Final Drive Mystery

[X Ring]

Rode the 90 miles to my buddy Chuck's house today.  When I got there he did somehting strange.  He knelt down and put is hand on my final drive of Sandman, my 97 Tourer.  I was looking at him like he was  .  When he got up he told me the final drive on his 2K I/S gets extremely hot.  I know it is well maintained.  He's almost as anal as Punisher.  He uses Bel Ray grease on the final drive and wheel flange splines.  In the pinion cup he uses a mixture of TS 70 with assembly lube mixed in plus the Bel Ray.

After my final drive cooled down we went on a 25 mile ride.  When we got back, I touched my final drive and could hold my hand there for 15 seconds.  I touched his and about 5 seconds was about all I could stand.  In addition, I couldn't keep my hand on the pinion cup area because it was so hot.  Mine was warm but nothing like his. 

We both use Valvoline Synthetic gear oil.  I fill mine while my Valk is vertical on my jack and he fills his on the sidestand.  Sandman has about 46K miles while his I/S has 62K.  Only thing I could come up with is he may have overfilled the pumpkin and the oil can't move in and out of the pinion cup.  In addition, the Bel Ray may not dissipate heat as well as the Valvoline Synthetic Disc Brake Wheel Bearing grease I used in the pinion cup.  I use Moly 60 on the final drive and wheel flange splines.

When I left he had put his I/S on the jack and was going to rip the final drive out and inspect it to make sure the gear oil was being pumped into the pinion cup area.

Anybody have any ideas? 

Marty     

[Robert]

The pinion cup is not lubricated by the holes although you would think maybe. The level in the rear has to be allot higher to get into the cup with any meaning full amount to be effective as a lube and if it did that it would wash the grease away. If you really think about it how is 5 oz of lube in the rear going to lube the pinion cup for say 25k miles? You would in short run out of lube in the rear or the pinon. As for the temp to be able to hold your hand there for a few seconds comfortably should be the case. I can put my hand on my final drive and hold it there no problem I use the Mobil one 75/140 or the Red Line 75/140 and its comfortable to the touch. I would think that the lubes you guys are using is ok because I also use the Belray with no problem. If there is no noises I really wouldn't worry about it just yet,maybe the pinion bearing is a bit tight since the heat is in the front of the diff. Diffs do get quite hot on cars.

[Tundra]

I'm just guessing here, no flaming arrows please. Maybe, just maybe someone did not use the proper torquing sequence of the driveshaft and axle nut while re-assembling, possibly causing more friction or wear on the splines, inturn causing more heat?  Possibly??

[X Ring]

Thanks Robert and Tundra.  I'll agree it's possible but doubtful.  Iirc, he's the one who stressed the importance of loosening the final drive nuts then tightening them last when I first got Sandman three years ago.  We're looking for any answer to explain this other than it's just another Valk idiosyncrasy.

Marty

[MP]

A lot of us will disagree with you Robert.  I, and others, believe the holes ARE to lube the pinion cup.  Use assembly amount of grease on the pinion cup, then the oiling is taken over by the rear end lube.  There is oil mist in the rear end that lubes, the level does not need to be up to the holes to lube.  If the holes are plugged by excess grease, they will not get lubed then.

When I take mine apart, it is well lubed with rear end oil.  Very nice shape.

MP

[Warlock]

A lot of us will disagree with you Robert.  I, and others, believe the holes ARE to lube the pinion cup.  Use assembly amount of grease on the pinion cup, then the oiling is taken over by the rear end lube.  There is oil mist in the rear end that lubes, the level does not need to be up to the holes to lube.  If the holes are plugged by excess grease, they will not get lubed then.

When I take mine apart, it is well lubed with rear end oil.  Very nice shape.

MP

I clean mine very well everytime I inspect and regrease the rear end. I still use a little grease in the pinion cup, but I make sure the holes are open before install it back together. I believe a little oil gets up there. I do know if you use too much grease and stop the holes up your putting yourself up to possible messed up pinion joint and drive shaft.

[Jeff K]

The pinion cup is not lubricated by the holes although you would think maybe. The level in the rear has to be allot higher to get into the cup with any meaning full amount to be effective as a lube and if it did that it would wash the grease away. If you really think about it how is 5 oz of lube in the rear going to lube the pinion cup for say 25k miles? You would in short run out of lube in the rear or the pinon. As for the temp to be able to hold your hand there for a few seconds comfortably should be the case. I can put my hand on my final drive and hold it there no problem I use the Mobil one 75/140 or the Red Line 75/140 and its comfortable to the touch. I would think that the lubes you guys are using is ok because I also use the Belray with no problem. If there is no noises I really wouldn't worry about it just yet,maybe the pinion bearing is a bit tight since the heat is in the front of the diff. Diffs do get quite hot on cars.

I'm with you on this one. I pack my cup and shaft with grease and in 120,000 miles I've never have any problem with the pinion. I believe those holes are there to vent.

I have a spare swing arm with the final drive and wheel on it. I've been tempted to rig it up so I can roll the wheel and watch to see what happens in the pinion cup. But, why bother, there would be a way to discredit any "test" and I don't really care since what I have been doing has been working fine for me for 11 years. But it still might be fun to try.

[98valk]

 and he fills his on the sidestand. 
Anybody have any ideas? 

Marty     

this will cause an overfill condtion, which can lead to aeration and foaming of the oil.
Air is a poor lubricate.

[Chrisj CMA]

 and he fills his on the sidestand. 
Anybody have any ideas? 

