Update on 12-bolt O-axle gears
November 10th, 2013, 07:09 AM
#41
Registered User
Join Date: Jul 2013
Posts: 60
Maybe Wiki can do a better job of explaining it.
http://en.wikipedia.org/wiki/Differe...ical_device%29
" If the engine is running at a constant speed, the rotational speed of each driving wheel can vary, but the sum (or average) of the two wheels' speeds can not change. An increase in the speed of one wheel must be balanced by an equal decrease in the speed of the other."
Vice versa true. Decrease in one wheel must be balanced by an increase in the other.
Steve g
http://en.wikipedia.org/wiki/Differe...ical_device%29
" If the engine is running at a constant speed, the rotational speed of each driving wheel can vary, but the sum (or average) of the two wheels' speeds can not change. An increase in the speed of one wheel must be balanced by an equal decrease in the speed of the other."
Vice versa true. Decrease in one wheel must be balanced by an increase in the other.
Steve g
November 10th, 2013, 07:53 AM
#43
Registered User
Join Date: Jul 2013
Posts: 60
It's a very abstract concept and not easy to wrap your head around. I didn't wake up one morning knowing this.
I will say this, I have a great deal of respect for someone that sees it to this conclusion with a
.You've definitely got class.
Steve g
November 10th, 2013, 08:15 AM
#44
Registered User
Join Date: Jul 2009
Location: Brooklyn, NY
Posts: 1,943
The exact reason trac lock ford posi units are JUNK. One side clutch packs will have to do double duty. It is just a fact.
THINGS multiply when the clutch pack starts to get sloppy also ESPECIALLY drag racing when one tire lets loose. It does have to do with default and weight transfer also. The direct the spiders gears spin pins those clutches tighter on the one side and cause them to over heat while the other side is slightly looser getting some oil between the clutches.... I have seen one side clutch pack melted fused together. If you take apart as many posi units as we do you will see it is just the way it is....NO MATTER what the reason, it is what it is.
Jim
One side clutch packs will have to do double duty. It is just a fact. THINGS multiply when the clutch pack starts to get sloppy also ESPECIALLY drag racing when one tire lets loose. It does have to do with default and weight transfer also. The direct the spiders gears spin pins those clutches tighter on the one side and cause them to over heat while the other side is slightly looser getting some oil between the clutches.... I have seen one side clutch pack melted fused together. If you take apart as many posi units as we do you will see it is just the way it is....NO MATTER what the reason, it is what it is.
Jim
Or you can do it this way.
November 12th, 2013, 04:35 AM
#45
Registered User
Join Date: Jul 2006
Location: Richfield, Oh
Posts: 1,737
Clutch issue still not solved about one side burning up more than the other
Think I can still explain the clutch issue.
Since the carrier spins and the spider spin equal and opposite correct?
IE-
The right tire (passenger side) is the default on the burn out going forward... the carrier will spin in the same direction as the right side spider gear, pinion driving the ring gear in the same direction as the tire and side spider correct? So the other spider gear Driver side will either appear to stay suspended in the carrier as it is stuck to the ground that means the carrier is spinning past that spider gear in the opposite direction so that would MULTIPLE the affect of friction as an example like 2 cars accelerating at each other (driver side side gears and case) instead of passing each other side by side (passenger side). Does this make sense why one clutch pack would wear more than the other...Correct?
IE - like a car hitting a wall at 60mph is 60mph BUT if 2 cars hit head on at 60 mph they will multiple the MPH of impact.
Do you get that? That should explain that reason.... That is also how the unit gets its percentage of one tire spinning different speeds in the turns.
Got this from just watching the spider gears as they spin by turning the pinion and holding one driver axle. you will see relative to the spinning case the the driver side spider spins (appears relative to the case spinning and side gear opposing it twice as fast in the case as the opposing passenger spider relative to the case spinning the ring gear in a forward direction. We were missing something and I think this is it.
We are going to get this reason - why one side clutch gets worn more than the other.
JIm
Since the carrier spins and the spider spin equal and opposite correct?
IE-
The right tire (passenger side) is the default on the burn out going forward... the carrier will spin in the same direction as the right side spider gear, pinion driving the ring gear in the same direction as the tire and side spider correct? So the other spider gear Driver side will either appear to stay suspended in the carrier as it is stuck to the ground that means the carrier is spinning past that spider gear in the opposite direction so that would MULTIPLE the affect of friction as an example like 2 cars accelerating at each other (driver side side gears and case) instead of passing each other side by side (passenger side). Does this make sense why one clutch pack would wear more than the other...Correct?
IE - like a car hitting a wall at 60mph is 60mph BUT if 2 cars hit head on at 60 mph they will multiple the MPH of impact.
Do you get that? That should explain that reason.... That is also how the unit gets its percentage of one tire spinning different speeds in the turns.
