HarleyTechTalk

Technical Forums => EVO 1340 => Topic started by: 1340evo on July 11, 2017, 01:46:26 AM

Title: Is the tapered 84-89 main shaft really that bad????...........
Post by: 1340evo on July 11, 2017, 01:46:26 AM
Is the 84-89 tapered shaft really that bad?... I know I have a chewed up one now but that's because the inner hub has split for some reason.. I'd guess overtightening of the nut, poor manufacture of the part (square corners in the keyway leading to cracking or poor material) or undertighterning of the nut... When I removed it, the nut came off quite easily.. But the hub was still stuck on the taper and I had to make a puller to pull it off...
So installed right with a quality part... is it worth the change?

I think the upgrade to the 90 splined shaft with a 90-93 clutch is a good idea, but people have forgotten a lot of what's involved (primaries, push rods etc)... and the bits are not that easy to find here in the UK... (I'd like to see the part before buying if poss)...
It would also be a lot cheaper to put back the taper set up?..

So, is it worth doing.. or stick with the taper and hope it lasts?...
Title: Re: Is the tapered 84-89 main shaft really that bad????...........
Post by: FSG on July 11, 2017, 02:38:30 AM
later hubs have a steel center, there's also a reinforcing ring to prevent the inner cracking at the keyway

so it depends on the $$$$ and time available

(http://www.vtwinmfg.com/WebPics/18/18-8240a.jpg)

http://www.vtwinmfg.com/webapp/wcs/stores/servlet/VTwinProd1_10101_10102_3297178_-1

(http://i.imgur.com/61edeFB.png)
Title: Re: Is the tapered 84-89 main shaft really that bad????...........
Post by: 1340evo on July 11, 2017, 04:38:58 AM
It's a steel one thats cracked on mine.. the ring is interesting though...

So.. is it stop with the taper option??  In theory like a morse taper on a drill bit, it should be capable of tranmitting many tones of drive without failing...?
Title: Re: Is the tapered 84-89 main shaft really that bad????...........
Post by: Burnout on July 11, 2017, 04:45:10 AM
It's not bad materials or a bad part, it is a POS design. There is no fixing it.

The reinforcement ring does not work. I have cracked hubs with the ring installed.
I have tried lapping the hub to the shaft and careful torquing of the retaining nut.
It always fails.

There is nothing wrong with the tapered shaft, it was used for years on the four speeds with little problem.
The problem with the four speed clutch was rotating mass and basket wobble.
The huge four speed hub did not flex and held a great grip on the taper.

The problem with the tapered shaft 5 speed clutch is the hub design and bearing used.
The rotating mass of the hub was reduced and a big bearing was used to support the basket.
They took so much mass out of the hub there was not enough strength for it to hold the taper.
Then they cut the keyway slot and introduced a stress riser and an easy place for it to crack.

Crack is what the engineers were smoking!

And whoever told you, you have to change primary covers is also smoking the same "Potty mouth".
If you change primary covers you also have to change starters and I'm sure the trans case too.
Title: Re: Is the tapered 84-89 main shaft really that bad????...........
Post by: 1340evo on July 11, 2017, 05:58:22 AM
Fair point.. and yes.. you do have fracture points in the key slot.. TBH it would probably work better without the key slot!...

so back to splines?.. 90 shaft, 90-93 clutch.... still looking :)
Title: Re: Is the tapered 84-89 main shaft really that bad????...........
Post by: Hillside Motorcycle on July 11, 2017, 06:01:46 AM
Quote from: Burnout on July 11, 2017, 04:45:10 AM
It's not bad materials or a bad part, it is a POS design. There is no fixing it.

The reinforcement ring does not work. I have cracked hubs with the ring installed.
I have tried lapping the hub to the shaft and careful torquing of the retaining nut.
It always fails.

There is nothing wrong with the tapered shaft, it was used for years on the four speeds with little problem.
The problem with the four speed clutch was rotating mass and basket wobble.
The huge four speed hub did not flex and held a great grip on the taper.

