Diff question!

[Swinborg]

First question!!!

So today I had a nightmare getting g the rear wheel off as the spider was stuck fast on the diff.  Thiat ment taking the diff off the swing arm to get the rear wheel removed!!!
So drive shaft was stuck on the diff and after I got that out, diff oil came out of the socket where the drive shaft sat.  Is this normal???
If so what stops the grease getting washed away by normal operation?
What stops the moly grease getting into the diff?
Appreciate if any one can help!!!

[Chrisj CMA]

It is normal for a little final drive fluid to migrate into the pinion joint. I have never worried about a small amount of moly getting into the final drive oil. It can’t hurt anything but I don’t see it going that way.

[The emperor has no clothes]

If it happens to you again, there is a slot on the underside where you can separate the star gear with a screwdriver.

[Swinborg]

Fellas,

This is great!

Thank you both for your advice.  Really appreciated!

Max

[98valk]

Grease is oil held in suspension by different thickeners, oil is the lubricate.
Grease works due to the thickeners to release the oil very very slowly as needed to provide lubrication. so that is pretty much the oil you saw and not final drive gear oil.

[The emperor has no clothes]

The gear oil can easily flow into the pinion cup. Leave it with the cup pointed downward and you will see it pretty soon.

[98valk]

The gear oil can easily flow into the pinion cup. Leave it with the cup pointed downward and you will see it pretty soon.

but it doesn't during normal operation, correct normal installation and with the correct fluid amount and level.
the open pathway is for air expansion along with the vent cap, during the final drive heat up and cool down cycles during normal operation.

[hubcapsc]

Sometimes my shaft is coated with lots of final drive fluid. Final drive
fluid smells and looks like final drive fluid, it doesn't seem ambiguous...



-Mike

[Valker]

That is SUPPOSED to happen. The two holes in the bottom of the pinion cup are a crude oil pump. One is to pull oil in, the other is a drain.

[98valk]

Sometimes my shaft is coated with lots of final drive fluid. Final drive
fluid smells and looks like final drive fluid, it doesn't seem ambiguous...



-Mike

mine has never looked like that. good chance your housing chrome vent is blocked

[98valk]

That is SUPPOSED to happen. The two holes in the bottom of the pinion cup are a crude oil pump. One is to pull oil in, the other is a drain.

the final drive is not designed to pump oil into the spline coupling area. those holes are vents and nothing more.

[turtle254]

Someone needs to find out what those  holes are really for? Because every one  has a different ideal what Honda design them for.

[98valk]

"To understand what happens when oil and grease mix, you must consider the grease manufacturing process. A grease's thickener is made first, and then oil is added to achieve the desired grade. Therefore, mixing oil and grease will change the ratio of the base oil to the thickener, resulting in a lower consistency grade. Combine this with the issues of viscosity and oil incompatibility and you have a recipe for disaster when lubricants are mixed."

https://www.machinerylubrication.com/Read/29792/lubricants-mixing-effects

[Valker]

That is SUPPOSED to happen. The two holes in the bottom of the pinion cup are a crude oil pump. One is to pull oil in, the other is a drain.

the final drive is not designed to pump oil into the spline coupling area. those holes are vents and nothing more.

We disagree. I'm ok with that.

[Pluggy]

Someone needs to find out what those  holes are really for? Because every one  has a different ideal what Honda design them for.

Oil seal #31 is intended to keep oil retained inside the gear case.

https://www.partzilla.com/catalog/honda/motorcycle/2003/gl1500cd-a-valkyrie/final-driven-gear

The two holes in #13 Joint, Pinion allow air to escape when the greased driveshaft is inserted.  These do the same thing as the little hole in the shaft of a ballpoint pen.  When the splines on the driveshaft appear oily, the grease that was applied has heen worked from a paste into a thick liquid.

You may find a leaking seal when you remove the final drive.   But, notice the oil level plug is well below that pinion joint.  That level, plus the seal, were intended to keep oil retained in the gear case.