Got this from just watching the spider gears as they spin by turning the pinion and holding one driver axle. you will see relative to the spinning case the the driver side spider spins (appears relative to the case spinning and side gear opposing it twice as fast in the case as the opposing passenger spider relative to the case spinning the ring gear in a forward direction. We were missing something and I think this is it.
We are going to get this reason - why one side clutch gets worn more than the other.
JIm
Last edited by monzaz; November 12th, 2013 at 06:25 AM.
November 12th, 2013, 06:45 AM
#46
Registered User
Join Date: Jul 2013
Posts: 60
Think I can still explain the clutch issue.
Since the carrier spins and the spider spin equal and opposite correct?
IE-
The right tire (passenger side) is the default on the burn out going forward... the carrier will spin in the same direction as the right side spider gear, pinion driving the ring gear in the same direction as the tire and side spider correct? So the other spider gear Driver side will either appear to stay suspended in the carrier as it is stuck to the ground that means the carrier is spinning past that spider gear in the opposite direction so that would MULTIPLE the affect of friction as an example like 2 cars accelerating at each other (driver side side gears and case) instead of passing each other side by side (passenger side). Does this make sense why one clutch pack would wear more than the other...Correct?
IE - like a car hitting a wall at 60mph is 60mph BUT if 2 cars hit head on at 60 mph they will multiple the MPH of impact.
Do you get that? That should explain that reason.... That is also how the unit gets its percentage of one tire spinning different speeds in the turns.
Got this from just watching the spider gears as they spin by turning the pinion and holding one driver axle. you will see relative to the spinning case the the driver side spider spins (appears relative to the case spinning and side gear opposing it twice as fast in the case as the opposing passenger spider relative to the case spinning the ring gear in a forward direction. We were missing something and I think this is it.
We are going to get this reason - why one side clutch gets worn more than the other.
JIm
Since the carrier spins and the spider spin equal and opposite correct?
IE-
The right tire (passenger side) is the default on the burn out going forward... the carrier will spin in the same direction as the right side spider gear, pinion driving the ring gear in the same direction as the tire and side spider correct? So the other spider gear Driver side will either appear to stay suspended in the carrier as it is stuck to the ground that means the carrier is spinning past that spider gear in the opposite direction so that would MULTIPLE the affect of friction as an example like 2 cars accelerating at each other (driver side side gears and case) instead of passing each other side by side (passenger side). Does this make sense why one clutch pack would wear more than the other...Correct?
IE - like a car hitting a wall at 60mph is 60mph BUT if 2 cars hit head on at 60 mph they will multiple the MPH of impact.
Do you get that? That should explain that reason.... That is also how the unit gets its percentage of one tire spinning different speeds in the turns.
Got this from just watching the spider gears as they spin by turning the pinion and holding one driver axle. you will see relative to the spinning case the the driver side spider spins (appears relative to the case spinning and side gear opposing it twice as fast in the case as the opposing passenger spider relative to the case spinning the ring gear in a forward direction. We were missing something and I think this is it.
We are going to get this reason - why one side clutch gets worn more than the other.
JIm
On the stationary wheel the steels are sliding forward against the stationary spiders at the same speed as the carrier is moving. Car moving 60 mph hits a stationary brick wall using your example.
On the other side, at the same time, the steels are still turning forward at the carrier speed but the fibres are moving at twice the carrier speed. Half that speed is canceled out because the movement is in the same direction. Car travelling a 120 mph runs into a car traveling 60 mph in the same direction. It's till only going 60 mph faster than the object it hit.
One wheel, 0 mph, carrier 60 mph other wheel 120 mph. 60 mph difference between the wheel and carrier on both sides.
The wheel that wants to spin is only doing that because of the direction the axle wants to twist, opposite the driveshaft rotation.
I'm more inclined to believe it has something to do with the direction oil flows around when the crown is churning up that oil. But it is a puzzler.
Steve g
November 12th, 2013, 07:34 AM
#47
Registered User
Join Date: Feb 2012
Location: Western Mass.
Posts: 77
As many of you know,the gears that were available for the 12-bolt O-axle were discontinued when Richmond was bought out by Motive,and have not been available for awhile now.
I spoke with Motive last Friday,October 25th,and the latest update is that production is "supposed" to start around March/April 2014. They will be making the same two ratios as before,3:42 and 3:90.
These will be Italian-made,and in my opinion,great quality,and a nicer gear,compared to the Richmonds.You can also expect the price to be more than they were before.
Hopefully there is truth to the production.
I spoke with Motive last Friday,October 25th,and the latest update is that production is "supposed" to start around March/April 2014. They will be making the same two ratios as before,3:42 and 3:90.
These will be Italian-made,and in my opinion,great quality,and a nicer gear,compared to the Richmonds.You can also expect the price to be more than they were before.
Hopefully there is truth to the production.
I hope this is true,I have been looking for a set of 3:42 for months. Will there be another post in the spring if the production starts?