Marty     

this will cause an overfill condtion, which can lead to aeration and foaming of the oil.
Air is a poor lubricate.

Will cause overfill ONLY if he fills to overflow on sidestand.  I fill on sidestand sometimes.......but I just pour in 150cc and none leaks out or overflows and that is a neat way to do it

[X Ring]

He filled to overflow.  Chuck called me this morning and told me he pulled the final drive.  There is no evidence of oil entering the pinion cup in the 150 miles since he last serviced it.  Chuck also told me when he tore it down the last time it didn't look like oil was getting into the pinion cup.  Chuck rode his Tourer to work this morning.  When he got there, he felt the final drive and it was warm like mine was yesterday but not burning hot like his I/S.

Marty

[Tundra]

Best of luck, please let us know the outcome. I'm real curious now, shoot something else for me to check

[X Ring]

I'm tempted to bring a infrared temperature gun to Cheaha and check as many punkins as I can.  As heat is a by product of friction, maybe we can figure out if it's a sign of the pinion cup or final drive going out.

Marty

[fudgie]

I've never had oil in my pinion cup. Everytime I pull it its dry. I use a needle to clean the hole each time also. Always very dry. If oil does get up there, what keeps it from coming out of the cup and running out to the road? Its not sealed. X, I use the Valvoline moly grease on mine also. Never have felt my rear end after a ride, well, the bikes.  ???

Maybe someone can tear one way down and see if oil does get up into the cup.

[X Ring]

Just talked with Chuck.  He drained the oil out of the punkin and it was about 6.2 oz.  It did have a bluish green tint to it so that indicates some of the Bel Ray ended up in the final drive.  I'm wondering if the extra weight and airflow characteristics of the I/S keep the air from cooling the final drive as effectively as the Tourers.  Now I wonder if the Standards run even cooler.

Marty

ETC my goof on the oil amount.

[98valk]

per tech manual  - after draining 150cc (5.1 oz)
                           - at disassembly  170cc (5.7 oz)

[Robert]

I have had the rear off so many times I was thinking about putting a quick release. But really I have tried many variations just to see what will pan out. When I first took mine apart for the first time there was no grease and a little rust. I wondered how hard could this be so I used wheel bearing grease and assembled the whole thing. Well first attempt was ok but not great.  I tried some of the most expensive grease out there trying to conform to the Honda specs for a graphite grease. By the way why if the holes are for lubrication would Honda use a grease on the splines as well as on assembly tell you to pack the pinon seal with grease? Well the Krytox alone with normal oil level was ng, Krytox with a high oil level ng did exactly what I thought washed the grease away when the rear oil hit it. So bad so that it started to rust and started to wear the splines. So lets try just the rear oil idea ng even with a high oil level full when on the side stand. So by this time I was really thinking what am I going to do and be happy with so I tried the Belray and upon inspection it was  perfect and I packed the pinion cup. This did the trick and through these times I was using a Mobil One 90w gear oil with ok results. The other thing I did not mention since the issue was rusting I thought that somehow water may be getting into the driveshaft and causing problems so I do seal the joint where the four nuts hold the rear on with silicon and I have also sealed up the extra holes in the swingarm. Sounds like I have to much time on my hands but I hate this kind of stuff especially when I like to fix something once and not think about it. What I have concluded is the Belray with the 75w/140 is the best combo. The rear end oil I also tested with Lucas lube and not really happy with it either. I did find that it did keep the rear a bit warmer than what I think it should have been. I also installed a magnetic drain plug with a super strong magnet for the rear and the engine oil drain to help remove any little bits of contaminant. My diff runs cool and the splines do well no rust and no wear. If you can get a pic of the rear I was going to post one but keep getting the site attack thing you will see that the bearing rides pretty much on the holes and with the pinon assembly there is no provision to let the oil through with any deliberate engineering. I also believe that with the lack of grease there is quite a bit of heat build up and this heats the pinion cup and splines as witnessed Honda calling for extreme pressure grease and when these heat up and cool down condensation appears on the assembly. Like when you heat metal and when it cools it rusts dosent take all that much heat brake rotor hubs are a great example. So when you start using your bike again this cycle keeps happening till the point you are grinding rust as a flour mill would grind flower by that time the splines are well on their way to being toast. Hope I didn't bore anyone but tinkering is kinda fun and I do like my Bike to run well and get a system down on maintence that all I have to do is follow the program and its done. for all those that worry about to much oil dont it will run out and not really make a difference just dont try to fill it to the top. I do mine on my side stand because its easy and just fill a little below the hole and there's no problems. 

[Wildman]

You have maintained your reea splines and drive shaft coupling, and it sounds like you have, it is very unlikely that they are producing very much heat. the right angle drive does consume power and that shows up as heat it is the pumkin lube that needs to be right.
I also fill my pumkin with the bike on the side stand. I ve never had a problem and it does not get hot. I use mobile 1 75W140 fully synthetic. if the heat was form bad alignment of the drive splines  or l;ack ofg lube on the shaft coupling they would be wearing at a very quick rate.

[Misfit]

I've never had oil in my pinion cup. Everytime I pull it its dry. I use a needle to clean the hole each time also. Always very dry. If oil does get up there, what keeps it from coming out of the cup and running out to the road? Its not sealed. X, I use the Valvoline moly grease on mine also. Never have felt my rear end after a ride, well, the bikes.  ???

Maybe someone can tear one way down and see if oil does get up into the cup.

Next time you tear it down you will notice a seal on the drive shaft. This keeps the oil/grease in and the water and dirt out.