[turtle254]

Where is "Daniel Meyer" on this point?

[Valker]

Oil seal #31 is intended to keep oil retained inside the gear case.

Now THAT makes sense.

[Chrisj CMA]

I work on a handful of Valkyrie’s. Mostly to R/R rear wheels. I see final drive oil in the pinion cup often. I can’t believe that’s all because of faulty seals. Is it a designed feature or an unintended side effect of vent holes?  It doesn’t seem to hurt anything. My advice is to clean the pinion cup thoroughly, lightly grease the splines of the driveshaft at both ends. Add the proper amount of final dive oil and assemble with the correct sequence. Then ride and don’t worry about it.

[Avanti]

My advice is to clean the pinion cup thoroughly, lightly grease the splines of the driveshaft at both ends. Add the proper amount of final dive oil and assemble with the correct sequence. Then ride and don’t worry about it.

This has always worked for me.

[Swinborg]

Fellas,

Lots of ideas and opinions!

How about about this (to also Capitulate to my mid ADHD) give me:

1 for ok for diff oil in the shaft cup
0 for it shouldn’t be there!

Just send me a 1 or a 0!!!!!

[RonW]

Max, save yourself a tonne and don't get involved with the pinion hole debate. Both sides make good points.


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As already stated, there's a courtesy slot in the dust ring to stick a screwdriver in and pry the 5-star flange loose from the pumpkin. So, the 5-star flange doesn't stick to the pumpkin but remains on the rear wheel.






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"..... the spider was stuck fast on the diff.  Thiat ment taking the diff off the swing arm to get the rear wheel removed"

You might have done yourself a favor though. If by chance you weren't aware ..... the '4 nuts' have to be loosened then tightened to specs only 'after' the rear axle is torqued to specs. In that sequence. Failure to observe the step may result in catastrophic failure of the spline joint. Ahem, tightening the 4 nuts lastly, insures the length of the pumpkin is perpendicularly aligned to the rear axle so the mating splines mesh properly. Other shaft driven bikes like the Goldwing don't have this quirk but it has been known to happen occasionally on Valks.

[The emperor has no clothes]

Swin, you’d be good listening to all the excellent points RonW has made. We also should point you to the shoptalk section on this site. A lot will help there. I’m sure many of us look forward to your progress and any help we can give. 

[rug_burn]

  Those holes in the pinion cup are supposed to be there, and should be cleaned and kept open.  That's what lubes the driveshaft splines in the long run.   And don't overdo the grease either.    Those shots above are how the splines are supposed to look.   At tire change time inspection, when the seals are still relatively new, and the splines well lubed with gear oil like that, I just put them back together until the next time.   They're good to go.
   That seal should be checked to ensure that it's soft and flexible.   They don't last that long, and they're cheap.  If they get hard with age, they crack, the outer part breaks off, and they leak out whatever grease is still there since it very often plugs up those pinion cup holes.   Then the splines wear off with powdery rust all around and you're stuck, hopefully close to home and shop.    No bueno.    
    It looks to me like the holes in the pinion cup are key to keeping the seal lubed, and getting maximum life out of it.   But as long as you're not too far from home, dont worry:  a new driveshaft, pinion cup and seal can be had for about $100 USD!   Less than a typical drive chain.

[98valk]

 Those holes in the pinion cup are supposed to be there, and should be cleaned and kept open.  That's what lubes the driveshaft splines in the long run.   And don't overdo the grease either.    Those shots above are how the splines are supposed to look.   At tire change time inspection, when the seals are still relatively new, and the splines well lubed with gear oil like that, I just put them back together until the next time.   They're good to go.
   That seal should be checked to ensure that it's soft and flexible.   They don't last that long, and they're cheap.  If they get hard with age, they crack, the outer part breaks off, and they leak out whatever grease is still there since it very often plugs up those pinion cup holes.   Then the splines wear off with powdery rust all around and you're stuck, hopefully close to home and shop.    No bueno.    
    It looks to me like the holes in the pinion cup are key to keeping the seal lubed, and getting maximum life out of it.   But as long as you're not too far from home, dont worry:  a new driveshaft, pinion cup and seal can be had for about $100 USD!   Less than a typical drive chain.

