2003 RT final drive question

[Indy Bill]

On my last outing I started hearing increased noise from the rear end when leaned to one side or the other, loudest around 60-70mph. I had heard this once before around 28K and thought it was just the Metzler 880 cupping. The dealer found that the rear wheel seal was leaking at the same time they replaced the rear tire so I figured all this time that the Metzler was just cupping. It doesn't feel like the rear drive was overheating, but with all the talk about rear end failures lately I am concerned. Had a second this evening so I took the bags off, grabbed the rear wheel (at 8 and 2 o'clock referenced by laying by the left side) and tried to move it side to side to see how much (if any) play there was. Dang if I don't hear a slight clunk. I performed the same test on the Wife's RT (same year, but has 6K on it verses the 35K mine does) and there is no clunk performing the same test. Your

thoughts?

 

I haven't changed the oil yet to see if there are any foreign bits in it......which brings the next question. The book says 90W. All I have found around here is 85-145W. Yes, what I have found locally is Hypoid gear API GL5 rated. Is the 85-145W an acceptable substitute?

 

TIA

[T__]

On my last outing I started hearing increased noise from the rear end when leaned to one side or the other, loudest around 60-70mph. I had heard this once before around 28K and thought it was just the Metzler 880 cupping. The dealer found that the rear wheel seal was leaking at the same time they replaced the rear tire so I figured all this time that the Metzler was just cupping. It doesn't feel like the rear drive was overheating, but with all the talk about rear end failures lately I am concerned. Had a second this evening so I took the bags off, grabbed the rear wheel (at 8 and 2 o'clock referenced by laying by the left side) and tried to move it side to side to see how much (if any) play there was. Dang if I don't hear a slight clunk. I performed the same test on the Wife's RT (same year, but has 6K on it verses the 35K mine does) and there is no clunk performing the same test. Your

thoughts?

 

I haven't changed the oil yet to see if there are any foreign bits in it......which brings the next question. The book says 90W. All I have found around here is 85-145W. Yes, what I have found locally is Hypoid gear API GL5 rated. Is the 85-145W an acceptable substitute?

 

TIA

 

TIA, your noise sure has all the ear marks of a feathering tire.. That’s not saying that your clunk is a good sign but the noise as you explained it sure sounds like tire feathering..

 

See if it makes the same leaned over noise with the clutch pulled in & the bike coasting while leaned over.. If the noise is worse on a cold tire then it sure points to tire feathering or cupping..

 

On that gear oil question? You should have no problem finding 80W90 gear oil.. I seriously doubt that 85-140 will cause any harm but will not say it’s OK to use.. I tried running 85-140 in my GoldWing & while it worked good in warm weather it spit out the final drive vent when operated in sub freezing temps at very high speeds.. With the cold weather flowability numbers 80 vs 85 being about the same I have no idea why but I quit using it as it was oiling up my rear tire.

 

Twisty

[Indy Bill]

See if it makes the same leaned over noise with the clutch pulled in & the bike coasting while leaned over.. If the noise is worse on a cold tire then it sure points to tire feathering or cupping..

 

Noise is still there when clutch pulled in, coasting, and leaned over. It's not there when riding in a straight line. Don't seem to notice it when the tire is cold, only after I have been riding for a while.

[Indy Bill]

More information: I had privately asked someone who's R bike technical expertise I hold in high regard about this noise. The response I got was he thought this noise was the tire tread I was hearing and not the rear drive self destructing......as long as the oil didn't show nasty metal bits in it. The slight klunk could be that it is shimmed a little loose and no big deal. <crossing my fingers>

 

With respect to the oil portion, he felt that 80-90W should suffice. I am having difficulties finding plain old 90W hypoid around this area. I will be procuring some tonight and changing the rear drive fluid after a test ride to see if the noise is there when the rear drive and tire are "cold", or only when both are "hot".

 

Thinking REAL hard about replacing the "suspect" bearing with the new-and-improved one this coming winter.

 

As always, you mileage may vary, and usually does.

[Boffin]

My dealer stripped and replaced the bearing on my FD under warranty due to noise like this. When it didn't go away he did the same for the gearbox. Before I took it back with the same problem still there I fitted new tyres. No more noise

 

If the bearing ain't broke don't fix it.

 

Andy

[Indy Bill]

I took it out for a spin this evening. Noise is there from 60 - 65mph when leaned, warm or cold....so not tempurature dependent. Drained the fluid and no filings, chunks, or other debris. Looks like I got some tire noise and possibly the FD isn't shimmed just exactly so. I feel somewhat better.