Rear end work caused new rear end sounds?

So, I got some plastic surgery........kidding, kidding

I pulled off my rear wheel -- after reading enough about how simple it was -- to check the rear shoes and general condition of the hub. What I found was.....not surprising considering what I found when I pulled off the seat to run some new wiring for the new horns I'm installing. In the fusebox/nook&crannies I found cobwebs, dead spiders, spider egg nests...just everywhere. It was gross.

















The castle nut lost the cotter pin - I didn't event have to break it free, it was basically hand tight! I found a piece of metal to run in the axle hole end on the right side. That slipped out without fuss. Then I disconnected the brake line, and the secondary arm and rolled the tire out.

With the tire off, I decided to change my final drive fluid -- it came out looking like thick chocolate milk.... absolutely awful.

I poured in new Valvoline DuraBlend (Synthetic Blend) 75W-140W.
I've read posts going both ways on 80-90, 75-90, 75-140. At the end of it, I made sure it was a valid GL-4 oil (not sure if that's supposed to be the type or rating -- but it was listed as GL-4 and GL-5)

edited: GP to GL

If anyone has solid proof that running that is bad -- I'm open to suggestions to switch to 80-90W.

So, while I was waiting for the oil to drain, I decided a quick cleanup of the hub was in order. I whipped out the brakekleen, only to stop in realization that its a degreaser and spraying it anywhere near the oil would cause a mess / problem. I opted to wt some paper towel and clean up what I could of dirt, cobwebs, dust, grease with particulate in it.

Would anyone know if emptying a can of brakekleen on the hub and bearings would be safe -- as long as I regreased everything?


Once it was all back together, still on the stand -- I decided to start the MC. It started up fine, and shifting into 1st had no initial problems. After running for 30 seconds at higher rpms (2-3K) -- I heard a strange noise. Nothing grinding, but just a strange very faint thudding/clunking. Very, very faint.

Hard to tell what it sounded like with my head so close to the exhaust.

Maybe this is all in my head -- and it's just making the noise with the rear in the air - no surface contact, but I was concerned. I shifted through the rest of the gears without issue. The sound stayed consistent. Once I get the front steering bearings replaced I'll have a better idea of the riding sound. Not what's just in my head.

But if anyone can think of what the noise is, I'd love to hear thoughts on it.

 

you might be hearing backlash in all the gears, try holding the back brake on slightly, just a little drag, to take the backlash out of it and see if the noise goes away

 

Too much fibre in your diet? Lol

 

I'm curious as to why you felt the need to run a different oil in the rear end. The factory book clearly specifies SAE80, GL-4; and says that 80/90 Hypoid gear oil is fine too.

I don't know if anyone will "have proof" that running the wrong gear oil might damage something, because I doubt that many folks are doing that.

I would start by using the recommended oil in the final drive.

In answer to your other questions/comments: those brake shoes look fine; they appear to be replacements. You can "flush" as much as you want with BrakeKleen, but keep in mind that there is no way to effectively remove the rear wheel bearings to re-lube them without destroying them.

 

My reason is anecdotal at best. I'd read others used it. With the potential age of the old stuff, I figured anything newer is better. While I think I put GP-4 in the original post -- I did check to ensure it was GL-4 rated, for what it's worth.

Once the bike comes down, I'll test ride it and check the temperature. I'll likely switch to 80-90 once this bottle is out (another change remaining).

I mostly left things as they were. There may be some very fine dust particles on the splines on the rear, after I wiped the housing down but I left it as is - as the BrakeKleen would have degreased the bearings. I just took a towel to wiping what I could. Already looked 3-5x better.

 

Aside from what I wiped off -- what would be recommended to grease the splines / final drive spline receiver with? Would waterproof grease work fine to rub all around in there // on top of the old stuff, or is a wipe down and regrease in order?

 

Used wheel bearing grease on mine, no harm getting it back to clean.. a bit o' gasoline on a tooth brush and a rag should do it.

 

Yamaha calls for a molybdenum disulphide grease for those splines. It's an extreme pressure grease. Regular bearing grease is designed to flow a bit and won't stay on the spline faces.

 

I found the Yamalube variety of it.

http://www.amazon.com/Yamalube-Molybden ... B005XA2EQK

Can I expect that this is whats already packed into the rear? That is to say -- mixing whats in there shouldn't be a problem with packing the new stuff in, correct?