did u see my post, mixing gear oil and grease degrades both for almost zero protection. Honda would not what them combined for that reason.

to get maximum life it is important to have zero movement of the spline coupling by insuring all movement is by the U-Joint.
from my thread   https://www.valkyrieforum.com/bbs/index.php/topic,116696.40.html

So my conclusion is to make sure the U-Joint splines are correctly lubricated, to prevent the drive shaft to final drive splines aka spline coupling (SC) from wearing out. I also installed a new driveshaft to spline cup seal every other tire change.

The SC in a perfect application would have zero forward/rearward movement and would be submerged in oil which would result in zero wear and fretting. Fretting is a type of corrosion which gives that rust powder look. Is not from water intrusion. In some applications they actually glue the splines together to stop movement.

Honda provided the locking spring clip on the SC end of the drive shaft to help reduce movement of the SC, but it is still not a solid zero movement connection. So this is where the lubricated U-joint splines come into effect, thereby doing all of the movement, to reduce or actually eliminate any SC movement.

In a few of the links I provide it is stated that the SC splines should be hardened to greatly reduce wear.  Did Honda do this to the parts?, it doesn't seem like they did, since that would have been a much higher cost.

In my case I inadvertently mixed greases with different bases for the u-joint splines, by re-greasing and not cleaning off the old grease.
My fault, at the time, I didn't realize they had different bases. So what happened the greases started to dry out and not provide the easy sliding movement as needed and the SC failed in 17k miles.

For re-installing the U-Joint boot I coated the inside lips with silicone grease and it pops on with zero problems. suggest not to use a silicone spray which has petroleum products in it and other things which could degrade the boot material.

So to bring this all together, proper lubrication of the u-joint splines is extremely important and should be done every tire change to protect the SC. 
This time I used moly bearing chassis grease for the U-Joint for even more friction reduction and easier sliding.

For the SC I mixed TS-70 moly paste with some high temp grease so there would be about a 50/50 moly to grease ratio as recommended by the Dan Foss pdf which is a much higher percent of moly than the 3% moly grease the Honda manual calls for.

The following documents have some very good info about SCs and lubrication requirements.

https://www.machinerylubrication.com/Read/693/fretting-wear

https://www.powertransmission.com/issues/0214/spline-couplings.pdf

https://assets.danfoss.com/documents/76142/AI152986482538en-000304.pdf

https://www.eng-tips.com/viewthread.cfm?qid=423609

https://gearsolutions.com/departments/tooth-tips-a-brief-overview-of-splines/

https://www.eng-tips.com/viewthread.cfm?qid=383504

[Swinborg]

Hey guys,

This is really fascinating - this is the best forum I have ever been on, I been telling my friends here on the depth of knowledge is just remarkable!!!

I was wondering can you help out and show me a picture of the seals I should replace please?

Thanks again for all of your help

Max

[hubcapsc]

Where is "Daniel Meyer" on this point?

I shouldn't put words in his mouth so I'll say I believe
he depends 100% on final drive fluid lubing his pinion cup.

Last time I watched the final drive tech session he was putting
stuff back together. He looked at the pinion end of his drive
shaft and declined to put any lube on it. "If it needed any lube
I'd probably just dip it in some final drive fluid", I remember
him saying...

-Mike

[The emperor has no clothes]

Hey guys,

This is really fascinating - this is the best forum I have ever been on, I been telling my friends here on the depth of knowledge is just remarkable!!!

I was wondering can you help out and show me a picture of the seals I should replace please?

