Rear drive issue

[Paul Carver]

On the way back from the Black Hills this week, my Avon Cobra developed a flat on the back with around 10,000 miles on it. Since that was my first Cobra I was hoping for a few more miles than that but that is not my problem. I told the service technician that I had been hearing a strange noise in the drive and to check it while he is in there. It turned out that the final drive flange and ring and pinion gear needed to be replaced. I have always made sure that the spline was greased at every tire change. Anyway, he told me that the tire should be pulled and the spline be greased every 5,000 miles ... in between tire changes.
Are you technical guys in agreement with this?? Some facts:

    * Interstate has 99,500 miles on it
    * Pulled a trailer for about 20,000
    * Replaced broken u-joint in Amarillo last year (beginning of the problem?)   

[Bagger John - #3785]

Honda doesn't specify a service interval for the final drive splines or mating parts in the service manual, and this is likely due to the fact that their OEM tires would last ~8,000 miles on average. With each tire change, you're instructed to remove the final-drive unit then clean, inspect and re-lube everything. Thus, the engineers assumed that proper lubrication of the parts would always occur.

Longer-lasting tires - especially car tires - change all that.

If you're running a high-mileage tire on the back...and put 8,000 miles or more per year on it...then a yearly removal of the drive unit, inspection of splines and re-lubrication is mandated. Replace "O"-rings and thrust washer (if worn) while you're in there.

[fast black]

There has been a lot of discussion about final drive issues.  I will tell you my experience.  My bike is 98 Standard with 73,000 miles. I am on my second car tire.  My final drive has little if any noticeable wear.  I am very particular  about how I reassemble bike after rear tire change.  I believe the most important aspect is to tighten the four fasteners on the swingarm after everything else has been  torqued. 
  I use stalube moly grease for the lubricant.  In fact I use that grease on all my drivetrain shafts, splines, etc.
I have never replaced an o-ring in the final drive either.  To each his own on that subject.
I am pretty sure you will get many more responses  on this matter, but this is what I have experienced.
I personally don't believe the final drive needs to be taken apart every five thousand miles and  have new lubricant  installed.  I check mine every 15000 or so and the splines always look fine.  I do it for peace of mind.  I clean and  replace  grease at that time as well (maybe overkill, but what the heck grease is cheap) and at every tire change.
good luck
fast black

[blkvlk777]

I put a flat on the center part of my avon a couple of years back and had to change it out prematurely.   I believe it is was my own fault after I found the air gage to be off by about 6 lbs psi off ( I was putting in 6 psi more than the recommended pressure).  After that, I am real skeptical of the air pressure gages I use but try to pay a few extra $$ for the nicer gages - although the one I bought was around $16 bucks.  Also I was assuming you were talking about a flat mark (circumfrence around tire) vs. tire out of air.  Hopefully it is something simple like a bad gauge? 

[fudgie]

I put a flat on the center part of my avon a couple of years back and had to change it out prematurely.   I believe it is was my own fault after I found the air gage to be off by about 6 lbs psi off ( I was putting in 6 psi more than the recommended pressure).  After that, I am real skeptical of the air pressure gages I use but try to pay a few extra $$ for the nicer gages - although the one I bought was around $16 bucks.  Also I was assuming you were talking about a flat mark (circumfrence around tire) vs. tire out of air.  Hopefully it is something simple like a bad gauge? 

I think most Valk tires get a flat spot in the center. All my Metz have had them. Esp when I went to a 200 size. Esp when you live in the flats with little twisties around.

[RTaz]

...there has been many comments about proper care for the final drives....I will give you my take on it and you guys can decide what you want... I find there are a few things that need to be done for proper care...agree or disagree ...okay...

1st...every time you pull your rear wheel off you should loosen the four bolts on the driveshaft...

2nd...when wheel is off make sure the o-ring and thrush washers are good ...o-ring wears from underside so it may look good but might be questionable...thrush washer feels flimsy when you pinch it between for finger and thumb then replace it...

3rd...on the splines and hub be generous with a MOLY PASTE...drive shaft and u-joints be generous with a MOLY GREASE

4th ....when you re-install the rear wheel tighten down the axle and everything ...THEN the last thing you do is tighten the 4 bolts for the drive shaft ...this will allow everything to realign it self properly...alot of people don't bother doing this and will say that it isn't necessary but since the manual say's it and since I was a die-setter for many years I believe this is very important....

[DeathWishBikerDude]

I've never messed with the 4 bolts on the final drive.
I did notice,the wheel rubbers/insulators are worn,and will be replaced at my next tire change.
Anyone replace their rubbers yet?
 
Increased vibration causing wear to the splines?
I grease mine often,and don't have much corrosion,but don't waant any future headaches.
I guess 100,000 miles on the originals,is not bad anyway.