Rear Spline Lub

[Ricky-D]

It may be that those two holes are from an early decision made by Honda to lubricate the pinion cup area with the oil and that would explain the seal in one respect.

I recall the holes are cast and maybe Honda determined it cheaper to simply leave the design alone. Now, if those holes are (still) machined, I will be the first to say that this assumption is completely wrong.

i feel the oil getting into the pinion is not dependable due to the low level of oil in relation to the position of the pinion and the close proximity of the bearing race that actually (partially) blocks the holes and not to disregard the position of the complete assembly which does not seem to lend itself to easy transfer of the differential oil to the pinion cup.

If the differential were filled to a higher running level I would think there is a better chance to get the oil into the pinion cup but the down side most likely would be greater heat retention and leaking oil from hitherto unknown places.

***

[art]

I'm thinking a mist of oil will get thru due to a difference of air pressure between the rear housing an the pinion cup.It would not need much oil to lube the cup an keep it from drying out.After this last time when I checked the cup it was wet enough that oil from the rear drive was the only explanation,It was not from the grease braking down

[Valkpilot]

It may be that those two holes are from an early decision made by Honda to lubricate the pinion cup area with the oil and that would explain the seal in one respect.

I recall the holes are cast and maybe Honda determined it cheaper to simply leave the design alone. Now, if those holes are (still) machined, I will be the first to say that this assumption is completely wrong.

i feel the oil getting into the pinion is not dependable due to the low level of oil in relation to the position of the pinion and the close proximity of the bearing race that actually (partially) blocks the holes and not to disregard the position of the complete assembly which does not seem to lend itself to easy transfer of the differential oil to the pinion cup.

If the differential were filled to a higher running level I would think there is a better chance to get the oil into the pinion cup but the down side most likely would be greater heat retention and leaking oil from hitherto unknown places.

***

Your position was pretty well debunked by Daniel Meyer and others in this thread: http://www.valkyrieforum.com/bbs/index.php/topic,20177.0.html

[98valk]

It may be that those two holes are from an early decision made by Honda to lubricate the pinion cup area with the oil and that would explain the seal in one respect.

I recall the holes are cast and maybe Honda determined it cheaper to simply leave the design alone. Now, if those holes are (still) machined, I will be the first to say that this assumption is completely wrong.

i feel the oil getting into the pinion is not dependable due to the low level of oil in relation to the position of the pinion and the close proximity of the bearing race that actually (partially) blocks the holes and not to disregard the position of the complete assembly which does not seem to lend itself to easy transfer of the differential oil to the pinion cup.

If the differential were filled to a higher running level I would think there is a better chance to get the oil into the pinion cup but the down side most likely would be greater heat retention and leaking oil from hitherto unknown places.

***

Your position was pretty well debunked by Daniel Meyer and others in this thread: http://www.valkyrieforum.com/bbs/index.php/topic,20177.0.html

from an engineering stand point DM is wrong. once installed the gear oil will have to travel uphill to get to those holes and there is no type of vanes/gears to help the oil travel uphill. it is not designed to do that and honda would not design it that way.
they are secondary vent holes for expansion of the fluid/air during extreme heat usage combined with high ambient temp and most likely vent holes for the spline to shaft connection area. splines can generate a lot of heat.  the main vent hole is the chrome cap on top. improper oil level will cause the gear oil to enter that area. 30k miles and I have never had gear oil in that area. I have stated before if gear oil is in there something is wrong. the moly paste is what provides lubrication and nothing else.
how many are 100% sure they didn't overfill the rear drive and used the correct tech manual procedure.

[RonW]

wasn't there an idea about tagging the gear oil by adding food coloring to it?

[Valkpilot]

I must respectfully disagree.  I think there is a good case for drive oil providing lube for the pinion.

from an engineering stand point DM is wrong. once installed the gear oil will have to travel uphill to get to those holes and there is no type of vanes/gears to help the oil travel uphill. it is not designed to do that and honda would not design it that way.

