Green bearings or stock adjustable

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Penstarpurist

Penstarpurist

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Picked up a 3.55 center section at the swap meet today to put in my son's 8 3/4 going into his '71 valiant. The 8 3/4 donor car sat at the ocean for many years, so we are replacing all gaskets, axle bearings and seals. I know from reading that the first generation of bearings are crimped and don't allow any movement and dont work great for daily drivers. Read the MO400 is a new generation and are retainer clipped and much better for a daily driver car. Anyone running them for a long term and have feedback if they are worth the swap or should I just go back with the OEM stuff and run the adjustable? Got to buy new ones either way, but dont want to waste money on something that wont work long term. The car is a small block daily driver. Mostly in town miles, occasionally distance driving.
 
There is a lot of opinions going to be stated. My experience is I have used the green bearings on several projects form many years and they drove for years, without issues. I guess it will depend on how many miles and usage.
As a side note, The De Tomaso Pantera's had roller bearings in their rear wheel hubs from the factory. I have only seen one go bad, that was from getting water in it.
Good luck on your decision.
 
they are both good but like said if you decide green get the newer un crimped style . the green style is not nearly as messy if you change your 3rd member often .
 
jimjimjimmy said:
they are both good but like said if you decide green get the newer un crimped style . the green style is not nearly as messy if you change your 3rd member often .
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Both my cars have green bearings, 40K plus miles. Very easy with pumpkin changes.
 
Penstarpurist said:
Anyone running them for a long term and have feedback
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the green bearing in our dart have been in that rear since the 90's when the car the rear was in was a daily driver. lots of street miles and lots of getting the **** beat out them at the drag strip then a lot more street miles with cornering in mind and they are still going strong..

its personal preference. if you have all the adjusters and all there is nothing wrong with going stock style. then there is nothing wrong going with green either...
 
If you have any doubts, it's safer to go with stock.
I have never ran the green bearings, so i don't know how they will last.
 
I'll side step the argument and say this:

I prefer to keep my car stock or at least oem parts if I plan on traveling in the vehicle at all. Being too far from home with parts that are more readily ordered on the internet vs what's in the local parts bin sucks.

Personally, I'd run the oem bearings if that's what you have now and it ain't broke.
And if there's no water intrusion, give em fresh grease and go.
 
jos51700 said:
I prefer to keep my car stock or at least oem parts if I plan on traveling in the vehicle at all. Being too far from home with parts that are more readily ordered on the internet vs what's in the local parts bin sucks.
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does anyone even stock the factory bearings any more? can't imagine pepboys carrying them..lol
 
Real auto parts do carry the factory bearings and seals. But in reality, the reason I drive Mopars is because everything is so heavy duty. I don't have to fix something on the road. I used to drive 3 young kids from Maryland to South Dakota every summer by myself. No problems in a Mopar. I've changed a timing set on the side of the road on a Chevy before. Definitely not a fan.
 
Sounds like the green bearings have come a long way in being usable in a daily driver and not just straight line flogging. We do have all the original parts on the axle still, and an extra set on the shelf (if anyone needs I would sell our extras, but that's a different thread). I think the MO400 may be the way to go this time around. With the car being 95% or better in town driven and we have the AAA gold membership for towing out of town, if we develop a problem with them, it's a lesson learned and we can go back to the old time tested technology and put new adjustable bearings back in. And definitely no one around here stocks mopar OEM axle bearings on the shelf. Or the green bearings either for that matter. Sadly if it isn't a Chevy or a tuner ricer it's not on the shelf in my neighborhood.
 
Stock bearings are readily available through bearing distributors like Kaman. They are generally sold by bearing number, not application.

There are a lot of opinions but it's basically engineering. Are you driving the car more on winding roads or at the drag strip? Green bearings are designed for straight line use. Some manufacturers even put a disclaimer on their product saying "not for street use". There are always a hundred people who will say that they've been running them on the street for hundreds of thousands of miles with no problems. Many enthusiasts only drive their car to shows and at the dragstrip and green bearings will hold up fine.

But should you decide to get in a road race? The simple fact is that side stress is a destructive factor in straight roller bearing design no matter how well reinforced it is.. Hold the two bearings side by side and look at them: When you go down a winding mountain road at 100mph, you are putting stress on the side part of the green bearing that it was not designed to take.

Tapered roller bearings, on the other the other hand, are specifically designed to handle this side stress as a function of it's intended use. On the curves, the bearings are forced into the tapered race, minimizing the stress and the likelihood of failure.

It is a PITA to keep the adjuster and lock working and make certain that the sure grip unit has a thrust pin in it, so green bearings are easier, but overall OEM bearings are much safer.
 
I hope he isn't doing 100 mph corners in any car, lol, let alone a 71 valiant with old technology suspension and brakes. But he is a teenager so anything potentially stupid to do, he's probably considering it. Reading what dr diff has said of the mo400 ther are designed to hold side pressure and load no different than the OEM stuff of their time. Definitely have to give it some thought and debate before we make a decision on it. The vast majority of the driving is under 45 mph with the corners being a turn in an intersection or pulling into a parking space.
 
Well, it's about time for someone to cite a certain vendor's technically questionable publication about how terrible stock bearings are and how great the new green bearings are, and btw here's a link where certain vendor sells green bearings
 
jos51700 said:
Well, it's about time for someone to cite a certain vendor's technically questionable publication about how terrible stock bearings are and how great the new green bearings are, and btw here's a link where certain vendor sells green bearings
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I wasn't trying to justify one way or the other with a vendor's sales pitch of their product. I know like everyone else that vendors hype their products in an effort to sell them. I was just simply putting it out there for a reference as to what has been said of them. And I don't think that dr diff was bashing the OEM product, he said the new mo400 was comparable in performance to the OEM. Now he might of said how the old crimped style was inferior for daily drivers. But I think that is common knowledge at this point.
 