The problem with the tapered shaft 5 speed clutch is the hub design and bearing used.
The rotating mass of the hub was reduced and a big bearing was used to support the basket.
They took so much mass out of the hub there was not enough strength for it to hold the taper.
Then they cut the keyway slot and introduced a stress riser and an easy place for it to crack.

Crack is what the engineers were smoking!

And whoever told you, you have to change primary covers is also smoking the same "Potty mouth".
If you change primary covers you also have to change starters and I'm sure the trans case too.

Spot on!!
Title: Re: Is the tapered 84-89 main shaft really that bad????...........
Post by: prodrag1320 on July 11, 2017, 11:14:54 AM
Quote from: 1340evo on July 11, 2017, 04:38:58 AM
It's a steel one thats cracked on mine.. the ring is interesting though...

So.. is it stop with the taper option??  In theory like a morse taper on a drill bit, it should be capable of tranmitting many tones of drive without failing...?


we still have a lot of these rings in stock if anyone wants one,they wont repair a already cracked hub,and are only a band aid for the hub not cracking in the first place.better off going to the later splined stuff
Title: Re: Is the tapered 84-89 main shaft really that bad????...........
Post by: tomfiii on July 11, 2017, 11:27:49 AM
They are ok if the ring has been placed ,which HD did on the -A or -B ,also the clutch hub replacement with the steel center is great.
Title: Re: Is the tapered 84-89 main shaft really that bad????...........
Post by: 1340evo on July 11, 2017, 12:12:06 PM
ok.. just had a wobble when primarys were mentioned.. back to plan A...

so will this clutch do

[url=http://www.1990-Harley-Davidson-FLHS-Electra-Glide-Clutch-Basket-w-Primary-Gear-Chain

cheers
Title: Re: Is the tapered 84-89 main shaft really that bad????...........
Post by: Mark222 on July 11, 2017, 12:21:14 PM
Looks correct, now just need splined shaft to fit,

Mark
Title: Re: Is the tapered 84-89 main shaft really that bad????...........
Post by: 1340evo on July 11, 2017, 01:34:49 PM
Mmmm $350 by the time its here?.. bit expensive... shaft another $200 plus?....

will keep a look out this side

Actuasly, part of our company is in NJ... wonder how much to ship there... will ask ;)

thanks for all your help guy's... limited knowadge this side...
Title: Re: Is the tapered 84-89 main shaft really that bad????...........
Post by: Burnout on July 11, 2017, 04:50:33 PM
For $200 you can get a complete take out gear set off Ebay Up to 05? will fit.

Title: Re: Is the tapered 84-89 main shaft really that bad????...........
Post by: 1340evo on July 11, 2017, 11:41:15 PM
Maybe.. but it delivery and tax that kills it here.. .You pay 20% on the bit AND shipping costs.. plus a UK delivery cost of around £8

so $200 and $50 to ship ends up being at least $310 delivered....  :emsad:
Title: Re: Is the tapered 84-89 main shaft really that bad????...........
Post by: Rugby_fxdwg on July 12, 2017, 04:58:35 PM
Dumb question is how do you know you've got an issue before you take it apart? Is it an issue shifting our pouring out? Don't mean to hijack the thread but would like to know how ya found the issue...
Title: Re: Is the tapered 84-89 main shaft really that bad????...........
Post by: 1340evo on July 13, 2017, 01:11:58 AM
you probably only know when you get vibration (nut lose or drum puhed back due to split) or you lose drive.. I was actually checking the stator to see if it had come lose... and it all went south from there ....
Title: Re: Is the tapered 84-89 main shaft really that bad????...........
Post by: Rugby_fxdwg on July 13, 2017, 02:40:30 PM
Sorry that really sucks... I'm hopeful ya get her back on the road soon with out a lot of $$$$
Title: Re: Is the tapered 84-89 main shaft really that bad????...........
Post by: 1340evo on July 14, 2017, 11:11:16 AM
ok.. thanks.. all bits ordered and the bike pulled in bits ready for when they get here... output shaft spacer is still to be okked at as people say a 89 one isnt too good.. dont know why.. maybe they crack?... may be worth replacing with a better one if anyone has the info... cheers.