Author Topic: Clutch Not Holding Under WOT: RECTIFIED  (Read 5449 times)

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High On Octane

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on: August 18, 2013, 04:17:30 pm
The Blackhawk is running great!  I'm pretty sure the last problem I had was due to the loose wire on the coil ground.  But alas, another problem arises.  Friday and Saturday night I was out hot rodding around town, and while the bike ran like a beast I was having trouble getting the clutch to hook up under 3/4-Full throttle.  The bike was pulling so hard that the clutch would slip until almost 5000RPMs.  I know people have reported issues with this before, it sounds like these clutches are known for having weak basket springs.  When I had it all apart a couple months ago doing the alternator/rotor the clutch plates still had plenty of material left and I'm thinking that there still is life on them now.  I'm thinking my problem is from when the return oil pump got clogged and dumped all the crankcase oil into the primary.  I have a feeling that the friction modifiers in the engine oil has left a coating on the clutch plates.  Any recommendations on how to clean them up WITHOUT pulling the primary cover?   ???   I've had that damn thing off to many times and am in no mood to pull it again unless I have to.  Thanks.

Scottie
« Last Edit: June 18, 2014, 12:55:44 pm by High On Octane »
2001 Harley Davidson Road King


classicrider

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Reply #1 on: August 19, 2013, 04:48:47 am
Scottie,i remember years ago using water based degreaser (pretty cheap and came in 4 liter container) in the primary(yes you will have too break the seal on the primary but at least won't have to remove it),i just poured a good litre in there and went for a slow ride around the block working the clutch a few times then dumped that and then use ATF F ,that can actually be a little too grippy for smooth takeoffs,but at least it works.
colin
« Last Edit: August 19, 2013, 04:53:03 am by classicrider »


High On Octane

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Reply #2 on: August 20, 2013, 01:56:52 pm
Changed out the oil to Type F ATF.  It's slipping less and seems to fully engage sooner than it was but definitely still slipping some.  Hopefully after a few more miles it will settle in.

Scottie
2001 Harley Davidson Road King


Ice

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Reply #3 on: August 21, 2013, 03:38:04 am
 My spydy sense tells me friction modifiers are not the root cause of the slippage.

Just a hunch.
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High On Octane

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Reply #4 on: August 21, 2013, 03:47:37 am
Me too.  Shitty springs?  Are stiffer springs available?

I actually just took the Blackhawk to get a beer and it's weird.  I can tell the clutch is slipping but the bike is freaking screaming and even with the clutch slipping it feels like it's accelerating faster than before.  It's running AWESOME right now!  If I can get that clutch to hook up I could lay a nice 1/4 mile time down.  :D

Scottie
2001 Harley Davidson Road King


High On Octane

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Reply #5 on: August 21, 2013, 04:17:37 am
NEXT STOP, Old Chicago!  Clutch isn't slipping at all at less than 2/3 throttle, only when I'm in it to win it.

Scottie
2001 Harley Davidson Road King


High On Octane

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Reply #6 on: August 21, 2013, 02:54:49 pm
Okie Dokie.  The Blackhawk is my hot rod, and all though I smoked a chick in a new Mustang Friday night, I need to address this clutch issue.  The bike is clearly producing more power than this clutch was originally intended to handle.  Hitchcock's has SEVERAL options for improving the clutch.  I'd really like to upgrade to the belt drive setup, but my wife would cuts my balls off and feed them to me if I spend another $700 on my bike for a single part.    :P

I'm thinking of doing the Clutch Service Kit (Improved) - 7th listing from the top Part# 90222
And possibly the Pressure Plate Kit - 10th listing from the top part# 90043

http://www.hitchcocksmotorcycles.com/accessory-gearbox-clutch-primarydrive

Thoughts/Input?   ???

Scottie
2001 Harley Davidson Road King


D the D

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Reply #7 on: August 21, 2013, 03:05:07 pm
I wish they said who made the plates.  They list some that are EBC and Sureflex which guarantees the quality.
Check the warranty and recommendations for whatever you get 'cause EBC used to state that running ATF in the primary voided their warranty.
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High On Octane

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Reply #8 on: June 10, 2014, 03:19:06 am
Well, here I am again.  Brand new clutch plates and springs and the M-F'er is still slipping really bad.  It wasn't slipping at all when I first installed the new clutch, then I was inside the primary and refilled with Advance Auto Type F and it started slipping like a punk beeotch again and hasn't stopped.  It's even worse now, anything over 1/3 throttle and it breaks loose and revs up.  Just to prove a point to myself, I loosened the clutch cable while riding to where the lever didn't even work and it still broke loose.  If I bump/touch/hold the clutch lever at all it completely breaks loose immediately as soon as I put any tension on the cable.  Is something not right inside of the primary?  Did I install something wrong?  I'm at a total loss here and it's really pissing me the F off. 