I don't think it travels uphill in the sense that liquid oil is flowing uphill against gravity.  Movement of the gears churns the drive oil, slinging it everywhere within the pumpkin.  This flung fluid is availabe for pickup by the angled hole in the side of the pinion cup.

they are secondary vent holes for expansion of the fluid/air during extreme heat usage combined with high ambient temp and most likely vent holes for the spline to shaft connection area. splines can generate a lot of heat.  the main vent hole is the chrome cap on top.

If they are merely vent holes, what is the purpose of their unique shape and placement?  Also, if they are vent holes, then the drive shaft seal at the end of the pinion cup isn't a seal at all.

improper oil level will cause the gear oil to enter that area.

True.

30k miles and I have never had gear oil in that area. I have stated before if gear oil is in there something is wrong.

I don't believe the schematics and the actual assembly substantiate this assertion.  There's nothing that seals the pinion cup holes off from oil.  You can test this by laying the pumpkin on the ground with the pinion cup down after  thoroughly cleaning the pinion cup and the holes at the bottom. Oil will easily find its way into the cup.  It's an easy experiment to conduct.

the moly paste is what provides lubrication and nothing else.

The manual calls for moly grease, not paste.  The difference in moly content is substantial, something like 3% moly for the grease and 60% moly for the paste.  And, the manual specifies very little grease: 0.02 ounces on the drive shaft end and 0.08 ounces on the pinion cup splines.   Many pictures have been posted here of pinion joints "wet" with lube.  I think this demonstrates that the drive oil is supplementing the small amount of grease.

how many are 100% sure they didn't overfill the rear drive and used the correct tech manual procedure.

I can't speak for others, but I'm sure.

[98valk]

should have typed grease instead of paste.

if one researches moly and what it does and what gear oil cannot do for splines one will realize that honda did not design those holes to provide gear oil to the splines.

"I don't think it travels uphill in the sense that liquid oil is flowing uphill against gravity.  Movement of the gears churns the drive oil, slinging it everywhere within the pumpkin.  This flung fluid is availabe for pickup by the angled hole in the side of the pinion cup."

the cut away dwg does not support that, esp when it is in the installed position. the dwg shows the pinion holes flush up against the bearings and there are seals also. if oil is coming through the holes there is a problem elsewear, they are not lube holes.

anyway I'm done with this discussion, can't fight emotional feelings with sound engineering principles. just like the seafoam religion, sure it cleans carbs, but once it gets to the hot intake valve it solidifies on the back of the valve reducing flow, power and mpg. and here is another one "I feel it's cheap insurnace to change out my syn oil every 3k miles", I have done used oil analysis that proves honda is right when it specifies 8k oil change and this was syn 10w30 oil. but feelings always trump facts.
rant over

[Valkpilot]

should have typed grease instead of paste.

if one researches moly and what it does and what gear oil cannot do for splines one will realize that honda did not design those holes to provide gear oil to the splines.

"I don't think it travels uphill in the sense that liquid oil is flowing uphill against gravity.  Movement of the gears churns the drive oil, slinging it everywhere within the pumpkin.  This flung fluid is availabe for pickup by the angled hole in the side of the pinion cup."

the cut away dwg does not support that, esp when it is in the installed position. the dwg shows the pinion holes flush up against the bearings and there are seals also. if oil is coming through the holes there is a problem elsewear, they are not lube holes.

anyway I'm done with this discussion, can't fight emotional feelings with sound engineering principles. just like the seafoam religion, sure it cleans carbs, but once it gets to the hot intake valve it solidifies on the back of the valve reducing flow, power and mpg. and here is another one "I feel it's cheap insurnace to change out my syn oil every 3k miles", I have done used oil analysis that proves honda is right when it specifies 8k oil change and this was syn 10w30 oil. but feelings always trump facts.
rant over

CA, we agree on much, in this case the oil change intervals and dismay over how feelings seem to trump facts on this board.  Posts and whole threads sometimes disappear when facts overwhelm perception.

