Drive Shaft -- Facts & Myths

Myth:

The drive shaft's splined connection at the final drive is lubricated by gear oil.

Fact:

The splined connections at both ends of the drive shaft are lubricated with lithium soap based grease or equivalent. Many have used the Honda Moly 60 Paste with good results. Moly offers the lowest friction and best protection of all commercially available lubricants. Moly is a solid lubricant which can withstand extreme pressures, and temperatures up to 1500 DegF. The universal joint splines and drive shaft splines can all be lubricated with these greases.

Leakage of the final drive gear oil is controlled with three oil seals and two O-rings. The oil seal and O-ring controlling leakage around the final drive's pinion gear are located so that no oil should reach the splined gear coupling which interfaces with the drive shaft. The drive shaft is splined to the coupling and that greased interface is protected from dirt and moisture contamination by a flexible dust seal mounted on the drive shaft. This seal fills the circular area between the drive shaft and gear coupling.

See the “Shaft Drive” portion of the “Chassis” section of the Yamaha Service Manual.

Myth:

The forward end of the drive shaft moves within the universal joint.

Fact:

A compression spring is located at the final drive end of the drive shaft. This spring pushes the drive shaft forward toward the universal joint. If any front/back movement occurs along the drive shaft it occurs at the final drive end. Thus, the lubrication of the shaft's splined connection at the final drive is the most critical. Grease at the universal joint's splined connections is desirable for two reasons: inhibit rust formation on the splines and ensure that the splined connections don't become frozen and difficult/impossible to disconnect.

The drive shaft's rear splined connection has a large diameter and surface area. The torsional forces are spread over a large splined connection. Since this interface has the potential for movement lubrication is more critical here. Movement in this interface (if any) should be minimal. The center of the universal joint and the swingarm's pivot point appear to be in good alignment. So, the distance from the universal joint to the final drive probably doesn't vary as the swingarm moves up and down. A flexible dust seal on the drive shaft keeps dirt and moisture out of this critical splined connection.

Hmmmmmmmmmmm........... I've read a lot of posts over the past three years that said the oil lubed the splines at the pumkin. If what you say is true. these splines need to be regreased at some point. Anybody else want to verify this?

GP

Uhm...

the splines are MOST DEFINATLY NOT lubed by the final drive oil. The final drive oil only lubricates the ring and pinion gears.

These must be re-greased, usually when changing a rear tire.

The above post is pretty much spot on, and a great post!

All right then. I will check it at the next tire change. Hopefully all the other members of the forum that don't know this, will read the post. I'm assuming the shaft is not that difficult to remove from the pumkin.

GP

I'm assuming the shaft is not that difficult to remove from the pumkin.

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Not at all.....FJRTech.com.

Check Warchild's site for wheel removal as well.

The 06s are probably similiar...I guess.

Wait a minute. Unless I am very mistaken (wouldn't be the first time), you guys are all bonkers! :lol:

Whatever you want to call the rearward part of the driveshaft where it mates with the rear drive is most definitely lubed by the rear drive oil. That's what the oil is in there for in the first place. If you actually pull the shaft out of the pumpkin, or final drive housing, (as some have done accidently) it will be covered in final drive oil.

So what planet are you all from?

I'm assuming the shaft is not that difficult to remove from the pumkin.

Click to expand...

Not at all.....FJRTech.com.

Check Warchild's site for wheel removal as well.

The 06s are probably similiar...I guess.

Click to expand...

That FJRTech article has nothing about removing the driveshaft from the pumpkin. There is absolutely no reason to remove the shaft from the pumkin, and is NOT part of the maintenance procedure recommended around here.

Boy, oh boy, you started a mess Constant Mesh. This is all now clear as mud for the un-initiated.

Here's a photo of the rear (aft) end of the driveshaft where it mates with the final drive.

These gears are not greased! Final drive oil provides the lubrication!