ANY suggestions are better than none at all.  Please help me out.  :(

Scottie J
2001 Harley Davidson Road King


ace.cafe

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Reply #9 on: June 10, 2014, 04:04:51 am
You could try to scuff up the metal plates with very coarse emery paper
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High On Octane

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Reply #10 on: June 10, 2014, 12:13:06 pm
You could try to scuff up the metal plates with very coarse emery paper

I had actually thought of this and may do it, but the steel plates are brand new as well and appeared to have a nice texture to them.  But as I was laying bed last night I had a thought.  Like I mentioned, the very moment I put any tension on the clutch cable what-so-ever it revs up freely.  Is it possible that the clutch adjustment itself (the scissor mechanism adjustment on the basket) is already out of spec and holding the basket slightly open?  ???

Man, I really need to get a Newby......
2001 Harley Davidson Road King


High On Octane

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Reply #11 on: June 10, 2014, 01:16:48 pm
Well I adjusted the scissor and put a little more slack in it but it didn't help too much.  So I added some Lucas Stop Slip for automatic transmissions and it definitely helped.  I can at least get on it a little bit now without it revving freely.  I have a feeling I need to go back in there and disassemble the clutch, clean all the plates with brake cleaner and then sand the hell out of the steel plates with some emery cloth or 80 grit paper or something of the sorts.
2001 Harley Davidson Road King


Bullet Whisperer

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Reply #12 on: June 10, 2014, 01:40:14 pm
Scottie - do you have any excessive radial play between the clutch centre and the basket [like big end play] ? This could cause creep between the plain and the friction plates, due to the forward 'pull' exerted by the engine and induce slippage. Other than that, is there any end float at the clutch centre / mainshaft [should be none], or is the clutch operating mechanism 'bottomed out' somewhere when there is slack in the cable - I have no experience of the scissor clutch, but I am thinking along the lines of when a clutch operating arm can go hard against the inside of an outer gearbox cover and cause slip, even with slack in the cable?
 B.W.


High On Octane

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Reply #13 on: June 10, 2014, 01:58:24 pm
The clutch basket definitely has some play in it, but I'm sure that is the problem as it WAS working great before.

FWIW  This what the scissor assembly looks like.

« Last Edit: June 10, 2014, 02:01:57 pm by High On Octane »
2001 Harley Davidson Road King


gmmechanic

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Reply #14 on: June 13, 2014, 01:08:51 am
I had a similar issue with my old shovelhead years ago...what I found was the slots in the basket had become enlarged slightly and deformed , causing the plates to cock sideways ever so slight but just enough to prevent smooth sliding...of course I was hard on a bike back the ;D ;D...just s thought... 8)
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High On Octane

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Reply #15 on: June 14, 2014, 04:47:47 am
Upon riding to work this morning, it seems like the Lucas (oil, not "smoke"  ;) ) Transmission Stop Slip is helping out the slipping issue.  It still slips a bit when cold but gets better as it warms up, and has progressively gotten better overall since I put it in the primary.  I also figured out why I've been having such a bitch of a time getting the cable adjusted correctly.  It turns out that I made the cable free play too long and the lever adjuster is quite literally on it's last thread of adjustment.  So I put it where it felt good and wrapped some electrical tape around the the threads of the adjuster to hold the nut in place and I didn't have any issues riding home.  In fact the only time it slipped was at pretty much WOT, but if I roll back off for a moment I can feel it grab and if I ease back into it it doesn't usually slip.  In fact, it almost acts like a torque converter, but it slips just a bit too much.  Who knows, maybe in another 100 miles or so it will finally re-seat itself.

gm - The slots in the basket were in fact a little enlarged, but not too bad.  But I completely rebuilt the basket and replaced every part that is replaceable.

Scottie J
2001 Harley Davidson Road King


ace.cafe

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Reply #16 on: June 15, 2014, 11:50:48 pm
We have also tried B&M Trick Shift for better clutch holding.
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High On Octane

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Reply #17 on: June 18, 2014, 01:08:13 am
I don't know what the hell is going on but the clutch was working fine the last couple of rides and now today the SOB is slipping again.  What gives?!  I guess I'll just have to pull the basket apart and sand all of the surfaces with some 36 grit, hose with brake cleaner again and find some kind of additive that makes oil sticky.    Maybe switch to Trick Shift, but that shit is expensive.   :-\

Scottie J
2001 Harley Davidson Road King


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Reply #18 on: June 18, 2014, 01:17:45 am
I don't know what the hell is going on but the clutch was working fine the last couple of rides and now today the SOB is slipping again.  What gives?!  I guess I'll just have to pull the basket apart and sand all of the surfaces with some 36 grit, hose with brake cleaner again and find some kind of additive that makes oil sticky.    Maybe switch to Trick Shift, but that shit is expensive.   :-\

Scottie J

Might be time for a belt clutch ;)
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High On Octane

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Reply #19 on: June 18, 2014, 12:55:07 pm
Suck It Clutch Pack!!!     ;D