I'll ask a favor of you: The next time you service your pumpkin, clean the pinion, including clearing the holes in the bottom of the pinion cup.  Then (with drive oil in the pumpkin) balance the pumpkin upright with the pinion cup down acting as a pedestal supporting the pumpkin.

[98valk]

should have typed grease instead of paste.

if one researches moly and what it does and what gear oil cannot do for splines one will realize that honda did not design those holes to provide gear oil to the splines.

"I don't think it travels uphill in the sense that liquid oil is flowing uphill against gravity.  Movement of the gears churns the drive oil, slinging it everywhere within the pumpkin.  This flung fluid is availabe for pickup by the angled hole in the side of the pinion cup."

the cut away dwg does not support that, esp when it is in the installed position. the dwg shows the pinion holes flush up against the bearings and there are seals also. if oil is coming through the holes there is a problem elsewear, they are not lube holes.

anyway I'm done with this discussion, can't fight emotional feelings with sound engineering principles. just like the seafoam religion, sure it cleans carbs, but once it gets to the hot intake valve it solidifies on the back of the valve reducing flow, power and mpg. and here is another one "I feel it's cheap insurnace to change out my syn oil every 3k miles", I have done used oil analysis that proves honda is right when it specifies 8k oil change and this was syn 10w30 oil. but feelings always trump facts.
rant over

CA, we agree on much, in this case the oil change intervals and dismay over how feelings seem to trump facts on this board.  Posts and whole threads sometimes disappear when facts overwhelm perception.

I'll ask a favor of you: The next time you service your pumpkin, clean the pinion, including clearing the holes in the bottom of the pinion cup.  Then (with drive oil in the pumpkin) balance the pumpkin upright with the pinion cup down acting as a pedestal supporting the pumpkin.

Yes we do logically agree on much.

I know in that position it will drain oil out, just like if u turn an engine upside down oil will drain out. in both cases when they are in the normal operating position they will not drain oil out unless something is wrong. if u position it upside down with the chrome vent cap balancing the unit, oil will drain out, if in the operating position oil will not come out.
looking at the dwg again if oil is coming up through those holes either the seal is bad or the chrome vent cap is blocked, dirt, bugs nesting, etc.,
or,
my main position is that the holes are not there to lube the splines with gear oil. could some oil work its way through the holes due to various factors, slight overfill, expansion from high speed running in high ambient temp, fully loaded riding and then bottoming out the suspension whereas the drive shaft almost becomes horizontal with some of the other mentioned factors coming into play, some combination of any, sure it could, but it is not designed to, let alone for lubrication purposes of the splines.
For the possiblity which according to some has happened, it would seam Honda wanted the gear oil to expand and overflow there, rather than have it go out the top vent and then possibilty down the tire affecting traction.

[RP#62]

On every one I've ever fooled with, if I position the pumpkin level and then turn the coupling so that the holes are aligned vertically, oil will dribble out of the lower hole.  With the pumpkin bouncing up and down when you're in flight and the gears slinging the oil about, it doesn't take much to get oil into the coupling.  Now whether that was the engineer's intentions, that's a question that I don't think we'll answer unless someone has an in at Honda.  If the holes weren't intended for lube to the coupling, one of the most plausible explanations I've heard was Jeff K's hypothesis that they may be there so that when you install the drive shaft into the coupling, it vents the coupling so that the shaft will slide in without trapping pressure and possibly blowing the grease back out past the seal.

There are several sound engineering reasons why they may be there, but unless someone from Honda speaks up, we're just pooling our ignorance.

-RP

[Jeff K]

Oddly enough 12 years of discussing this was enough for me. That, car tires, oil, and Honda brand consumables. No need for more input.  

