Shaft Failure. Which part again? Have microfische shots.

[Redman]

A few weeks ago there was discussion about shaft failures. Several of you great guys gave great information. Was discussion about what lube to use. Was discussion about design change to gears?splines? in 82?83?. SOme said failure is inevetable, others said no problem if lubed well/properly.

Since then I have printed out pages of the microfische I have. Looks like the "final gear" is part of the rear drive unit. And the "joint assmby" is part of the rear wheel. I have seen that "joint assmby" (or "wheel spline" I gather) when have taken off rear wheel, That and its mateing splines (on back side of "final gear") is what I have lubed when I have changed the tire.

My question is this:
Again, WHich part is it that is subject to failure if not lubed? Or another way to ask this: Of the parts I may find on Ebay, do I want to get a rear wheel or a rear drive unit if I want to have a spare on hand? Or both?

Here are scans of the microfische:
Page H5, Rear Wheel


Page D10, Final Drive

Later edit: Made smaller images, only about 50K each.

[sv650]

No-lube failure

In the diagram you have posted, the most likely part to fail due to lack of lubrication is the part numbered 1 on the second diagram. The pinion gear (on the shaft) usually is damaged first, because of its smaller diameter, However the ring gear can be damaged by the removal of a few teeth at one point, then (if forced) spread further, as the teeth grind against one another, making a real mess. I totally stripped the front differential on my truck on a highway trip one winter. The inside to eh the case did not look pretty; neither did my credit card......

So, if you are looking on e-bay, you want to buy the differential case -- the large silver piece that sits to the left of the rear wheel, and accepts the driveshaft.


SV

[argonsagas]

Looks like it would be sheet D-10, part 15.

Nothing difficult to determine in real life, however. No disassembly of any of the gear train needed, just removal of the rear wheel from the bike, as you would do when changing a tire.

When your rear wheel is OFF, you can see the driven splines.

Grease them.

[Redman]

Opps, in my original posting I had the pics labeled wrong, sorry for the confusion. I just fixed that, and made the pics smaller so doesnt require so long to load.

Thanks for the comments and shared experience.

From these and other comments, it seems that what Zuki lables as one part as the "final drive gears" (Part 1, sheet D10 &D9) are what is commonly refered to seperatly as the bevel ring gear and the pinion gear. These are inside the gear unit are in the gear oil.

And what is commonly called the "splines" are on two differernt parts. One splines on the Joint assmbly (part 15, sheet H5) shown on the wheel. And the mateing spline is on the back side of the bevel gear. Both can be seen when wheel removed, and both are what I have lubed/greased when I have removed the wheel to replace the tire.

My understanding from previous discussion is that it is these "splines" that typically fail if not lubed/greased well. Most people know to keep gear oil in the gear unit but may not grease these splines.

So now this posting is to ask: If I wanted to have a spare on hand, should I get a spare gear unit or a spare wheel?

A couple of weeks ago a few others (daveo, jimcor, dpep, Focus Leon, b'ringer) had comments also. I welcome any further comments.

[focus frenzy]

Looks like it would be sheet D-10, part 15.

Nothing difficult to determine in real life, however. No disassembly of any of the gear train needed, just removal of the rear wheel from the bike, as you would do when changing a tire.

When your rear wheel is OFF, you can see the driven splines.

Grease them.

part 15 on sheet H5
from my understanding of the issue, you can use the adapter from a earlyer bike, they don't have the problem.
I have put 30K+ miles on my high milage 1000G and my splines show no real signs of excessive wear and the bike has over 134K miles on it.

[Redman]

Thanks Focus Frenzy Leon and a'gas,
If Leon has 130 some thousand on his 80 GS1000 and no problem with the splines on wheel joint assmbly/adapter, and the splines on the final drive bevel gear, then I am going to say that I need not bother to get a spare for my 80 GS850G (60 thousand). Especially since I have been lubing these splines on occassion of tire change. And other previous postings say its the 83s and later that have problem with the splines failing if not lubed well. Sometimes will see comments about "every shaft will fail", I am deciding to discount those.

Thanks guys,
DAVE "REDMAN"

[daveo]

Thanks Focus Frenzy Leon and a'gas,
If Leon has 130 some thousand on his 80 GS1000 and no problem with the splines on wheel joint assmbly/adapter, and the splines on the final drive bevel gear, then I am going to say that I need not bother to get a spare for my 80 GS850G (60 thousand). Especially since I have been lubing these splines on occassion of tire change. And other previous postings say its the 83s and later that have problem with the splines failing if not lubed well. Sometimes will see comments about "every shaft will fail", I am deciding to discount those.

Thanks guys,
DAVE "REDMAN"

Hey Dave,
my understanding is that (like you said) the 83 and up, splined hub (H5 -15) is the part to fail, by design, as opposed to the splined side of the bevel gear (D10-1), so if you have an older rim, pre-'83, I'd want to switch to the newer, softer rim/hub, which is cheaper to replace than the ring(bevel) and pinion set, which you should otherwise have no problem with as long as your gear lube level is good. Of course, since you've always kept the splines lubed, it may be a complete non-issue for you, just always use a high pressure/hi-temp grease. My experience is that ,when well maintained, the truly 1st things to fail, are the seals themselves........a thunk

[SqDancerLynn1]

It depends If you are like me I have quite a collection of spare parts! The spline joint assembly can be found on ebay if you look, I got a super deal on one last month from ebay.

[Planecrazy]

What's a super deal, Lynn? In other words, what should one expect to pay for these parts? I have an '82 GS1100G parts bike (which I assume has the stonger splines), and I've already taken the final drive assembly off (lucky me) to save as a spare for my '83. By the way, should I also take the mating splines off the wheel and save those before selling off the rest of the bike?

Thanks in advance!
Steve 8)

[SqDancerLynn1]

I paid $10 + $10 shipping, it lists for $114 on BB. You may never need it?
But I would keep it for a spare

[Giblet]

The origin

The origin of Dave's c oncern was my 82 GS1100GK. The hub adapter splines failed (stripped). I am replecing it with one off of an 80 GS1100G. The casting definately appears to be different materials. 82 appears to be clear zinc plating while the 80 has none. I think mine was caused by non-lube. This bike was my first shaft drive and when I replaced the rear tire the splines were clean/dry so I just assumed that was how they were supposed to be. We all know what assuming will do for you . Why I didn't think it strange that I lube the splines where the front & rear shafts come together on my '00 Sierra but not on the bike is beyond me :? .

:roll: Oh yeah. my understanding is that the 81 and back have the harder material in the hub adapter. My guess is that if you (I) keep it lubed regularly you'll have no problem. Going to try to pick up a spare hub adapter for ling trips. I think could have fixed it on the road had I had the part. About 5 miles from Leakey, Tx, hillcountry.

[gs650gt]

part 15 on sheet H5

I agree. In my GS650Gt that part (the splines actually) was worn out at 160 000 kms. I luckily found a used spare part and have driven 60 000 happy kms with it.

I would have changed the other part too but it couldn't be found.

[bwringer]

The "joint assy" (the part #15 on the wheel) is the part that's designed to fail first.

When mine failed, there was some visible wear around the edges of the teeth on the mating spline on the gearbox, but it was perfectly usable. I dropped in another I bought for $15 or so from eBay and used it for a while with no problems. A few months later, I scored a flawless "joint assy" and gearbox from an earlier model GS850 with very few miles and installed those.

The earlier one is a darker metal and does have a better reputation for durability.

A new one is just $81.24 from http://www.crotchrocket.com

That's a lot cheaper than a new chain and sprockets!

Normally, people just sell the whole rear wheel on eBay, but you do need to ask or see a picture to make sure the spline dealy still there and in good condition.

And I hear that you should use black, smelly moly grease, not just regular brown grease.

[Giblet]

I ended up with a whole rear wheel assembly also but from a salvage yard $50. The wheel is a 17" which I can't use as I am looking to drop the rear on mine an inch if I can to compensate for my short legs. Any market for a rear wheel off an 80 model GS1000G? Weathered Dunlop included, w/o hub assy adapter :roll: .

PS. Removed two of the studs from old adapter and am using it as a stand to hold PWB's while I instrument for thermal testing. DO THAT WITH A CHAIN & SPROCKET.