Another spline lube thread

[F14CRAZY]

After about 15k miles (arguably too long) I decided to remove my final drive to lube the splines. This is what it looked like after about a year and 15k miles with a gob of Honda Moly 60 applied:



Splines are bone dry and even look rusty. I don't think water is getting in there but obviously Moly 60 isn't doing shyt at this point.

There are way too many different opinions on what grease to use, what grease to blend another grease with, using anti seize, moly, etc etc. I googled and found someone suggesting Lucas Red n Tacky grease:

http://lucasoil.com/products/grease/red-n-tacky-grease

says it's good for sliding surfaces, and to my splines count. At any rate I had the bike apart and had to put some kind of lubricant back on the splines. I figure applying Honda Moly 60, at least straight from the tube, is a waste of time. I've read of others reporting that their splines looked dry a while after using Moly 60...aaaand it happened to me too.

Is molybdenum disulfide really what we have to be using?

I can always order some Guard Dog Moly and re-lube but I might as well run this Lucas stuff and see what it looks like when my rear tire needs to be changed out again.

[Motorhobo]

IMHO the issue with the lubless splines has less to do with the protective qualities of Honda Moly and more to do with the 15k service interval :-)

If you really want to test the qualities of a lube product, wouldn't it make more sense to do the lube at the recommended interval? I don't think there's any product that can last 15k miles.  I don't know if there's an equally effective alteernative to molybdenum disulphide, but didn't rbm recenntly quote the manual in another thread that specified 50-70% moly?  Seems it would be best to stick with the engineer's recommendations, especially since GD is so cheap and just a little quantity lasts for years and years.

My $0.02...

[TimTyler]

I don't think 15k miles is unreasonable. I've heard "lube at every other tire change" from respectable K-owners and that works out to about 20k miles per lube.

I've used the same tube of Castrol Optimol Paste TA for the last 60k miles and I've never seen my splines look dry.

[Motorhobo]

That's news to me. I thought you were supposed to lube the final drive splines every tire change or 6-8k miles. That's what I read here and that's what I've been doing, especially considering the crappy condition of my FD splines. I thought it was the clutch splines that need it every 15k. I guess i figure if I have the tire off, what the hell, it's not too much work to pull the FD, so I'll probably keep doing it at that interval.

I agree with F14CRAZY that Honda Moly 60 is too thin and seem to disappear, though. I didn't know Castrol was an acceptable alternative to moly paste. But I guess the question is, just because it's wet does that mean it's doing the job as well as a moly grease?  Wwhy would BMW engineers specify the use of moly compound grease if it wasn't the best material for this application?

[TimTyler]

The Castrol TA stuff was what BMW was recommending for splines a few years ago. That's what my dealer said, at least. It was the only spline lube they stocked.

[rbm]

20,000 km is the figure I've read regarding the frequency.  It's not unusual to see the dryness of the splines after the Honda moly application.  The soap-based carrier in Honda Moly60 will be quickly flung off in use, around the final drive housing and inside the drive shaft, in a very short time.  The active ingredient, the Molybdenum Sulphide, imbeds into the steel and continues to work. Anything you can do to prevent the carrier from disappearing rapidly will add time to the process of absorbing the moly.  Therefore, Guard Dog has a thicker carrier that inhibits this.  Similarly, mixing your favourite moly paste with a very high viscosity carrier like Wurth SIG 3000 Spline Grease will accomplish the same thing.  That's what I do -- use a 50/50 mix of Honda and Wurth products.  The stuff is like melted Mozzarella cheese, all stringy and gluey.  And it sticks to anything so handling it cleanly is challenging, but it works great.

Honda Moly60 is no longer in production and its substitute is Honda M-77 assembly lube.

[K75RT Keith]

Is molybdenum disulfide really what we have to be using?  No, But finding a lube that is a 50 - 70%Titanium disulphide tends to be expensive.

If you wipe the splines down and you'll find it isn't rust, it's moly.

There is a thread that discusses how teh movement of the coupling works the lube out and off the splines.  That's part of the reason they recommend the use of a high molybdenum disulfide lube.   

[F14CRAZY]

After 5251 miles I removed the final drive to see how the Lucas did. There was still some on the splines but a lot of bare metal.

You guys convinced me that the rust that like Moly 60 leaves is the moly itself.

Since that stuff is made for this application, and enough of us use it, I cleaned it up and applied Moly 60 again.

It seems weird how the splines on the final drive end of the driveshaft wear more than the trans output shaft splines. The trans output looks new while there's a some mountaining of the final drive end. Final drive end has some mountaining but not bad.

[rbm]

Not weird; it's physics.  Read:

http://www.motobrick.com/index.php/topic,490.0.html
http://www.largiader.com/paralever/

The final drive is moving up and down with the suspension and the splines are sliding between each other.  The final output shaft is capturing the drive shaft with a circlip so the splines are not sliding between each other.  Both are experiencing rotational acceleration and deceleration with each revolution though.