Come to think of it all my bikes should have burst into flames by now from using that terrifying Orange antifreeze!!   

[Ricky-D]

Assumptions are just that! Assumptions.

If Honda engineered that pinion to be lubricated with the pumpkin oil, I say Honda would have done a more thorough job of it (lubricating); Seeing that the majority of pinions are dry and only a few become wet with oil.......... And that amount of oil is very little.

This whole self lubrication theory is predicated alone by the thinnest of evidence of a couple of partially blocked holes that are on a angle rather than 90 degrees to the circumference.

I have only stated my opinion as have others on this subject.  Marrying is a personal decision left to those that prefer others to do their thinking for them.

***

[RP#62]

Marrying is a personal decision left to those that prefer others to do their thinking for them.

***

???

[Daniel Meyer]

I know we have to rehash this every couple months because it IS the internet...

But, please, I'm not guessing, and not making it up. I was (in a previous life) a Honda trained/certified mechanic.

I'm not really gonna rehash it here again. The search feature works pretty well.

Come to Inzane. I'll show you.

[98valk]

I know we have to rehash this every couple months because it IS the internet...

But, please, I'm not guessing, and not making it up. I was (in a previous life) a Honda trained/certified mechanic.

I'm not really gonna rehash it here again. The search feature works pretty well.

Come to Inzane. I'll show you.

means nothing, no offense but there are a lot of mechanics out there who think they know the engineering behind something but really don't, because they are not engineers nor do they work in the engineering field. If u are going to talk about how to take apart and rebuild a rear assembly, I'd listen to u, otherwise I won't on this subject.
My position, the holes are not lubrication holes for the splines that barely move and the moly grease as called out by honda is enough. it anything happens rust, dryness, etc, then something else is causing it, bad seals, improper installed seals, the spring on the back of the seal damaged/stretched etc.  No modern day engineer let alone a honda engineer would design those holes to lubricate the splines.
another reason is no engineer would require a mixing of gear oil and grease to lubricate the same thing. it is never a good idea to mix oil and grease.
http://www.machinerylubrication.com/Read/2020/mixing-lubricants-hazards
"Mixing oils and greases is not a good idea, and can have expensive production and safety repercussions. Good selection and lubricant identification systems are needed to ensure this does not happen."

[art]

I know we have to rehash this every couple months because it IS the internet...

But, please, I'm not guessing, and not making it up. I was (in a previous life) a Honda trained/certified mechanic.

I'm not really gonna rehash it here again. The search feature works pretty well.

Come to Inzane. I'll show you.

means nothing, no offense but there are a lot of mechanics out there who think they know the engineering behind something but really don't, because they are not engineers nor do they work in the engineering field. If u are going to talk about how to take apart and rebuild a rear assembly, I'd listen to u, otherwise I won't on this subject.
My position, the holes are not lubrication holes for the splines that barely move and the moly grease as called out by honda is enough. it anything happens rust, dryness, etc, then something else is causing it, bad seals, improper installed seals, the spring on the back of the seal damaged/stretched etc.  No modern day engineer let alone a honda engineer would design those holes to lubricate the splines.
another reason is no engineer would require a mixing of gear oil and grease to lubricate the same thing. it is never a good idea to mix oil and grease.
http://www.machinerylubrication.com/Read/2020/mixing-lubricants-hazards
"Mixing oils and greases is not a good idea, and can have expensive production and safety repercussions. Good selection and lubricant identification systems are needed to ensure this does not happen."

I agree oil and grease are not to mix.You may be right I don't know the reason for the holes.I'm just saying that some oil did get into the cup an the rear was not overfilled .My last pinion cup an shaft were junk because it ran dry after 45000 miles, My fault due to health problems an moving from my home to another.I replaced the cup an shaft an 8000 miles later I found this condition.I cleaned it up an will check it in another 8-10000 miles an see.