I can't have a slipping clutch that progressively gets worse every time I ride.  So last night before I went to bed I pulled the bike up on my front step and yanked the primary cover again.  Good news is, with the new rear set controls I don't have to remove anything extra to get the cover off because there is nothing in the way now.   ;)    Also discovered that when pulling the clutch pack apart that if I leave the center stud with the scissor adjuster on holding the 2 pressure plates together, they stay together making assembly and disassembly a lot faster and easier.  The friction plates didn't appear to be glazed so I just cleaned them up good.  The steel plates and pressure plate on the other hand?  Well, they got a real good work over.  I took a 50 grit 3" grinding disc attached to my drill to them.  At moderate speed and pressure, I quickly started going over all the contact surfaces of the steel plates.  I made 2 passes on each surface, and then went over the pressure plate as well.  Even with my oily latex gloves on I could feel my fingers grabbing roughly on the new surfaces.  I didn't use a lot of pressure when doing this because I wasn't actually trying to remove any metal, I was just trying to score the surface so that they would grab the friction plates when engaged. 





I also read on Hitchcocks clutch tech page that if the slots in the basket and/or the tabs on the friction plates have any burrs in them that it can cause the plates to not seat properly and to file them down.  The plates were fine but there were a few burrs in the basket so I took another grinding disc and folded it in half and used that to remove the bulk of the burrs and clean up the slots.  The results?  The first time I let the clutch out it started grabbing almost immediately with the lever about half way out and then engaged quite firmly.  I zig zagged thru the neighborhood and was ecstatic at how much faster the bike accelerates now.  I always thought that my bike was fast and I knew there was some slip before, but when I launched from the stoplight on the main drag before getting back home, I damn near red lined 3rd gear before I got to the next stoplight!    :o  It always sounded like a beast, but it is DEFINITELY accelerating much faster than it ever has before.  EVER.  Like mind boggling faster.  Now lets hope that it stays this way and doesn't start slipping again.  I have a feeling that it won't after what I did to it last night.  Also, Hitchcocks states on that tech page that the use of ANY type of ATF is the recommended fluid type.  So I filled it back up with the Castrol Import AFT which is a semi synthetic oil and what I seemed to have the best luck with before.


Scottie J
2001 Harley Davidson Road King


ace.cafe

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Reply #20 on: June 18, 2014, 02:35:43 pm
That's good!

We have used all kinds of ATF, and it has been good in Bullets'
When it still slipped, we had better results from Type F, and also Trick Shift. Just for the record, the Type F has higher levels of friction modifiers than GM type ATF. I know you had a problem with the Advanced Auto Type F, but I assure you that we have never had any problems with Type F, and it has solved some slipping for us. I think that what happened with your AA Type F was an anomaly. We have never seen that. I don't think you would see that happen again in your bike, either.
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High On Octane

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Reply #21 on: June 18, 2014, 02:50:21 pm
I think you're right Tom.  I clearly had some other underlying issue that was causing the slipping being that I tried several different types of fluid.  I know this much.  I'm pretty sure I just turned my scissor clutch into a race clutch.  It grabs harder than the dual friction centerforce clutch I had in my '75 firebird now.   ;D   I ripped on her pretty hard coming into work this morning and never even had the slightest sign of slipping, quite the opposite.  I actually stalled it once.   LOL   ;D

Scottie J
2001 Harley Davidson Road King


ace.cafe

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Reply #22 on: June 18, 2014, 02:59:54 pm
I think you're right Tom.  I clearly had some other underlying issue that was causing the slipping being that I tried several different types of fluid.  I know this much.  I'm pretty sure I just turned my scissor clutch into a race clutch.  It grabs harder than the dual friction centerforce clutch I had in my '75 firebird now.   ;D   I ripped on her pretty hard coming into work this morning and never even had the slightest sign of slipping, quite the opposite.  I actually stalled it once.   LOL   ;D

Scottie J

Eventually, that friction scoring on the steel plates will become less effective because it smoothes off the biting edges from wear.  We have seen that. You just have to pay attention to how it feels, and re-do it from time to time. I'd get some extra steel plates on hand.

Also, the fluid level should be such that the lower chain run should just partially dip into the fluid. This will fling it all around inside, but not create too much friction drag on the chain,  and that will help by reducing unwanted heat.
« Last Edit: June 18, 2014, 03:04:21 pm by ace.cafe »
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High On Octane

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Reply #23 on: June 21, 2014, 06:51:44 am
Once again it worked great for a couple of rides and started slipping again, but only on occasion.    Turns out the cable knuckle I made wasn't fitting the new clutch cable because the hole for the ferrel was too big.  So I put a small hose clamp around the ferrel on the knuckle to hold it in place and keep it from moving around.  I also picked up some Trick Shift and filled it with that.  Clutch is working perfect now, no slip, no drag and smooth shifts.   :D


Scottie J
2001 Harley Davidson Road King