Rear Gear Noise

[mkunert]

Is some rear gear noise normal? I just bought a 2001 with 800 miles on it last year. I don't remember hearing any noise from the rear gear on my Magna, but I sold that 20 years ago. I also just had some Metzlers put on, and it seems I can hear it more (no, it's not tire noise, I checked on the center stand). I've always thought differentials should be silent if they're set up correctly.

 

[Calimus]

Might be time to change the gear oil back there.

I think a lot of bikes come with thin break-in oil in the rear diff's. Might be time to change to something thicker or for whatever reason, you might be a bit low. Try checking the level or just changing it out to the proper weight and see if that helps.

 

[firefly]

Is some rear gear noise normal? I just bought a 2001 with 800 miles on it last year. I don't remember hearing any noise from the rear gear on my Magna, but I sold that 20 years ago. I also just had some Metzlers put on, and it seems I can hear it more (no, it's not tire noise, I checked on the center stand). I've always thought differentials should be silent if they're set up correctly.

Yes Metzlers do make some noise, I also 2nd the diff oil changing. I added some duralube to the diff oil and it made it much smoother to.
Do not add any additive to the motor oil or else your clutch will slip.
also make sure the axle nut is not too tight it is not chain drive and the manual has it 110 ft but 55 ft is all that is needed.
take the bike for a spin then touch the diff , if hot then the axle nut is too tight.
I hope that helps
________
marijuana sativa

 

[mkunert]

Thanks. I take it by the responses that I should not be hearing noise from the diff.

Just recently change the gear oil because of the noise. Correct weight and level. I'll try the axle nut. Maybe they over-torqued it when they put on the tire. Thanks much for the advice.

 

[one2dmax]

We have found a few diff's that had the large nut on the pinion loose. You might want to check yours while you are looking things over. If it is loose just zap it a bit with a good impact gun.


Sean

 

[Lew L]

Say what lube do you guys suggest other than Yamaha's brand of 80/90 shaft drive gear lube????????
I found a small amount of "mush" on the magnet and the oil was surprisingly dark compared to the new oil.

Lew

 

[mikemax04]

Like Sean said, it could be the pinion nut. Also could be that water got in there somehow and did a number on the bearings. Did you take a screwdriver to your ear and probe from where exactly the noise is coming from? Can you describe the sound you're hearing? Makes me wonder why only 800 miles on a 2001 bike. No differential runs completely silent, but it shouldn't make a racket either. Why do you suppose the Harley guys run loud mufflers? That's right, to drown out all the other terrible noises their bikes make. (humor maybe) Keep us posted on what you find.

 

[mkunert]

Lew- I found the same mush on mine. Just a little bit of metal filings which, the manual says, is normal. I use the Valvoline 80-90 oil, which is sufficient. I would have used the synthetic Valvoline 80-90, but I still have a couple of bottles of the normal stuff left from another project.

I went back and topped off the diff. I had only filled it to the bottom of the fill hole. The manual says to fill it to the top of the bottom lip of the hole. That made all the difference in the world. Completely silent now.

Some guy bought my bike new in 2001 when he found out he had terminal cancer. Drove it 800 miles and then died. His wife stuck it in a barn for 4.5 years. I picked it up, and it needed a bit of work. I replaced all the fluids, and tuned the carbs. Took a long time to clean the surface rust off of it, but now it looks and runs great.

 

[mikemax04]

Glad you found the problem and an easy fix at that. Since you already changed the oil in the pumpkin, it made us believe that was the last thing it needed.......more fluid. Most rear ends are setup to fill 'till it runs out the fill hole. Great find on the bike and probably picked it up for a little more than a song.

 

[mkunert]

It really only brought up the level 1/2" at most, but that was the difference. I never would have thought.

Yeah, did get a pretty good deal on it.