Thanks again for all of your help

Max

http://www.valkyrieriders.com/shoptalk/Elusive%203rd%20O-Ring.htm

There is also a plastic washer that is very important not to leave out. Don’t usually need to replace it unless it’s damaged.

http://www.valkyrieriders.com/shoptalk/rear_end_service.pptx

[RonW]

The seal (16) is on the swingarm page.

[RonW]

"There is also a plastic washer that is very important not to leave out. Don’t usually need to replace it unless it’s damaged."

The thrust washer is thin and translucent and difficult to see with grease on it, but it's in there. I believe it's teflon. I dunno if there'll be a problem if you put two thrust washers in there by mistake. (42616-MAJ-G20, Item 5 on the Rear Wheel oem page.)






A hazard is if unbeknownst the thrust washer falls on the floor and you fail to include it on reassembly.





Without the thrust washer, the mating surfaces will grind into each other from the back and forth motion of the cush drive and cause problems.




The 5-star driven flange is pegged to the rear wheel hub.




As said, the thrust washer protects the mating surfaces.

[Rio Wil]

I am with Valker as to the two holes serve as a crude oil pump and drain. Both holes are drilled straight through the bottom of the pinion cup, but one of the holes (as I recall) is also radially drilled into the side of one of the holes.....and it is also drilled at a slight angle.  Suggests to me this is more than a drain, but is a rudimentary oil scoop.  Here is another wild and unsubstantiated thought, I am guessing the refill from dry of 5.1 oz. is incorrect....bet that is the quantity to be used for the 1500 Goldwing diff. I am now using 6.1 oz. from dry and get a wet gear set and no leakage to suggest maybe over filling.....

[Valker]

I am with Valker as to the two holes serve as a crude oil pump and drain. Both holes are drilled straight through the bottom of the pinion cup, but one of the holes (as I recall) is also radially drilled into the side of one of the holes.....and it is also drilled at a slight angle.  Suggests to me this is more than a drain, but is a rudimentary oil scoop.  Here is another wild and unsubstantiated thought, I am guessing the refill from dry of 5.1 oz. is incorrect....bet that is the quantity to be used for the 1500 Goldwing diff. I am now using 6.1 oz. from dry and get a wet gear set and no leakage to suggest maybe over filling.....

I also "overfill" mine. I fill it on the side stand rather than level. No oil from the top vent.

[98valk]

I am with Valker as to the two holes serve as a crude oil pump and drain. Both holes are drilled straight through the bottom of the pinion cup, but one of the holes (as I recall) is also radially drilled into the side of one of the holes.....and it is also drilled at a slight angle.  Suggests to me this is more than a drain, but is a rudimentary oil scoop.  Here is another wild and unsubstantiated thought, I am guessing the refill from dry of 5.1 oz. is incorrect....bet that is the quantity to be used for the 1500 Goldwing diff. I am now using 6.1 oz. from dry and get a wet gear set and no leakage to suggest maybe over filling.....

there is only bearings and seals on the pinion shaft to which the pinion cup is attached to. There is not a crude type of oil pump on the shaft.
As I posted gear oil and grease are not compatible, mixing them is not good, resulting in zero protection. Honda would not have designed this intermixing on gear oil and grease to happen.   

I posted this before, unless too many ignore my posts or just don't believe me, however,
 Grease is Oil held in suspension by grease thickeners so as to release the oil as needed to lubricate the grease parts. Subjecting the grease to a higher heat than what it was designed for can also release more of the oil than normal, and the final drive does get very hot. so if one used cheaper grease one would see more oil in the pinion cup. Therefor seeing oil in the pinion cup is the oil in the grease that came out of suspension and NOT the gear oil coming up out of the final drive which has Zero mechanism for the oil to be crudely pumped up the shaft into the pinion cup area.

Again Honda would not what gear oil to mix with the pinion cup grease which would render both useless for lubricating properties.

[Rio Wil]

So why is one of the holes in the cup so oddly drilled when a straight drilling would do, just like the other hole?

