HarleyTechTalk

Technical Forums => Twin Cam => Topic started by: Tacocaster on March 05, 2021, 05:35:42 AM

Title: Measured Crank & Pinion Runout Redeux
Post by: Tacocaster on March 05, 2021, 05:35:42 AM
Have any of you with Gear Drive Conversions gone back to re-measure the Crank & Pinion Runout after a generous period of miles?

For example, I know Hossamania has been running his gear drive for ~15 years with great success - wish him many thousands more miles, in fact!

I'm just curious if the runout has in fact changed from the original measured 0.003/4 at installation, or if you've noticed any increased gear noise or damage (taking into consideration the age + hearing loss factors, of course).
Title: Re: Measured Crank & Pinion Runout Redeux
Post by: Hossamania on March 05, 2021, 10:38:48 AM
I have not measured mine, it's always made some clacking noise, especially when the oil is hot, but no increase in pinion whine. No pinion whine once I changed out for an undersized pinion gear after a month. I have no plans to check runout, just going to run it till it blows. For some reason, I think this motor was a Tuesday build, because it has given me no trouble, and I have given it every reason to do so.
Mine is an '01, not sure I would go gears on '03 and later, just from what gets discussed here.
Title: Re: Measured Crank & Pinion Runout Redeux
Post by: Scotty on March 05, 2021, 10:41:54 AM
Only one a 2003 Dyna that after 130,000 kms had an accident and the cam cover was damaged.
Run-out was exactly the same and everything looked good and all that was needed was a new cam cover for the motor.
The rest of the bike is another long story about finding parts but eventually it got back on the road.
Title: Re: Measured Crank & Pinion Runout Redeux
Post by: Tacocaster on March 05, 2021, 11:44:51 AM
Thanks guys. That's really what I expected to hear and happy to hear it confirmed, for the most part.

If you're good at the get-go there's really nothing that should change, I wouldn't think if you're '06 or older at least.
Title: Re: Measured Crank & Pinion Runout Redeux
Post by: kd on March 05, 2021, 01:26:31 PM
One hard downshift could change that in a hurry. I would measure it if you are concerned
Title: Re: Measured Crank & Pinion Runout Redeux
Post by: Tacocaster on March 05, 2021, 05:46:01 PM
That's good advice, KD.
Even with gear-driven cams, I suppose it makes sense to take a peek now and again to ensure the cam lobes are still good (not worn past the hardness) and measure runout while there.
Title: Re: Measured Crank & Pinion Runout Redeux
Post by: Scotty on March 05, 2021, 05:51:40 PM
Quote from: kd on March 05, 2021, 01:26:31 PM
One hard downshift could change that in a hurry. I would measure it if you are concerned

One hard downshift that moves the crank means you are likely to hear the cam gears whine like crazy or break so no need to measure  :hyst:
Title: Re: Measured Crank & Pinion Runout Redeux
Post by: Tacocaster on March 06, 2021, 05:42:39 AM
Yup, on a big change, fershur! You WILL be notified n' mortified!

Small change might just raise the noise level (at best) to tease you. Best to shut-down the jukebox and turn-up the right-ear hearing aid occasionally.
Title: Re: Measured Crank & Pinion Runout Redeux
Post by: Hossamania on March 06, 2021, 06:54:21 AM
If the bike has been ridden hard before the gear change, and the wheels haven't shifted, can the same be expected after installing gear drives? Do gear drives change the likelihood of runout increasing, or is it the same either way?
Title: Re: Measured Crank & Pinion Runout Redeux
Post by: Tacocaster on March 06, 2021, 07:32:01 AM
Quote from: Hossamania on March 06, 2021, 06:54:21 AM
If the bike has been ridden hard before the gear change, and the wheels haven't shifted, can the same be expected after installing gear drives? Do gear drives change the likelihood of runout increasing, or is it the same either way?

Now that's the question I SHOULD have asked at the first!
Title: Re: Measured Crank & Pinion Runout Redeux
Post by: kd on March 06, 2021, 07:57:46 AM
I doubt the gear drive mechanism could provide enough rĂ©sistance to stabilize a crank that wanted to scissor.  As Scotty said, with gears, you should be able to sense a change in the harmonics / sound in the gear case if it does slip.  That would be providing the change was significant and happened all at once.  I fear that it would be easy to get used to the change if it was over a longer period of time.  It may be thought of as normal as the engine loosened up with normal wear over time. 
Title: Re: Measured Crank & Pinion Runout Redeux
Post by: Hossamania on March 06, 2021, 01:59:38 PM
My question is, if an '03 up motor has 20,000 hard miles, hard downshifts, etc., and it is still in spec on runout, will gear drives increase the chance of runout becoming an issue more than if the tensioners were kept?
Title: Re: Measured Crank & Pinion Runout Redeux
Post by: Scotty on March 06, 2021, 02:34:00 PM
Quote from: Hossamania on March 06, 2021, 01:59:38 PM
My question is, if an '03 up motor has 20,000 hard miles, hard downshifts, etc., and it is still in spec on runout, will gear drives increase the chance of runout becoming an issue more than if the tensioners were kept?

