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Author Topic: CB750 - Clutch lifter plate  (Read 3028 times)

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Offline Johnie

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CB750 - Clutch lifter plate
« on: January 27, 2008, 12:43:53 PM »
I am taking your advise and replacing the 4 clutch springs while the cover is off.  Heck, at $2.50 each why not.  Is it wise or even necessary to force some grease into the lifter plate bearing?  Thanks for your clutch expertise...
John
1969 CB750K0 - Candy Blue Green (current)
1970 CB750K0 - Candy Ruby Red
1970 CB750K1 - Candy Gold
1973 CB750K3 - Candy Bacchus Olive
1974 CB750K4 - Flake Sunrise Orange
2000 1500 SE Wing


Honda's owned in the past:
1965 65SS, 1969 CB350, 1971 CB350, 1972 CL175, 1972 CB350, 1974 CB450, 1975 CB360T, 1977 CB750K, 1980 CM400E, 1981 CM400C
Oshkosh, WI  USA

Offline 754

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Re: CB750 - Clutch lifter plate
« Reply #1 on: January 27, 2008, 12:53:55 PM »
I think it gets oil splash.. never had to change one..

make sure you do the 4 bolts a bit at a time, on and off..
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Online MRieck

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Re: CB750 - Clutch lifter plate
« Reply #2 on: January 27, 2008, 01:01:41 PM »
 It's easy to break that piece......be careful
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Offline Tower

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Re: CB750 - Clutch lifter plate
« Reply #3 on: January 27, 2008, 01:03:42 PM »
You can apply grease to the clutch lifter rod if disassembled from the cover, otherwise the oil splash is enough, as 754 mentions,  to keep the "throw-out" bearing running smoothly.
« Last Edit: January 27, 2008, 01:07:16 PM by Tower »

Offline Johnie

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Re: CB750 - Clutch lifter plate
« Reply #4 on: January 27, 2008, 01:04:13 PM »
Geez...you guys are scarin' me.  Are you using a torque setting for the 4 bolts or just nice and tight?
« Last Edit: January 27, 2008, 01:06:50 PM by Johnie »
John
1969 CB750K0 - Candy Blue Green (current)
1970 CB750K0 - Candy Ruby Red
1970 CB750K1 - Candy Gold
1973 CB750K3 - Candy Bacchus Olive
1974 CB750K4 - Flake Sunrise Orange
2000 1500 SE Wing


Honda's owned in the past:
1965 65SS, 1969 CB350, 1971 CB350, 1972 CL175, 1972 CB350, 1974 CB450, 1975 CB360T, 1977 CB750K, 1980 CM400E, 1981 CM400C
Oshkosh, WI  USA

Offline andy750

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Re: CB750 - Clutch lifter plate
« Reply #5 on: January 27, 2008, 01:15:18 PM »
I think we have all broken that lifter plate at some point...I know I have....tighten each bolt in turn and evenly until they are all tight - check the shop manual for torque value. It can be done just have to be careful.

cheers
 Andy
Current bikes
1. CB750K4: Long distance bike, 17 countries and counting...2001 - Trans-USA-Mexico (CB750K4), 2003 - European Tour (CB750K4), 2004 - SOHC Easy Rider Trip (CB750K4), 2008 - Adirondack Tour 2-up (CB750K4) , 2013 - Tail of the Dragon Tour
2. CB750/810cc K2  - road racer with JMR worked head 71 hp
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Offline eurban

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Re: CB750 - Clutch lifter plate
« Reply #6 on: January 27, 2008, 01:47:40 PM »
When your remove the the springs and lifter plate assembly the clutch pressure plate (the thing with the four towers that the lifter plate bolts to) will be free to move towards the engine and unmesh from the teeth on the clutch center. You must make sure that when you intstall your new springs that the teeth on pressure plate assembly are properly engaged with the teeth on the clutch center.  You won't actually be able to see this but if you pullon the towers and wiggle clockwise/counterclockwise you can feel them move closer to you as the teeth are properly engaged.  When you tighten down the bolts do them a bit at a time checking to make sure that the lifter plate doesn't get cocked.  You must tighten the bolts all the way so that the lifter plate actually seats on the towers. If you didn't get the teeth meshed properly, it will not be possible for the plate to seat on the tower and you likely will snap off one of the corners of the lifter.   If you had completely taken apart the clutch assembly, it also would possible to install the pressure plate 90 degrees (or 270 for that matter) out from its original orientation.  Installed this way, the teeth on the pressure plate and clutch center cannot line up and again you would snap a corner off of the lifter if you tried to tighten things down all the way.  This is probably what many of those who have snapped the lifter assembly have done.  The factory manual (at least the one for my K8) suggests marking the orientation before disassembly.  180 degrees out will work fine BTW.  I don't have the torque spec for the four bolts off hand but they must be tightened properly; and again this means that the lifter plate and the towers on the pressure plate must come into full contact, with the tower fitting into the groove on the lifter. . . .Hopefully I haven't confused or scared you more!
« Last Edit: January 27, 2008, 01:54:10 PM by eurban »

Offline Tower

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Re: CB750 - Clutch lifter plate
« Reply #7 on: January 27, 2008, 01:54:26 PM »
I don't recall seeing any torque specs for those 4 bolts.  You're compressing the springs slightly, then tightening to a snug fit - sort of like very tight spark plugs.  For bolts going into a composite material like the clutch centre, I wouldn't apply too much torque (i.e maybe 15 - 20 ft.lbs, buts thats just a guideline).  The bolts (SH 5.8 class 6x20 1mm pitch ) will hold up to much more (up to 50 - 70 kg.m), but the clutch centre won't.
« Last Edit: January 27, 2008, 01:55:57 PM by Tower »