[98valk]

So why is one of the holes in the cup so oddly drilled when a straight drilling would do, just like the other hole?

I look at a pinion cup I have from a Goldwing final drive and it has to straight thru holes with a hole drilled  into the side into the one straight hole. so that tells me that like a seal relief hole so the seal to pinion cup interface doesn't get impacted with grease, which would make the seal fail. That what it looks like to me. so if the valkyrie pinion cup one hole is drilled on an angle that would just save one less hole being drilled.

that's what I'm thinking or it just added protection to keep the gear oil from getting into the pinion cup and mixing with the spline coupling grease. or could be a relief hole to prevent a vacuum buildup in the seal to cup mating area. those are just design issues and fixes I saw over the yrs. I didn't work in detail for yrs with shafts and seals, most I got involved was the low pressure air system used to seal the propeller shafts going through the hull of the ships.

[Rio Wil]

I still don't think the drilling's in the pinion cup are completely understood, especially the drilling hole that is perpendicular  to and at a slight angle from center of one of the through holes.  All three of these holes are on the back side of the seal #31 as mentioned above. This allow a direct path for the holes to access final drive fluid.  I think as the cup spins , the angled hole will take up micro-sips of diff fluid and migrate it into the cup to assist in lubing the splines.  The concentration of moly at 60-70 percent by weight (or volume) doesnt leave a lot of room for oil to be suspended in the mixture and IMHO Honda figured out how to augment  the spline lube very simply. It is correct there is no oil  pump mechanism on this shaft, it is the angle of the hole drilled in the side of the cup. I also suspect that one can mix many different grease application that are formulated for lubing steel gears and splines with no loss of lube effectiveness. We use everything from blue waterproof grease to synthetic final drive fluids and they all get mixed up in the cup with no loss of  effectiveness.  I even use a 1/8 inch thick felt washer that resides between the end of the drive shaft and the pinion nut inside the cup.  It stays nice and wet with a combination of final drive fluid, blue waterproof grease and a splash moly or constant velocity joint  grease. No failures in  200K miles....that the hell, everyone has their witches brew....

[rug_burn]

I also "overfill" mine. I fill it on the side stand rather than level. No oil from the top vent.

That's how I do it, too.  Seems like it's just the right amount.    They must have planned it that way.

[Chrisj CMA]

I don’t think I have drained or filled a final drive while on the bike in ten years and I’ve done lots of them. It’s so much easier to do it on the workbench while r/r the rear wheel. Just pour in 150cc. No mess no hoses. No problem.

[RP#62]

The great pinon cup hole debate has been going on since this board's inception and on the VOA board before that and probably on the SIG board before that.  As far as I know, in 26 years, no one has ever produced any correspondence from Honda explaining the purpose of the holes, so we're all still theorizing.  For what it's worth, I myself am in the vent hole camp.  The pinon cup is lubed on assembly, it doesn't need additional lube from the differential.  The differential operates in an oil bath, it doesn't need periodic weepage of grease to contaminate the oil.  The differential has it's own vent, it doesn't need to vent thru the pinion cup.  The pinion cup doesn't need to vent anywhere, but.... the air needs somewhere to go when you seat a lubed drive shaft into the pinion cup, especially when the parts are new and the tolerances tighter.  So, I think the holes are there to facilitate assembly, but I'm guessing too and this still doesn't explain the angle on the hole.

-RP

[rug_burn]

       Another point I would make is, from the original post,  If your star gear (with  the 5 'pins' that go into the rubber damper) is stuck in the rear drive, and you have a hard time getting it off,  it may be that it's stuck because the splines are nearly worn out, and you need to do some work on that rear end.     
    In RonW's shot of his rear drive, for your edification,  notice those splines whick look like they've nearly had it.   The splines on the star gear probably look the same.  Ron doesn't mention it, but he was probably replacing them I assume (I know, never assume).

[RonW]

No, not my spines. Internet pic (to illustrate the courtesy slot).