I remember a while back there was great debate about "green" axle bearings in 8.75 diffs. I didn't pay attention at the time, but now I have reason to care.

What's the deal? Are they OK for the street?

Well, here we go again!



Put them in last year,got them from doctordiff.
So far they been good.Plenty of street and racing.

The units dr. diff sell are said to be the better of those available, that said I wouldn't use them unless the car had a reason to have them , meaning a SPOOL ...

They are more than fine for any street car. If you're going road racing hard, then you might want to keep the tapered bearings in there.

Green Bearings are ball bearings, versus the original tapered roller bearings.

In theory... you wouldn't want ball bearings on a autocross car, they don't handle side loads as well as tapered bearings.

On the street (again in theory) ball bearings would not live as long as roller bearings (ball bearings focus stress on a single point, rather than the bigger contact patch of a roller bearing that spreads the stress over a larger area).

On a race car, ball bearings should be fine, minimal side loading to stress them.

That said, Dr. Diff says Green Bearings are fine (and not wanting to put words in his mouth, that roller bearings are overkill). If Dr. Diff says they are okay, I'm okay with that.

Sorry. After I posted, I thought to search older posts. I see this issue has been thoroughly discussed. Should have looked first. I think I can gleen the info I need from older posts. My mistake, carry on...

Snap ring style (sealed ball) Green bearings are no different than MILLIONS of OEM wheel bearings installed in Ford 9", Ford 8", and numerous GM rearends over the years.

Are Red one's available? They would go nicely with my red brake calibers.

In theory... you wouldn't want ball bearings on a autocross car, they don't handle side loads as well as tapered bearings

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I've been using the Green Bearings for over a decade on my own and customers cars, 8.75 and DANA with no issuses or failures,...been slinging them around auto courses/tracks for years, as well as triple digit speeds, and countless thousands of street miles,....like everthing mechanically performed on a vehicle, installation error will result in failure, regardless of the chosen/prefered componet

That's a poor conclusion based on poor data Mr Dayclona. But this is moparts and usually the good technical information contained in threads is never even paid attention too.

Apparently these cars you speak of are not going very fast or handling too many g forces for very many miles. If the road course runs clockwise and the car is reasonably fast that left rear wheel bearing takes a lot of punishment. There have been major failures of the left bearing that I have witnessed at the track.

In the attached photo the Boss 302 mustang that runs even faster than my fast pig has had a bearing failure caused the hub to snap off the left axle. The wheel/tire/axle flange is in the left hand side of the photo where the 2 guys are standing. This is turn one at the end of the front straight.

The proper info here for the OP and any one else hoping to learn something relevant is if you are going to drive your old car like an old car the green bearing is fine. If you want to run with the big dogs leave the tapered bearings in and make sure they are lubricated and adjusted properly.

Weird things happen in extreme applications.

I replaced axles from circle track cars that pull the shaft out of the wheel bearing, or break the flange off the shaft inboard or outboard of the wheel bearing.

Sometimes full floating rearends are the best choice.

The MAIN thing you have to remember when working on an 8 3/4, is to take the chunk out and lay it up on a little glass patio table so it will stay clean.

I can say from personal experiance is Green exle bearings are like aluminum rocker arms, when running them on the street the question is are they going to fail or when are they going to fail.
Keep them off the street and the feer of walking home is gone.