Offline Patrick

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Re: CB750 - Clutch lifter plate
« Reply #8 on: January 27, 2008, 01:59:43 PM »
If you only remove the star plate and leave the rest of the assembly alone you won't have to worry about the orientation of the pressure plate. Before you install the springs and start tightening the bolts, put the star plate back in without the springs and make sure it slides easily all the way in. You can get it 90 degrees off and it will snap a corner off the star plate when you tighten it. I won't tell you how many times I've done that. After you figure the right orientation, put the springs in and tightened the four bolts slowly and evenly. I like to do a criss cross pattern, one-half turn at a time. When you get them all flush remember that you are tightening steel bolts into an aluminum basket. DO NOT OVERTORQUE - the basket strips easily. Again, don't ask me how I know. Maybe five to seven pounds of torque, max.

It's not as hard as we make it sound, but it's easy to get it wrong. Take your time and if one bolt seems to be tighter than the others, pull them out and start over.

Patrick
1970 CB750 K0
1975 CB750K (new project)
1982 VF750S Sabre
1987 VT1100 Shadow
1979 Yamaha XS11
1969 Yamaha DT1B
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Offline eurban

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Re: CB750 - Clutch lifter plate
« Reply #9 on: January 27, 2008, 02:14:49 PM »
If you only remove the star plate and leave the rest of the assembly alone you won't have to worry about the orientation of the pressure plate.
While you don't have to worry about the pressure plate being 90 degree's out, you still need to make sure that the pressure plate is pulled towards you and engaged with the teeth on the center.  It is very easy to push the towers/ pressure plate towards the engine as you are taking things apart and putting on the new springs / starting the screws.  Sometimes the spring tension will eventually pull teeth into proper engagement and sometimes not.  Better to start off properly engaged . . . .

Offline KB02

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Re: CB750 - Clutch lifter plate
« Reply #10 on: January 28, 2008, 06:02:44 AM »
I think we have all broken that lifter plate at some point...

I broke mine twice... grumble... grumble... (that's not an exact quote of what I said at the time. ::) )
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Offline babyfood1217

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Re: CB750 - Clutch lifter plate
« Reply #11 on: January 28, 2008, 08:05:36 AM »
why is it that they seem to break often?  Are they die cast? sand cast? investment?  Could a stronger alternative be concocted, or is it just the nature of the beast?  I'm going to need to take mine off before the summer, and I would love to be able to reuse it...

-Chris
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Offline Patrick

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Re: CB750 - Clutch lifter plate
« Reply #12 on: January 28, 2008, 09:46:16 AM »
They only break when you do something wrong. I haven't broken one in quite some time now, despite working on clutches on several of my bikes. If you go slowly and carefully it shouldn't be a problem.
1970 CB750 K0
1975 CB750K (new project)
1982 VF750S Sabre
1987 VT1100 Shadow
1979 Yamaha XS11
1969 Yamaha DT1B
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Offline 736cc

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Re: CB750 - Clutch lifter plate
« Reply #13 on: January 28, 2008, 02:50:55 PM »
  Dude....

  They break because there's SPRINGS pushing against it and if you loosen or tighten incorrectly, pressure against plate is lopsided. Loosen or tighten each bolt 1 TURN ONLY EACH, 1 AT A TIME going around in sequence until they bottom-out. And those are little 8mm threads in aluminum, snug 'em don't crank them!

 
« Last Edit: January 28, 2008, 03:41:33 PM by 736cc »
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Offline lucky

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Re: CB750 - Clutch lifter plate
« Reply #14 on: March 16, 2013, 07:34:45 PM »
The way to keep from breaking that lifter plate is to lightly tap the plae continously as your tighten the 4 bolts. Tighten a little... tap tap tap tighten some more. etc.,.

Online scottly

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Re: CB750 - Clutch lifter plate
« Reply #15 on: March 16, 2013, 09:40:46 PM »
Uh-oh! Lucky is responding to 5 year old threads again. :o Must be 'shroom harvest season up there in the Redwoods...  ::)
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Offline ekpent

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Re: CB750 - Clutch lifter plate
« Reply #16 on: March 17, 2013, 05:13:10 AM »
I was wondering why Johnie would be asking that-Heck He's done at least three more great bikes since 2008  :)

Offline Johnie

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Re: CB750 - Clutch lifter plate
« Reply #17 on: March 17, 2013, 05:15:55 AM »
Eric...this post originated back in 2008. I am not asking the question. Someone opened up an old post I guess.
John
1969 CB750K0 - Candy Blue Green (current)
1970 CB750K0 - Candy Ruby Red
1970 CB750K1 - Candy Gold
1973 CB750K3 - Candy Bacchus Olive
1974 CB750K4 - Flake Sunrise Orange
2000 1500 SE Wing


Honda's owned in the past:
1965 65SS, 1969 CB350, 1971 CB350, 1972 CL175, 1972 CB350, 1974 CB450, 1975 CB360T, 1977 CB750K, 1980 CM400E, 1981 CM400C
Oshkosh, WI  USA

Offline ekpent

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Re: CB750 - Clutch lifter plate
« Reply #18 on: March 17, 2013, 05:23:44 AM »
Yeah Scottly noticed that and threw a friendly rib in. Trying to think if I can remeber what I was doing in 2008. Hmm  Heck what did I have for dinner last night   :)

 

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