3rd member in mt roadster from 4.77 gears to 4.30 gears this winter but had a nasty surprise when I pulled the axles. The press on bearings are physically broken on both sides? Has anyone seen this before? What could cause something like this?

i have never seen that bearing with that cover plate together

Have you had this apart before and know that they were not installed like that? It looks to me like they were damaged when they were installed on the axle.

The one side always had a bit of fluid on it but this was the first time I have pulled the axles since buying the car a couple years ago.

I'd take a real close look at the straightness of the housing and alignment of the ends. It looks like the rollers were trying to roll out of their grooves.

Thanks Guys other than an install or alignment issue the only thing I can think of is that I did have the car up on its side on 2 wheels one day when I got way loose and took out the 1.8th mile timing blocks. I would think those bearings could take that abuse though. Apparently it has 4.56 Pro Gears in there part # 80-0570-1 rather the 4.77's. So now I'm thinking a 4.11 might be better as the engine builder thinks it will run low nines with the new engine. I plan to double enter and run as much as I can next year so I'd like to keep the RPM's down on the big end.

I take it that the rear end is Ford nine inch style, yes or no If so check the housing for straigthnes by reinstalling the axles and measure off of the axle flanges out around 16 inches from center to the front, back and up and down, I use two steel carpenter squares, check the edges for straightness agianst each other I'm shocked that niether one of the outer races broke into two pieces DUDE, you dodge a big bullet

Yes the rear end is from a Ford 9"

Have you pulled the third member... I only seen that
once and a chunk of gear got in there... thats what
we ASSUMED because there was a chunk of gear right
near it

Were the broken pieces from the bearings inside?

Make sure the ends of the axles are not pre-loading against them selves or on the inside of the carrier.

The 3rd member looks perfect. The bearings were in one piece until I pulled them out of the housing then the chunks fell off. The housing was clean of shrapnel as well.

either as previously stated, the bearings could have been damaged when they were pressed on. if u had the car on 2 wheels as u mentioned, it could have put excess pressure on the bearings.