Penstarpurist said:
I hope he isn't doing 100 mph corners in any car, lol, let alone a 71 valiant with old technology suspension and brakes. But he is a teenager so anything potentially stupid to do, he's probably considering it. Reading what dr diff has said of the mo400 ther are designed to hold side pressure and load no different than the OEM stuff of their time. Definitely have to give it some thought and debate before we make a decision on it. The vast majority of the driving is under 45 mph with the corners being a turn in an intersection or pulling into a parking space.
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I have tried to get Axial load data from Green Bearings. It did not happen. It is readily available for the OEM tapered needle bearings from Timken or any real bearing manufacturer. Back in the day NASCAR used the OEM Bearings in Ford or Mopar rear ends.
 
gregpurcell said:
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It is a PITA to keep the adjuster and lock working and make certain that the sure grip unit has a thrust pin in it, so green bearings are easier, but overall OEM bearings are much safer.
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But wait... after '69-'70 sometime the green bearings were OEM!
 
I remember my teens in my mother's 71 Fury wagon with a 360 two barrel. I was the KING of road racing! I did 80 plus MPH runs over humps to get all 4 wheels in the air (long before Dukes of Hazard) then slammed it into low gear to turn the car sideways and slide through 90 degree bends. There weren't many muscle cars who could keep up with me (more because I was a lunatic, rather than the performance of the wagon) Other than the fact that the car kept breaking motor mounts, my parents didn't have a CLUE!

That's what always comes to mind whenever I think of replacing tapered bearings :)
 
69_340_GTS said:
But wait... after '69-'70 sometime the green bearings were OEM!
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I could be proven wrong but I do not recall any time where the Dana 60 or 8 3/4 ever used straight roller bearings from the factory. I could argue that the AAR Cudas and the TA Challengers which were built from the factory for road racing would NEVER have come with green bearings
 
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I think either are fine.......if you use the green bearings, make SURE you get the right ones. There was an early run of them that were not as good. Contact Cass at Dr Diff and he can tell you which ones to use and give you a good deal on them.

That said, the tapered roller factory style bearings worked well for a long time and they will hold up fine, too.
 
gregpurcell said:
I could be proven wrong but I do not recall any time where the Dana 60 or 8 3/4 ever used straight roller bearings from the factory. I could argue that the AAR Cudas and the TA Challengers which were built from the factory for road racing would NEVER have come with green bearings
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I had a '70 Road Runner 8.75" that had the green bearings OEM. I know this because I was the 1st person who ever had the rear end apart to replace the 3.23 peg-leg with a 3.91 Sure-grip. Is this "proof"? Besides, GM and Ford used the green-style bearing almost forever. But full-fledged race cars do not count... anything serious has full-floating axles, and when those AARs or TAs were converted to race cars the green bearings were obviously removed. But that isn't how Ma Mopar delivered them from the factory.
 
TAs and AARs did not EVER come with green bearings. They were built to run ralleys from the factory. No conversion needed. I am old enough to have run and built a few 70s Mopars IN the actual 70s. As a teen, I ordered all the performance and "hop up" information available at the time. I don't believe we were even TALKING about "green bearing" conversion in the 70's. I still have many of the old Mopar manual "bibles".
Someone else can correct me if I'm wrong, but I believe we started having this discussion in the late 80's or 90's when they first were available for race cars.
 
jos51700 said:
Well, it's about time for someone to cite a certain vendor's technically questionable publication about how terrible stock bearings are and how great the new green bearings are, and btw here's a link where certain vendor sells green bearings
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Cass’s description on his website isn’t “technically questionable”, and he certainly doesn’t say the stock bearings are “terrible” or that the green bearings are problem free. Read it again if that’s what you think, he lays out pros and cons for both styles. And both styles do have pros and cons.

Why Green Bearings? - Quality Body Shop Drivetrain

And he sells both types of bearings by the way. I’ve purchased the stock Timken bearings from him. The only thing he mentioned is that the axles I bought would come bare and I’d have to install the bearings myself because he didn’t have the adjusters so he couldn’t pre-install the bearings like he does with the green style bearings.


69_340_GTS said:
I had a '70 Road Runner 8.75" that had the green bearings OEM. I know this because I was the 1st person who ever had the rear end apart to replace the 3.23 peg-leg with a 3.91 Sure-grip. Is this "proof"? Besides, GM and Ford used the green-style bearing almost forever. But full-fledged race cars do not count... anything serious has full-floating axles, and when those AARs or TAs were converted to race cars the green bearings were obviously removed. But that isn't how Ma Mopar delivered them from the factory.
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Not sure what you remember, but 8 3/4’s didn’t come with “green” style bearings from the factory. I realize “never” is a strong word with Ma Mopar, but if you really did find that type of bearing in your 8 3/4 it was an anomaly, not something the factory switched over to. Find me a factory manual showing those bearings in an 8 3/4, or a TSB or factory bulletin indicating their use.

The 8 3/4’s in my ‘71 Dart and ‘72 Challenger both had tapered bearings, and both appeared to have never been apart previously, both still possessing all the standard factory marks, gaskets, etc. I’ve seen more than a few original, ‘70+ 8 3/4’s with factory tapered bearings. They last damn near forever unless they’re submerged in water, and most of the 8 3/4 axle bearings I’ve encountered have been factory original.
 
My partner and i did a lot of work for local dealerships.
The scrap bins always had a generous supply of removed rear axle bearings...never a tapered roller.
The green style are assembly line friendly, cheap and great money makers for service departments.
I have never seen a failed tapered roller and they will last indefinitely unless water soaked.
 
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