And as I said above, there is no reason to pull the driveshaft out of the pumpkin.

Photo is from HMarc's outstanding www.fjr1300.info website.

So Constant Mesh, WTF are you speaking about above?

Uhm...

the splines are MOST DEFINATLY NOT lubed by the final drive oil. The final drive oil only lubricates the ring and pinion gears.

These must be re-greased, usually when changing a rear tire.

The above post is pretty much spot on, and a great post!

Click to expand...

Yeah, but Slap, the

The drive shaft's splined connection at the final drive is lubricated by gear oil.

Click to expand...

as Constant Mesh called them are the ring and pinion gears. Christ, terminology is getting us in trouble around here, and confusing everybody.

Constant Mesh's first "Myth" as stated above is incorrect, as the drive shaft's connection at the final drive, is as you say, ring and pinion gears, not SPLINES.

The splines (as referenced in the FJRTech article), are at the forward part of the driveshaft, and where the final drive connects to the rear wheel. NOT where the drive shaft connects to the final drive.

Aye Carrumba!!!!

I'm assuming the shaft is not that difficult to remove from the pumkin.

Click to expand...

No! Don't do that. We're talking taking the assembly out as a unit. It's the 4 acorn nuts and the unit comes out easily as a whole. Don't go ripping shafts out of any pumpkin.

Picture below: #1 are the splines...not the innards of the "pumpkin" that #5 generally points to.

I'm confused... was I right or wrong?

Is there a second set of splines at the rear of the shaft that are lubricated by the oil, or just the above pictured gears?

You are right SG, and I was ASSuming GPRider was talking about pulling the drive housing/pumpkin + shaft from the swingarm.

If you want to pull the shaft out of the final drive housing, that is different and messy.

:blink:

Inside the drive housing the gear oil lubes the final drive pinion gear and ring gear, as pictured above in SG's cutout picture.

Fact:The splined connections at both ends of the drive shaft are lubricated with lithium soap based grease or equivalent.

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Ok, I missed this bit the first time around.

I know there are splines on both sides of the U joint, but I only know of 1 set of splines on the driveshaft.

Dammit! Here I go again agreeing with skooter. This ****'s gotta stop! Can we re-open the break-in thread? :aacute:

Both ends of the driveshaft do have splines.

The rear of the shaft fits into the final drive shim, bearing and gear with splines.

Sorry the picture is so big....picture fixed

Ok, I get what Constant Mesh was after now. He is right, kinda, and I am partially wrong.

There are splines at the rear of the driveshaft before it then goes into the final drive, where it ends as a pinion gear.

For those with the service manual, look at page 4-104 for the exploded diagram.

I disagree with Constant Mesh that this portion needs to be lubricated. It is all pretty self-contained and sealed compared to the front of the driveshaft which is not sealed.

If you look at my photo above, I am talking about the "thick" part of the driveshaft at it's rear, before it ends at the pinion gear. To get this apart, and access the rear driveshaft splines, it looks like all you have to do is remove two circlips and the dust seal. Then the driveshaft will pull out of the gear coupling assembly.

Now I don't think this is necessary, but Constant Mesh may have a point.

EDIT: Damn, you just beat me to it FJRottie!

I am due for a spline lube. Assuming I get to it soon, I will pull apart the gear coupling assembly, and let you know what those splines look like after 63,000 miles of no attention. Will take pics too.

Ok, so now re-reading Constant Mesh's initial post. He is 100% correct. Just not real clear for all us laymen. Next time include a piccie!!!!!!

I am due for a spline lube.  Assuming I get to it soon, I will pull apart the gear coupling assembly, and let you know what those splines look like after 63,000 miles of no attention.  Will take pics too.

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Er, if the pinion is sitting in the drive oil and the shaft spline is turning the pinion, then they are in contact, right? Which means the splines are getting lube, right? There doesn't appear to be a seal of any sort between 'em...

Jes wonnerin'... :dntknw: