Final Drive

[MikeS]

I first registered on GSResources years ago when I had my '79 GS850G. I let long periods go by between posting and I think the board went through some changes since, when the head gasket failed at 75K (mas o menos, can't recall exactly) I bought a showroom condition '82 and went onto GSResources to share the good news. I couldn't find any of my old posts or any record that I had ever been registered. So I registered again. This would have been 2008. Upon getting back onto the forums, tirst thing I heard about regarding my new '82 is how doomed I was to being stranded when the gold wheel driven-gear inevitibly failed. I considered just changing out that gear, using the one on my old '79, but never got around to it. Based upon the strong opinions and suggestions regarding the gold metal gear, I was expecting, those first years, to have to do this at any moment. I remember one poster who was adamant on this issue . . . that the failure of that gear was certain and soon.


At my first rear tire change I took and posted pictures of that gear and it did show a little wear. One GS'r pointed out the small degree of wear that was showing and predicted it was well on its way to failure. That picture(s) and my other posts from that period disappeared with time along with my second membership on GSResources so I re-registered for the third time in September of last year. I'll look in some camera folders and see if I can't find the picture of the splines taken at that first tire change and re-post it.

At the time of that first tire change my tire guy just used normal axle grease. Second tire change, approximately 7K miles later, I brought him some moly grease but it wasn't the really good stuff I've since learned about on these forums.


Today was my third rear tire change and my tire guy said he found no additional wear since the last time he had the wheel off. Again I brought him some moly grease (but still not the good stuff). I'll get some by the next tire change. I didn't take a picture today since I dropped the bike off and wasn't around when he did the wheel, but I have talked to him about my concern with the gold metal driven gear in the wheel and reminded him today to please take a close look at things.


So here's the stats: It had 17K when I got the '82 and today it has 34K. I'd guess 80% - 85% of my driving is daily up and down through-the-gears driving. Urban, side street stop & go heavy acceleration. I'm guessing this would be more stressful to the gears than steady-state freeway driving.

My '82 had 17K miles when I got it and today, when I put my third rear tire on, it has 34K. Tire guy says it's showing no additional wear. His theory regarding the failures is that when these bikes came from the factory they had a light vaseline-like coating of gear grease. He supposes that many new final drives did not get re-lubricated when it came time to put a new tire on so a wear pattern got well established thanks to inept maintenance. Because the gears did not have an abundance of grease from the factory , some tire changers may have assumed it didn't need much. Many may have just forgot to lubricate the gears, especially if pressed for time. Just a guess on his part, but if the gold metal is indeed weaker than the silver or black metal, any lack of lubrication may have pushed it over the edge and led to early failure. The black and silver metal gears may be able to hold up better to lack of good lubrication.

It appears in my experience so far that with good lubrication the gold gear holds up fine. I'll report back in another 7K miles when I again have the wheel off (unless I get a flat in the meantime).


Mike
'79 GS850G - parts bike
'82 GS850G - daily driver

[tom203]

Might depend on driving techniques, but stuff about gold splines seems based on member's experience. My 81 gs650 spline looked surprising good at 43k-I lubed it at tire change , hoping it will outlast me!
if you don't post occasionally, you get dumped! Check in more often- I'm sure you can offer help/opinions to others.

[LarryJ]

On my '82 1100GK (powerful & heavy), I had to replace both the rear spline & the clutch hub nut. Both are metallurgical weak points. I got the bike about three years ago, with 23K on the clock. The clutch hub was already rattling then , & the wheel spline went within 500 miles of getting it running well.
Like some have suggested, I bought a whole 850 rear wheel, on eBay, for $40 including the spline. I wanted to eventually convert to a 17" rear wheel anyway.
In 7K miles since then, I have seen no wear on my black spline.I always use a molybdenum grease too.

[Grimly]

My '79 (140K) and my '80 (250K) both show no spline wear at all. Both on their original rear drive units, too.
Having said that, there's now a fair bit of backlash on the '80 unit - so might need rebuilt / replaced in the next couple of years.
I was a bit hacked off to find a spare wheel I bought recently came with a gold-coloured spline - and it's well worn, enough to be scrapped.

[chef1366]

I have one off an 80 GS1000G if it will fit.

[GSLove]

Hi This is my first post to the GS Forums and I was wondering if anyone has any knowledge about using different final drives from different years. I have an 82 GS1100GKZ and when I took the back end apart I noticed that my final gear was in terrible shape, so I am trying to find a good replacement.

I did find a decent one on E-bay from a 79 850, but I don't know if the 79 850 will fit my 82. For information my bike has a 17" rim vs the stock 16".

Final Gear 27300-45811.jpg
This is what the final gear looks like on the differential side and the wheel side looks about the same, terrible! Only 84K on the bike.

[phydeauxmutt]

Splines will be the same. Not sure about the 450GA and 650G units, but the splines from the '79 850 all the way through the 2017 Boulevard series are all the same part number. Just try to avoid the '82 units, which have a gold appearance, like yours.

Actually, taking another look at your picture, you have the drive splines in the final drive unit pictured. What usually fails is the driven splines in the wheel. Those are a lot easier to replace. You will want to check those out, too.

The final drive unit itself is a bolt-on replacement for 850, 1000 and 1100, but the '83 units have a slightly taller ratio, 2.9 vs 3.1, which will lower your revs slightly.

[Nessism]

The photo shows the actual final drive unit. Those units are typically very robust and last the life of the bike. The splines are supposed to be lubed with heavy moly grease. The wear suggests that this detail was overlooked though. Sadly this is all too common; many people practice the FUF (forget until failure) approach to maintenance.

The final drive units for the bigger 850/1000/1100 bikes all interchange, in fact, they identical other than (as mentioned), for 1983+ the gearset inside the housing is a taller ratio. Since your bike is an '82 that won't be a concern though, unless you want to try the taller ratio unit on your bike. The final drive splines never changed over the years, it was the driven spline in the rear wheel that did. The early splines were black and very robust. Starting in something like '81 though Suzuki used a different heat treatment process and those splines fail. Even when they do though they rarely wear out the splines in the final drive unit though. At any rate, if your rear spline in the rear wheel is goldish colored I'd just replace it straight away, along with the final drive. Final drives are dime a dozen on ebay, in fact it costs more to ship the thing than purchase it.

Good luck

[GSLove]

Thank you for all the great advice you guys are awesome! The spline in the rear wheel is definitely finished as well, so that will need replacing. I was going to check the availability of the rear wheel spline from my local parts supplier who is currently listing it for a price of $211 CAD according to the parts fiche.

Rear Wheel Spline.jpg

[kochic]

I have few black drive spline, just PM me.
I'm in canada too.
Marc

[GSLove]

Thanks Marc, PM sent!

[Nessism]

The black 850 driven splines are good ones. Exception being the very early type that were recalled. Those use separate bolts as I recall and the casting is not as robust as the later type.

[GSLove]

New final drive and mating wheel drive on the way. Final drive from an 80 GS1000 and the mating drive from a Suzuki VS800GL. Well see how everything fits together, fingers crossed!

[GSLove]

I just received the wheel side of the final drive today and I was wondering if the height difference (roughly .1875" or 3/16") from my old one compared to the one I received matters?
The part number that I purchased was 64680-45113 which apparently replaces 64680-45112 (originally on my bike). The only difference is the height because as you can see it fits perfectly in place and the spline line up as they should.

Compare.jpg

[kochic]

This is the part suzuki send you when you order a drive flange.It fit all drive shaft bike from 1979 to 2017.

Marc