Blew up the driveshaft?

[groupus]

https://imgur.com/a/fhLLlhl
https://imgur.com/a/qR3m4mr

Surprise! None of the above. The GL1000 is poorly designed so that grease from the zerk fitting does not get to the splines in this cup to the rear end. My plan and suggestion to all is to take the three bolts off for the rear end and lube this spline every other rear tire change.

[groupus]

20230829_194012.jpg (173.14 KiB) Viewed 338 times

[groupus]

20230829_194031.jpg (199.31 KiB) Viewed 336 times

[gltriker]

edit

removed content I had found interesting

[redglbx]

This is a common failure, the grease zerk does nothing but make you think you did something. If you look closely you’ll notice that there is a shield just under the zerk that deflects all the grease you pump into it onto the outside of the driveshaft where it does nothing at all.

To prevent this from happening again you need to use a high moly content grease and liberally slather it on all the splines at EVERY tire change, nothing less ! Don’t trust the dealership will do this !

When I bought my 76 new, one of the things that I liked about the 76 model is the “update” Honda did by adding the grease zerk to supposedly fix a problem they found on high mileage 75’s.

I remember telling my buddy who was the tech guy for the CWC about how great it was that Honda added that zerk to fix the spline problem and then him laughing hesterically at me about it while asking me if I ever looked at it to see the deflector ?

Anyway this is a common problem on all shaft drive bikes that is caused by the vibration (fretting) between the splines, none seem to be immune. Grease all the splines at every tire change and use a good Moly grease like the Honda Moly 60 paste. My .02

[dontwantapickle]

I'm not convinced that this is really all that common of a failure.

Now, I ain't no expert,
but with 45 years of dealing with goldwings (over 300,000 miles ridden), I have never seen these splines destroyed before.
Obviously, the pics show that it can happen, so a bit of grease on these splines isn't a bad idea.

Like redglbx said: that grease zerk does nothing.

[redglbx]

Don, over the years I have seen this a number of times on other peoples bikes but never on any that had been greased. Not only the driveshaft splines but the drive splines as well. I agree that it’s probably not a “common” failure but it’s not uncommon particularly if the splines never get greased.

Fretting is the real problem which is the rusty powder that is common on these that haven’t been greased, the grease is more about cushioning the splines than actually lubing them.

[gltriker]

Next time you have one of these sliding spline pinion couplers exposed, take a close look at the side profile of the male splines component.
I first time noticed, when building my less than 10000 miles 1980 CB900 Custom trike, after removing the generous quantity of grease from the male pinion ,
there was a slight radius apparent in its spline side profile. Interesting.
Although I never closely examined the well lubricated sliding spline coupler on my less than 8000 miles '75 GL1000 during its trikification project I briefly wondered how much to and fro distance the male and female splines entertained when the rear suspension was compressing and rebounding .
There must be a small amount of 'driveshaft' longitudinal oscillation created as the motorcycle is moving along when the u-joint is doing its job as the swingarm pivots, ' up and down.
Sliding friction in that constant contact connection too.. just thinking


A few minutes after I posted this long winded composition I wondered how and why this less than 8000 miles 1975 GL1000 was found by me to be have been adequately lubricated. No grease zerk.
Aha!
Must have been a proactive inspection revealed the need for additional grease in that sliding spline area when the new rear Lester wheel was installed

[groupus]

I'm annoyed that this maintenance isn't promoted more. I've never read about it or had it suggested until now (even that is digging down through a topic on a trike build as gltriker suggested). This is maintenance that should be a sticky or suggested to every newbie rider the same as timing belts, especially if the splines should be greased every tire change. I've read to clean and grease the final drive splines connecting to the wheel, which I do, but not this.
My bike is a full touring 79 with 63,000 mi on it. It sat for a long time before I got it in 2015, and has been a daily driver across country tour since. I did a lot of the specified maintenance recommended on this site and others (i.e. randakk's starting a bike after a long day up) and then some. I'm just annoyed because these are supposed to be low maintenance driver trains, and I always thought I took really good care of my vehicles.
Anyway, rant over. I have new / used parts ordered. I rode my other GL1000 to work today and all I could think about was those splines grinding to dust. I'll be ripping it apart asap now too.

[gltriker]

Oooops double posted next one down

[gltriker]

Good man
You can pack the female sliding spline coupler full of grease while you're at it.
No, 'excessive' grease won't hydraulically bother the final drive pinion shaft lip seal.
The ' extra ' grease will purge past the lip seal that surrounds the female coupler. Grease can also purge past the snapring and the hidden splines.
Notice the opposite side slots on the hidden end of the female coupler? That's the exit point.

Regarding, the Rant. Hmmm
a bit too much chiding there is my lasting impression

Okay.
Now... it's your sworn appointment/obligation/duty to insist before new owner start up, the proactive out-of-sight sliding splines lubrication maintenance, like timing belts replacement, is a must do, too!

Go get 'em!