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Discussion Starter · #1 · (Edited)
I’m putting a 98" 37G build together. I've got the cams installed and the inner gear lash is 0, no binding, cams turn smooth as can be. With outer gears installed I’m getting .001, .0015, .00125, and .001. Am I good to go?

I see where Woods says .001" max and the S&S kit doesn't even mention gear lash.

Thanks,
Rick
 

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Gear lash

I would go with Bobby Woods' recomendation. We use his perameters and they come out very quiet. I have heard a job done by someone else that was very noisy who didn't follow Woods' instructions. We get the gears from Woods or Zippers. Good luck, Friday
PS very important that you have the gears clean enough to eat off of when doing your check.
 

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My readings on my gear lash, (37G's), were almost identical to yours. The slight variation, (.00025), represents 2 and one half tenths of one thousandth!! That could very well be your "tangent error", (your ability to hit the very tangent of the indicator plunger in the exact same spot as where you read .001 on the indicator).

If you truly have a reading of .00125, (like I did, don't worry about it). The set-up is near perfect. Mine doesn't make a sound. It doesn't get any better than that. Once the engine comes up to op temp, your lash is gone due to thermal expansion. You've done extremely well if you achieved the lash numbers that you state...

Like Friday1 said, cleanliness is ultimately essential. Use plenty of break-in lube on the gears before you button it up. Initial mating occurs when you fire the motor after installation and the gear pattern/lash develops when the gears mate/pattern. This will ultimately be the determination of how the gears will sound. Establishing the .001 gives the gears the clearance they need in order to break-in properly.

Like I said, mine don't make a sound, other than the expected whirring noise that replaces the chain driven noise you were used to.

MHO, DLR
 

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I'm going to be doing a 98" upgrade real soon and installing the gear drive 37's as well. Is there a specific type of break-in lube, or is it a generic item I can put up from any local automotive parts store ? Thanks
 

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I am using STP oil treatment as an assembly lube. It was recommended to me buy a guy who does lots of motor rebuilds. Says it is all he has ever used. About a third of the price as assembly lube (not that that was a determining factor).
I'll be using the existing Mobil 1Vtwin oil in the crankcase for break in. I'll change it after 500 miles.
 

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Discussion Starter · #6 ·
DLRVelocity1 said:
My readings on my gear lash, (37G's), were almost identical to yours. The slight variation, (.00025), represents 2 and one half tenths of one thousandth!! That could very well be your "tangent error", (your ability to hit the very tangent of the indicator plunger in the exact same spot as where you read .001 on the indicator).

If you truly have a reading of .00125, (like I did, don't worry about it). The set-up is near perfect. Mine doesn't make a sound. It doesn't get any better than that. Once the engine comes up to op temp, your lash is gone due to thermal expansion. You've done extremely well if you achieved the lash numbers that you state...



Like I said, mine don't make a sound, other than the expected whirring noise that replaces the chain driven noise you were used to.

MHO, DLR
With all the talk about whine I'm probably being a little over cautious. When moving the gears back and forth I can hear a little bit of clicking. Not a big deal?

Rick
 

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You are very close on the spec up to a though and a half is fine. If you go to larger gear you may end up with a whine. The very few that i have had to fix where too tight, and where from customers that had done it them selves and did not check it. I think you will be fine . I would run that. As if you do go to a over size you may be at a spec that would be too tight
 

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Discussion Starter · #9 ·
HDWRENCH said:
You are very close on the spec up to a though and a half is fine. If you go to larger gear you may end up with a whine. The very few that i have had to fix where too tight, and where from customers that had done it them selves and did not check it. I think you will be fine . I would run that. As if you do go to a over size you may be at a spec that would be too tight
Thanks Steve,

I figured I was borderline. I guess it's not that big of a deal to swap later if it's a problem.

Rick
 

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Discussion Starter · #10 ·
pa-glazier said:
Clicking indicates a loose fit. Whining is form a snug fit. You should check it with a dial indicator. See attachment.
Thanks,

I already checked it. See the first post.

Rick
 

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pa-glazier said:
Clicking indicates a loose fit. Whining is form a snug fit. You should check it with a dial indicator. See attachment.
Where would I find such a set-up? What should I expect to spend?
 
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