Green bearings for street

I kept encountering opposing opinions on whether the Green 8-3/4 axle bearing were suitable for street use. So I wrote to Bearing Technologies Ltd. to get the story directly from the source.

So here's the scoop:
The question is whether or not the RP400 bearing kit for Mopar 8-3/4" axles is suitable for street car applications. There has been a lot of discussion that since your catalog lists it under "Racing" that racing is the only application. Some have also said that the RP400 doesn't have enough lateral retention for street use. Others have said that they have several thousand miles of street use with the RP400s in their axles and have encountered no problem. Can you clear up the issue for me?

Dear XXXXXXXXX,

I received your question about the RP400. I'll try to answer this to the best of my ability. The original intent of the RP400 designed by the Green Bearing Company was meant as a replacement for the original taper bearings in the rear end of Chrysler / Mopar applications. It was made for street vehicles, as were all of Green's automotive bearings. Over time these products became favorites of custom axle manufacturers such as Moser Engineering, Strange Engineering and Mark Williams Enterprises. Green, being a job shop, manufactured a multitude of bearings for these outfits and started categorizing them as "Racing" bearings due to the fact that the products were becoming popular in that application.

There are a lot of these bearings on the road in both street applications as well as on track applications. As far as performance, all I can say is that these have been a staple in our product line with no revisions / issues for a long time. The experts on the performance of the product in various applications would be Moser or Strange. If you would like to contact them, you have to ask specifically for the RP400 with the fixed flange because there is a modified version (MO400) which was designed by request for Moser and has a slide over flange with a snap ring retainer.

You can visit www.moserengineering.com or call 260-726-6689 for more information.

Thank you for your interest in our products.

Best Regards,
Brian Graziadei

Bearing-Technologies LTD

Sounds like they definitely gave you a definitive answer there. The fact that they took any time to send you that email speaks volumes for their customer service.

Good info ! One for the archives for sure.

I don't know how there was ever a question about the green type bearing not being suitable for the road. Millions of vehicles are deliveried from the factory every day with a double row ball bearing assembly just like the green bearing. Anyone with a FWD car or a late model independant front suspension 4wd pick-up or SUV has that type of bearing on the front wheels. Even the 7.25, 8.25, 9.25 Chrysler rear ends use a straight roller bearing with C-clips retaining the axle.

Chrysler back in the 50's threw early 70's had a reputation for over engineering things (i.e., left had thread lug nuts) I put tapered roller bearings on the rear axle in the same category. Certainly a better design for retaining the axles but not necessary.

I think 9" fords use that type od bearing also.

I have been using the green bearings since they came out.

Infact I have them in all the cars and been in the runner for at least 12 years and it is a street car and I do not baby it and not one problem from it or any of the other cars.

A lot of the ones that know some one that has had a problem just jump on the bandwagon and run a product down and they don't even have them in there cars.

There are some many things out there using sealed bearing that the nay sayers heads would spin.

I have farm equipment with them in and not a failure with them but,I did have problems with roller bearing in some of the equipment.

For me I will keep using the green bearings and if I can replacement sealed for all my equipment I wopuld have them in it.

I have ball bearings in the rear axle of both trucks so I didn't ever think there should be a problem with them. I just kept seeing posts on various forums about Green bearings only suitable for racing. I couldn't imagine why so I thought I'd clear the issue up. Fortunately I got a prompt and clear response from Bearing Technologies Ltd. It's good to deal with a company who still has a personal touch. Anyway, I think part of the confusion about The Green Bearing application came from the "Guide To Chrysler 8-3/4" by Gary Lewallen/Doug Ahern in their excellent article covering the 8-3/4 axle that is readily found on the internet.

Bill

Can you tell me if you had ever to remove thethrust block from the carrier when using the green bearings?

Thanks Bob

rt383 said:

Bill

Can you tell me if you had ever to remove thethrust block from the carrier when using the green bearings?

Thanks Bob

Click to expand...

It really shouldn't matter other than if the thrust block is not in it's position when you slide the axle's in (in other words if part of it falls to one side or the other into the splined area that the axle is supposed to slide into as you pulled the axle out) it could interfere by preventing you from seating the axle all the way in and in turn cause you to need to pull the pumkin because you really don't want a piece like that floating around inside the rear end and without pulling the pumkin all you'll ever acomplish is to knock it down into the pumkin area, I would doubt you'd succesfully get it out any other way.

If you shine a flashlight inside of the axle tube and look into the end you should be able to see the thrust blocks still in place, as long as they are where they belong you can slide in your axles with green bearings in and never worry.

On an 8 3/4 axle for a b body - I installed the axles with green bearings and the thrust block in place. Not cool. The axles bottomed out on the block and the flanges of the green bearings started to bend when I started to tighten them down. Bad. So from my perspective you do need to remove the center thrust block from the differential if you intend to use green bearings.

Otherwise I never had a lick of problems with them, and Ford has used ball bearings in their famed 9 inch axles forever. Should be just fine for most uses except something like road racing.

Nice not having to do the end play adjustment as well, although I have not had problems setting the end play on axles with the tapered bearings either, just requires patience is all.

66dartgt is correct as the axles will bottum out before you can tighten up the nuts on the studs.

I know I forgot to take the thrust spacer out and thought I could get away with it no way could hardly get the nuts started on.

And I just did 3 complete rearend rebuilds and took out the spacer in the one and the buttons in the other two.

some maybe lucky and get the axles bolted in but I wouldn't want to force anything and thats what you would be doing.

just my .02