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Author Topic: CB750 - Clutch lifter plate  (Read 10258 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...
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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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Offline 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 »
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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 »
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1970 CB750K0 - Candy Ruby Red
1973 CB750K3 - Candy Bacchus Olive or Sunflake Orange
1970 Chevy Chevelle SS396 - Cortez Silver
1976 GL1000 Sulphur Yellow

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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
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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 »
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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 »
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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
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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 »
Quote from: Patrick 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.
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 . . . .
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Offline KB02

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Re: CB750 - Clutch lifter plate
« Reply #10 on: January 28, 2008, 06:02:44 AM »
Quote from: andy750 on January 27, 2008, 01:15:18 PM
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.
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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.,.
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Offline 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  :)
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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.
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1970 Chevy Chevelle SS396 - Cortez Silver
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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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Offline 74CB750Chopper

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Re: CB750 - Clutch lifter plate
« Reply #19 on: June 29, 2016, 07:59:23 PM »
Well I just broke my 3rd lifter plate. I must be very special. Those things cost about $60 and I can only find them in Germany. It will be a month before I can break the next one..... :'( This build is never going to be done....
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Offline Jerry Rxman Griffin aka MuthaF'er

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Re: CB750 - Clutch lifter plate
« Reply #20 on: June 29, 2016, 08:11:39 PM »
I was luckier. My last replacement went in fine. I made sure it was oiled so it would slide in without binding and I used my dental mirror to ensure that all 4 springs fit outside the 'slot' and mounted on the inside and outside perch and did not get pinched. I believe that was what broke it's predecessor when I carefully tightened opposite pairs a half turn each. Do NOT forget to observe the springs orientation!

Here you go. $30 Buy It Now with the bearing. I simply searched "CB750 clutch lifter plate". His used one is better than your used one LOL.

http://www.ebay.com/itm/CLUTCH-LIFTER-PLATE-1972-HONDA-CB750-FOUR-CB-750-72-/142040648630?fits=Model%3ACB750&hash=item2112484bb6:g:gkIAAOSwbYZXdEqa&vxp=mtr
« Last Edit: June 29, 2016, 08:14:19 PM by Jerry Rxman Griffin aka MuthaF'er »
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Offline scottly

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Re: CB750 - Clutch lifter plate
« Reply #21 on: June 29, 2016, 08:31:52 PM »
Quote from: 74CB750Chopper on June 29, 2016, 07:59:23 PM
Well I just broke my 3rd lifter plate. I must be very special. Those things cost about $60 and I can only find them in Germany. It will be a month before I can break the next one..... :'( This build is never going to be done....
Probably 99% of broken lifter plates are caused by misalignment of the hub splines. There are two ways that these parts fit together that are right, and two ways that are wrong.
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Offline scottly

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Re: CB750 - Clutch lifter plate
« Reply #22 on: June 29, 2016, 08:41:21 PM »
Quote from: eurban on January 27, 2008, 01:47:40 PM
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.
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Offline NEDBUCK1@outlook.com

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Re: CB750 - Clutch lifter plate
« Reply #23 on: July 20, 2022, 06:52:32 AM »
Hi - I broke mine too - but I have welded the corner back on!?!? it seems pretty strong - anyone else done this? Am I fooling myself - will it last?
Thanks
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Offline MauiK3

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Re: CB750 - Clutch lifter plate
« Reply #24 on: July 20, 2022, 08:17:41 AM »
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