[hubcapsc]

Here's an interesting patent abstract:

Lubricating device for final drive gearing of power transmission unit

Abstract

In a final drive gearing of a power transmission unit, which comprises a drive pinion shaft supported by a pair of axially spaced bearings carried on an upright partition wall of a trans-axle casing and including a pinion in mesh with a crown wheel, an abdominal cavity is provided on the partition wall to receive lubrication oil dipped up by rotation of the crown wheel, and a lateral hole is provided through the partition wall to communicate the cavity into an annular space around the drive pinion shaft between the bearings.
Inventors:    Sanui; Yoshio (Okazaki, JP), Wakahara; Kaoru (Toyota, JP), Yasui; Yasuyoshi (Toyota, JP)
Assignee:    Toyota Jidosha Kogyo Kabushiki Kaisha (Aichi, JP)
Appl. No.:    05/927,690
Filed:    July 25, 1978


A more recent abstract...

Lubrication mechanism in final drive and differential units

Abstract

In a final drive and differential unit comprising a ring gear integral with a differential gear unit rotatably mounted within a carrier, and a drive pinion shaft supported by a pair of axially spaced bearings within a cylindrical support structure of the carrier, the shaft extends outwardly through an oil seal member mounted within an outer end portion of the support structure and is provided at its inner end with a drive pinion in mesh with the ring gear. The support structure is formed at one side thereof with an enlarged portion formed therein with an oil supply passage opening at its one end into the carrier at the same side as the ring gear and is formed at the other side thereof with another enlarged portion formed therein with an oil return passage opening at its opposite ends into the carrier and into a first annular space between the oil seal member and the bearing. The support structure is formed in its side wall with first and second lateral holes respectively for communication between the oil supply passage and a second annular space between the bearings and for communication between the oil supply passage and the first annular space. The lowermost edge of the second lateral hole is positioned below the lowermost edge of the first lateral hole to ensure the flow of lubricating oil into the first annular space passing across the second lateral hole.
Inventors:    Hori; Hiroshi (Toyota, JP), Taniyama; Kiyoshi (Toyota, JP)
Assignee:    Toyota Jidosha Kabushiki Kaisha (JP)
Appl. No.:    06/682,144
Filed:    December 17, 1984

[Ricky-D]

And what on earth, does that have to do with this discussion?

***

[Valkpilot]

And what on earth, does that have to do with this discussion?

***

It describes a variation of the oil pick up method we've been discussing.

[Ricky-D]

I don't get that at all!

The only commonality seems to be the mentioning of holes for transmission of lubrication and being a differential needing to get oiling to an outside bearing such as in an automotive rear end where the bearings are outboard of the internal gearing.

Don't see any reference to a pumping action that this thread is all about. (picking up oil from a lower supply and moving it vertically to lubricate an elevated area in a positive manner.

Which is what some seem to think is the design feature in the Honda pumpkin.

If there were some pictures or diagrams (which I am sure there is) it would become more clearly evident as to the applicability of the abstract to our discussion.

***

[Valkpilot]

I don't get that at all!

The only commonality seems to be the mentioning of holes for transmission of lubrication and being a differential needing to get oiling to an outside bearing such as in an automotive rear end where the bearings are outboard of the internal gearing.

Don't see any reference to a pumping action that this thread is all about. (picking up oil from a lower supply and moving it vertically to lubricate an elevated area in a positive manner.

Which is what some seem to think is the design feature in the Honda pumpkin.

If there were some pictures or diagrams (which I am sure there is) it would become more clearly evident as to the applicability of the abstract to our discussion.

***

This is the heart of it:

The support structure is formed in its side wall with first and second lateral holes respectively for communication between the oil supply passage and a second annular space between the bearings and for communication between the oil supply passage and the first annular space. The lowermost edge of the second lateral hole is positioned below the lowermost edge of the first lateral hole to ensure the flow of lubricating oil into the first annular space passing across the second lateral hole.