November 12th, 2013, 08:08 AM
#48
Registered User
Join Date: Jul 2006
Location: Richfield, Oh
Posts: 1,737
Clutches and spider gear
I can't see that as the answer. The steel discs are tied to the case and the frictions tied to the axle gears.
On the stationary wheel the steels are sliding forward against the stationary spiders at the same speed as the carrier is moving. Car moving 60 mph hits a stationary brick wall using your example.
On the other side, at the same time, the steels are still turning forward at the carrier speed but the fibres are moving at twice the carrier speed. Half that speed is canceled out because the movement is in the same direction. Car travelling a 120 mph runs into a car traveling 60 mph in the same direction. It's till only going 60 mph faster than the object it hit.
One wheel, 0 mph, carrier 60 mph other wheel 120 mph. 60 mph difference between the wheel and carrier on both sides.
The wheel that wants to spin is only doing that because of the direction the axle wants to twist, opposite the driveshaft rotation.
I'm more inclined to believe it has something to do with the direction oil flows around when the crown is churning up that oil. But it is a puzzler.
Steve g
On the stationary wheel the steels are sliding forward against the stationary spiders at the same speed as the carrier is moving. Car moving 60 mph hits a stationary brick wall using your example.
On the other side, at the same time, the steels are still turning forward at the carrier speed but the fibres are moving at twice the carrier speed. Half that speed is canceled out because the movement is in the same direction. Car travelling a 120 mph runs into a car traveling 60 mph in the same direction. It's till only going 60 mph faster than the object it hit.
One wheel, 0 mph, carrier 60 mph other wheel 120 mph. 60 mph difference between the wheel and carrier on both sides.
The wheel that wants to spin is only doing that because of the direction the axle wants to twist, opposite the driveshaft rotation.
I'm more inclined to believe it has something to do with the direction oil flows around when the crown is churning up that oil. But it is a puzzler.
Steve g
I see what your saying but in a turn that is not true. only straight. Right? The spider gears have to increase or decrease the percentage of travel and there has to be a different speed factor so it is the relation of the side gears to the rotating carrier mass.... The carrier has to spin free from the side gears we know that. and we know that the outside wheel has to spin fastyer than the inside wheel ...SO there HAS to be a difference in the sliding of the clutches...HAS TO. it is in the relation ship of the forward travel of the carrier in relation to the side gear forward travel on each side.
Do you see that?
November 12th, 2013, 09:20 AM
#50
Registered User
Join Date: Jul 2013
Posts: 60
I see what your saying but in a turn that is not true. only straight. Right? The spider gears have to increase or decrease the percentage of travel and there has to be a different speed factor so it is the relation of the side gears to the rotating carrier mass.... The carrier has to spin free from the side gears we know that. and we know that the outside wheel has to spin fastyer than the inside wheel ...SO there HAS to be a difference in the sliding of the clutches...HAS TO. it is in the relation ship of the forward travel of the carrier in relation to the side gear forward travel on each side.
Do you see that?
Do you see that?
When going straignt, nothing inside the carrier is turning. All spiders and axle gears are stationary relative to the carrier. They are all just spinning around as one solid mass. Axle gears fixed to the carrier, so spiders can't turn.
When turning a corner or one wheel spinning, both the same thing only to different degrees, what's actually happening is that one wheels is moving forward ahead of the carrier and the other one is moving backwards. I was reluctant to bring this up because it makes it even more difficult to visualize. And the axle gear moving backwards is moving backwards the exact same amount as the other side is moving forward.
I know, I know, how can one side be moving backwards? It is, relative to the carrier only. Think about an open carrier, both wheels off the ground and the driveshaft locked (trans in park or in gear, engine off). Turn one wheel the other wheels turns backwards. We've all done that at some time. It turns backwards exactly the same amount as you turn the other one forward. Can't move more than the other one.
So how can one wheel be turning backwards in a corner? It's not. It's turning backwards in the carrier, but the carrier is moving forward at a much greater rate so in effect the wheel still moves forward. Think about standing at the front of a flat bed rail car travelling towards Chicago at 60 mph then walking backwards. I'm walking backwards relative to the rail car, but I'm still going to Chicago. And while I'm walking backwards I'm going to Chicago at a slightly slower rate than the car under me.
So, however much one axle turns forward of the carrier, the other has to move backwards in the carrier the exact same amount.
Go back and read the Wiki thing and look at the drawings. The sum/avg of the two axle speeds has to always equal the input speed. Whatever one is faster than the carrier, the other has to be slower by the same amount or they won't equal in averaging. Can't be any other way or you would pick up speed or lose speed, which we know doesn't happen.
I suspect what is happening is that while both clutches are slipping the same amount one is getting a cooling bath of oil while the other is not. The teeth on the pinion are throwing oil in one direction, the teeth on the ring gear very much resemble the vanes on a torque converter. All this has to influence the flow of oil in the housing.
But one thing I am absolutely certain off, both clutches slip the same amount, just in opposite directions.
Steve g
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