No not at all they have very little pressure on the crankshaft as the camplate supports both the cams and the crank.
Title: Re: Measured Crank & Pinion Runout Redeux
Post by: Hossamania on March 06, 2021, 08:19:30 PM
I figured as much, didn't really see how there would be a difference.
Title: Re: Measured Crank & Pinion Runout Redeux
Post by: Hillside Motorcycle on March 08, 2021, 04:00:24 AM
Won't hurt to check it if concerned.
IF the crank slips enough, it'll break teeth and that could be a mess.
Title: Re: Measured Crank & Pinion Runout Redeux
Post by: Adam76 on March 10, 2021, 01:33:35 AM
Quote from: Hossamania on March 05, 2021, 10:38:48 AM
I have not measured mine, it's always made some clacking noise, especially when the oil is hot, but no increase in pinion whine. No pinion whine once I changed out for an undersized pinion gear after a month. I have no plans to check runout, just going to run it till it blows. For some reason, I think this motor was a Tuesday build, because it has given me no trouble, and I have given it every reason to do so.
Mine is an '01, not sure I would go gears on '03 and later, just from what gets discussed here.

That's good to hear Hoss, I'm planning on gears as soon as I can measure my pinion shaft runout (waiting on a magnetic base for my dial guage).

One question, how did you determine that you needed a different size gear one month after set up?  Did the gear whine suddenly get worse? 
Title: Re: Measured Crank & Pinion Runout Redeux
Post by: Armin on March 10, 2021, 01:56:36 AM
Look here:
https://www.sscycle.com/tech-info/instruction-sheets/-in-category/categories/instruction-sheets/valve-train-components

and download the instruction for early gear drive cams, everything is in there.

Armin.
Title: Re: Measured Crank & Pinion Runout Redeux
Post by: Hossamania on March 10, 2021, 05:21:35 AM
Quote from: Adam76 on March 10, 2021, 01:33:35 AM
Quote from: Hossamania on March 05, 2021, 10:38:48 AM
I have not measured mine, it's always made some clacking noise, especially when the oil is hot, but no increase in pinion whine. No pinion whine once I changed out for an undersized pinion gear after a month. I have no plans to check runout, just going to run it till it blows. For some reason, I think this motor was a Tuesday build, because it has given me no trouble, and I have given it every reason to do so.
Mine is an '01, not sure I would go gears on '03 and later, just from what gets discussed here.

That's good to hear Hoss, I'm planning on gears as soon as I can measure my pinion shaft runout (waiting on a magnetic base for my dial guage).

One question, how did you determine that you needed a different size gear one month after set up?  Did the gear whine suddenly get worse?

No, it pretty much whined from day one. I just put up with it thinking it wasn't that bad, plus those gears aren't cheap, but I am! Once changed, it was night and day difference, nice and quiet.
Title: Re: Measured Crank & Pinion Runout Redeux
Post by: Adam76 on March 10, 2021, 05:39:47 AM
Quote from: Hossamania on March 10, 2021, 05:21:35 AM
Quote from: Adam76 on March 10, 2021, 01:33:35 AM
Quote from: Hossamania on March 05, 2021, 10:38:48 AM
I have not measured mine, it's always made some clacking noise, especially when the oil is hot, but no increase in pinion whine. No pinion whine once I changed out for an undersized pinion gear after a month. I have no plans to check runout, just going to run it till it blows. For some reason, I think this motor was a Tuesday build, because it has given me no trouble, and I have given it every reason to do so.
Mine is an '01, not sure I would go gears on '03 and later, just from what gets discussed here.

That's good to hear Hoss, I'm planning on gears as soon as I can measure my pinion shaft runout (waiting on a magnetic base for my dial guage).

One question, how did you determine that you needed a different size gear one month after set up?  Did the gear whine suddenly get worse?

No, it pretty much whined from day one. I just put up with it thinking it wasn't that bad, plus those gears aren't cheap, but I am! Once changed, it was night and day difference, nice and quiet.

👍