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Bad noises from my Tranny
Posted: Sun Jun 09, 2013 11:40 pm
by DonW
Hello All, Just reassembled my R100GS. Put in the new rebuilt tranny with all new bearings, and the "long" 5th gear from Ted Porter.
The transmission turned smoothly and shifted through all gears before installation. It shifts perfectly and runs smoothing through all 5 gears on my initial test drive (about 5 miles, including freeway). When I put it up on the center stand and spin the wheel by hand (clutch held in) and go through the gears it is smooth and quiet.
BUT--- I put the bike securely on the centerstand with the rear wheel off the ground, started the engine, and ran through the gears in my garage. HOLY CRAP! It sounded like the tranny was filled with gravel. The rattling got progressively louder going from 1st to 5th. 5th gear sounding like there was a machine gun firing inside the tranny box. Took it out for another brief ride- smooth and quiet.
So, I'm hoping it is the loose gears banging against each other with each engine pulse. With no load, there is "slop" in the gear train-we're all familiar with the rattling transmissions on these old airheads.
I hope.. I hope... anyone else have ideas?
Thanks,
Don
Re: Bad noises from my Tranny
Posted: Mon Jun 10, 2013 12:02 am
by richard t
contact Ted porter if he sold you the tranny, he'll tell you what you need to check
Re: Bad noises from my Tranny
Posted: Mon Jun 10, 2013 12:13 am
by robert
.......So, I'm hoping it is the loose gears banging against each other with each engine pulse. With no load, there is "slop" in the gear train-we're all familiar with the rattling transmissions on these old airheads......
You have answewed your own question.
Re: Bad noises from my Tranny
Posted: Mon Jun 10, 2013 1:06 am
by DonW
richard t wrote:contact Ted porter if he sold you the tranny, he'll tell you what you need to check
I just bought the special 5th gear from Ted. I rebuilt the tranny myself.
D
Re: Bad noises from my Tranny
Posted: Mon Jun 10, 2013 5:05 am
by Ken in Oklahoma
I'm inclined to think vibrating or gears shaking against each other might be the cause as well. Although one would think that in at least one of the 5 gears selected when on the stand would have quieted the noise.
You might drain the oil in your transmission and look at the magnet on the drain plug. Particles would say "problem" whereas no particles would be inconclusive. If the gear oil looks good I see no problem putting it back in.
You know, I don't think I've ever put my bikes on the center stand and run through the gears. I wonder if this is much of a test for anything.
Does the noise show up only when in gear on the stand, or will it also happen in neutral on the stand? (With engine running of course)
Have you had the chance to evaluate warm gear oil vs cold gear oil? For a clattering gear I would expect that to make a difference.
As you can tell, I'm throwing some "stuff" on the wall, mostly to inspire the thought process. The fact is that I've never been inside an airhead transmission (though I have one that needs fixing, though it's a broken cluster gear which makes it suitable for parts--at best.)
You always keep us posted on your "adventures". Thanks for that.
Ken
Re: Bad noises from my Tranny
Posted: Mon Jun 10, 2013 7:13 am
by LeeGP
A friend of mine had the same issue with his oilhead gs. As I recall, after a lot of worry, he found out that it was perfectly normal for the bike to exhibit the tranny noise when run in gear on the centerstand. Can't remember the reason(s). That bike has over 100,000 on it now with no transmission issues.
Re: Bad noises from my Tranny
Posted: Mon Jun 10, 2013 12:18 pm
by DonW
Ken in Oklahoma wrote:I'm inclined to think vibrating or gears shaking against each other might be the cause as well. Although one would think that in at least one of the 5 gears selected when on the stand would have quieted the noise.
No noise in 1st, increasing noise the higher the gear
You might drain the oil in your transmission and look at the magnet on the drain plug. Particles would say "problem" whereas no particles would be inconclusive.
Gonna do that! If the gear oil looks good I see no problem putting it back in.
You know, I don't think I've ever put my bikes on the center stand and run through the gears. I wonder if this is much of a test for anything.
Please! Everyone do this TODAY and let me know what sounds appear... 
Does the noise show up only when in gear on the stand, or will it also happen in neutral on the stand?
No noise in Neutral (With engine running of course)
Have you had the chance to evaluate warm gear oil vs cold gear oil? For a clattering gear I would expect that to make a difference.
Same noise both ways, did have a chance before/after test ride
As you can tell, I'm throwing some "stuff" on the wall, mostly to inspire the thought process. The fact is that I've never been inside an airhead transmission (though I have one that needs fixing, though it's a broken cluster gear which makes it suitable for parts--at best.)
You always keep us posted on your "adventures". Thanks for that.
Thanks Ken! I believe in sharing your defeats as well as triumphs- we all get to learn from each other
Ken
Thanks, Don
Re: Bad noises from my Tranny
Posted: Mon Jun 10, 2013 12:57 pm
by Jeff in W.C.
DonW wrote:I believe in sharing your defeats as well as triumphs- we all get to learn from each other
Thanks, Don
I was very tempted to go after that barn find GS, after hearing what you've gone through, I'm glad I didn't. It would have been beyond my available cash and time. I've learned a lot from that.
Anyway, it's always good to hear from you. One of these days, I will be able to get back on the bike, but issues on the home front keep me off it these days.
Re: Bad noises from my Tranny
Posted: Mon Jun 10, 2013 1:07 pm
by Deleted User 287
Jeff in W.C. wrote:One of these days, I will be able to get back on the bike, but issues on the home front keep me off it these days.
You are making the right decision. DAMHIK
Re: Bad noises from my Tranny
Posted: Tue Jun 11, 2013 1:46 am
by Duane Ausherman
I am not there to hear it rattle, but.............
With the bike on the center stand there is little drag and at idle it is normal to make some noise. I suspect that you didn't test anything at all.
Rev it up and I predict that most/all of the noise will go away if the transmission is without problems. I am not there to hear it though.