Author Topic: Driveline lash  (Read 4355 times)

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Offline RoadKillHeaven

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Re: Driveline lash
« Reply #50 on: September 26, 2017, 09:07:03 pm »
The main reason automakers focus on perfecting slushbox transmissions is to satiate customers-who-have-nothing-better-to-do-but-bitch-and-moan about "perceived" driveline slop in a manual gearbox.
I guess I'll become one of those nagging old-farts one day...Untill then I enjoy my genuine "driveline slop"

Offline gpd323

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Re: Driveline lash
« Reply #51 on: September 27, 2017, 09:42:07 pm »
Steve's recommendation to tighten the throttle cable and bunch and then a barrel roll is spot on. I would say 90% of my DL lash/slop complaint is now outa here.

I currently have the EVO flash with a tweak. I won't say anything more because this is Steve's project.  :great:
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Offline Jerdurr

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Re: Driveline lash
« Reply #52 on: September 28, 2017, 01:46:00 pm »
Steve's recommendation to tighten the throttle cable and bunch and then a barrel roll is spot on. I would say 90% of my DL lash/slop complaint is now outa here.

I currently have the EVO flash with a tweak. I won't say anything more because this is Steve's project.  :great:
Pardon my ignorance, but I've been following this thread and trying to understand what the procedure is to remove the DL lash; all you need to do is tighten the throttle all the way...and that's it?
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Offline Deepsea

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Re: Driveline lash
« Reply #53 on: September 28, 2017, 07:09:36 pm »
Yes and no. The actual driveline lash is purely a mechanical function of how the gears fit together. However, the perceived feel of this lash can be minimized by adjusting the throttle cables as outlined by Steve. You're not changing the actual gear lash but you are taking the slop/error out of the TPS (throttle position sensor). It can make a significant difference, give it a try.
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Offline kawajohnny

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Re: Driveline lash
« Reply #54 on: March 18, 2018, 10:26:33 pm »
I know this topic has not been addressed here for several months but I may have a useful contribution to the issue of driveline lash. I have fairly aged Connie 14 with 123K on it (all mine). During a trip a couple of years back, literally between gas stops, I suddenly picked up a ton of driveline lash. This was at about 75K on the bike. Having been a bike shop tech/service manager for many years in the 1970s to 1990s timeframe I encountered the same problem on several shafties, primarily Yamaha. in EVERY case where backlash was a sudden onset issue, it was the spring on the driveline cam. In those cases, the cam spring had broken (other gradual-onset cases were CV/universal joint and extremely worn/improperly shimmed middle gearbox bevel gears).

Immediately after the above ride, I popped the drive shaft cover to take a peek at the joints...no apparent damage, slop or tell-tale debris inside. So, feeling I knew what the problem was (the spring behind the middle gearbox on the Connie) I continued to ride and learned, with a combination of re-learned clutch throttle technique, to ride without the backlash being a nuisance (other than me constantly being aware of it!). During this winter I finally broke down and pulled the middle gear box. Sure enough, the spring was broken. I found one online (check eBay!) for about $15 and a few bucks more for stuff like gasket, oil, downloaded service manual. I actually bought the spring before actually taking things apart...it was a cheap risk. Spent an evening and a morning replacing it (not difficult...just zero-rush time-consuming sitting on the floor working on it [a roll-around seat would have been welcomed!]..and a plentiful "refreshment" supply). Took the bugger out for a ride and, voila!, the lash was new-bike gone. Was a great time-with-a-buddy project.

This may not be the situation in every case but the above was the issue and solution for me for me.


Offline Steve in Sunny Fla

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Re: Driveline lash
« Reply #55 on: March 18, 2018, 10:49:12 pm »
I know this topic has not been addressed here for several months but I may have a useful contribution to the issue of driveline lash. I have fairly aged Connie 14 with 123K on it (all mine). During a trip a couple of years back, literally between gas stops, I suddenly picked up a ton of driveline lash. This was at about 75K on the bike. Having been a bike shop tech/service manager for many years in the 1970s to 1990s timeframe I encountered the same problem on several shafties, primarily Yamaha. in EVERY case where backlash was a sudden onset issue, it was the spring on the driveline cam. In those cases, the cam spring had broken (other gradual-onset cases were CV/universal joint and extremely worn/improperly shimmed middle gearbox bevel gears).

Immediately after the above ride, I popped the drive shaft cover to take a peek at the joints...no apparent damage, slop or tell-tale debris inside. So, feeling I knew what the problem was (the spring behind the middle gearbox on the Connie) I continued to ride and learned, with a combination of re-learned clutch throttle technique, to ride without the backlash being a nuisance (other than me constantly being aware of it!). During this winter I finally broke down and pulled the middle gear box. Sure enough, the spring was broken. I found one online (check eBay!) for about $15 and a few bucks more for stuff like gasket, oil, downloaded service manual. I actually bought the spring before actually taking things apart...it was a cheap risk. Spent an evening and a morning replacing it (not difficult...just zero-rush time-consuming sitting on the floor working on it [a roll-around seat would have been welcomed!]..and a plentiful "refreshment" supply). Took the bugger out for a ride and, voila!, the lash was new-bike gone. Was a great time-with-a-buddy project.

This may not be the situation in every case but the above was the issue and solution for me for me.

  you're talking about the big spring that loads the cam in the bevel drive, correct?  Steve
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