Alternator Plates

[twinegar]

I'm not finding what I need doing a search so I will start a discussion about something that has probably been knocked around before.
I have a new set of Alternator plates coming and want to know if I should re-dress the face of each one or just mount them up? Someone told me the faces aren't flat and that flattening is a good idea. They also said to place a washer behind the spring to increase tension. I prefer to trust that Honda engineers knew what they were doing and just leave things oem but if long time CBX'ers have a better idea I want to hear it.

[NobleHops]

I'm not finding what I need doing a search so I will start a discussion about something that has probably been knocked around before.
I have a new set of Alternator plates coming and want to know if I should re-dress the face of each one or just mount them up? Someone told me the faces aren't flat and that flattening is a good idea. They also said to place a washer behind the spring to increase tension. I prefer to trust that Honda engineers knew what they were doing and just leave things oem but if long time CBX'ers have a better idea I want to hear it.

Here are a few links for you Tom:

viewtopic.php?p=3675&highlight=

http://www.motorcycleproject.com/motorc ... lutch.html

http://noblehops.smugmug.com/Motorcycle ... 222pj-A-LB

This is the best of the four - including sage advice from our Technical Dave McMunn and Mike Nixon, plus a couple of links and photos of mine before and after:

http://www.cbxworld.com/modules.php?nam ... highlight=

N.

[twinegar]

Thanks for the links.
I emailed you to see how you wanted me to ask questions and comment at your sight and didn't hear back. Did your spammer catch the links on the bottom of my mail possibly?

[twinegar]

I added the content from the links to digital notes applied to the main charging system page in the PDF shop manual for safe keeping and would suggest to members to do the same with any useful info garnered here. Later just click the note icon and the saved material pops up.

[Jeff Bennetts]

I haven't seen a set of new OEM plates for a while but just in case Honda hasn't already addressed this make sure the oil slot edges in the plates aren't sharp, if so champher them a bit with some wet sand paper so they don't scar the plates upon start up.

[twinegar]

Will do, I will check them after I true up the surface.

[twinegar]

The plates were nearly perfect so I sanded the face some and mounted them. The regulator was toast so I installed a used one and all is well for now.

[NobleHops]

The plates were nearly perfect so I sanded the face some and mounted them. The regulator was toast so I installed a used one and all is well for now.

Does 'perfect' mean they were 'flat'? If you put a truing bar across mine and shone a light behind it you could clearly see they were conical in shape. That was the meat of the matter in the technical bulletin Honda issued: They were not flat and so were prone to slipping much more than they were designed to and when the spring wore they were prone to overheating.

Pics, and apologies that they were not more carefully photographed in the same way, but you'll get the idea:

Before:



After (lapped on a chunk of granite with emery cloth):




N.

[twinegar]

They were true blue and flat too!
I went ahead and ran both over sandpaper on the bed of my table saw and confirmed flatness. How can I tell if the tension spring needs a shim? At idle the meter drops to 12 and when I take off and cruise at 30 - 40 mph the meter doesn't climb to 13.2 for a few seconds. I also get the impression of slipping at a stop with break light and turn signal on. I just get the impression that the plates are slipping when they shouldn't. I am comparing it to my 79 that seems to charge more efficiently. Should I shim it 1/8" and see or how much?

[twinegar]

.............and yes I did use a straight edge to check for flatness.

[kbart1]

hey guys

i have a question re the alt. clutch coupling plates. my alternator is off the motor. springs washers spring seats all out on the bench. in reading the manual it appears that the clutch plates should easily separate? I'll call it coupling "B" appears to be bolted to the alternator shaft while coupling "A" appears to be under pressure against "B" by the spring etc. my plates WILL NOT SEPARATE and they almost appear to have kind of a rough texture to the outside of them, almost like someone poured oil over a grinding stone for example. also, when i removed the clutch from the case there was what appeared to be a "metallic" sludge stuck to the case below where the plates spin? i should mention this is an "81 but i think they are all pretty much the same??? any thoughts?

thanks a lot!
kent

[twinegar]

Do you need a PDF of the shop manual? I only have the 79/80 manual but it will cover your mechanical issues closely. The blow-up drawing below might help some. I guess it's possible that someone slipped the plates enough to weld them together or maybe deliberately welded them or maybe used something like JB Weld to stick them together. Once you go over it and see what needs replaced I can point you at a new set of plates or what might be missing in the alternator assembly. Keep an eye on Ebay and pick up a good used rectifier just in case. Prices are beyond ridiculous on new and used CBX parts and they are only getting worse so jump in.

[daves79x]

I have seen the plates welded together (on purpose) before. Any evidence that they are welded? The solid coupling idea is OK except for one thing - there is no cush drive in between to handle any side-to-side movement. Welding up the clutches would likely be pretty hard on alternator bearings since there is no allowance for any play that may exist. At this point in time, plates are NLA from Honda and guys are getting a fortune for leftover new ones that they may have. Best bet is to watch eBay for used stuff but you may have to buy a whole spare alternator to get the plates, and often the drive plate is not included. Not a bad idea to have a spare around, however. Or go the conversion route.

Dave

[Jeff Bennetts]

The reason Honda went to the clutches was so the inertia built up by the mass of the spinning alt assembly during accel and decel wouldn't twist the input shaft.

I think its time to find an after market vendor to start making these.

[Don]

At idle the meter drops to 12 and when I take off and cruise at 30 - 40 mph the meter doesn't climb to 13.2 for a few seconds. I also get the impression of slipping at a stop with break light and turn signal on. I just get the impression that the plates are slipping when they shouldn't. I am comparing it to my 79 that seems to charge more efficiently. Should I shim it 1/8" and see or how much?

Since this is an old post, you've probably already resolved your issues, but the following may be helpful to anyone still diagnosing a clutch slippage issue, so I'll add it here

At idle the alternator cannot put out enough to keep up with the headlight, so the voltage falls a bit and the battery makes up the difference - The regulator also goes to full on and the clutch plates cannot handle that torque load at lower RPM's

I think if you could chart the clutch slippage you would find that at any RPM lower than 3,000 to 3,500 the clutches cannot handle the alternator torque with the regulator in the full on mode. Accelerating away from a 30 or 45 second idle situation while sitting at a red light, it does not take the alternator long to put back what the battery used keeping up with the headlight, so the clutches do not slip for very long, especially if you maintain RPM's above 3K while the battery is charging. In normal everyday riding, the regulator is seldom in the full on mode, so the alternator isn't working at max capacity and slippage shouldn't be a problem . . . . unless you've added extra lighting or are using heated gear or have some other aftermarket load on the electrical system - Clutch slippage could be a big problem if that's the case

If you have a CBX which is a bit hard to start, the slippage will be more severe and last longer while the alternator recharges the battery to replace the amperage used in starting - The alternator may be locked in full on for several minutes and the clutches may slip some all the way to 5,000 RPM or so, but once the battery is fully charged things will return to normal

Alternator performance is something I've studied for quite some time. I have an electronic voltmeter which gives a colored LED indication of the system voltage so I have a pretty obvious indication of when it appears the clutches are slipping, how long it lasts and what part engine RPM plays in the equation

Shimming is tricky - You cannot put too much shim under the spring before it is coil bound and that would put quite a load on the bearings. (The spring is pretty close to fully collapsed in the stock configuration . . . . too much shim will make it a 'solid' with no further collapse possible) I suspect 1/8th inch might be a bit too much. From my experience shimming 30 to 40 thousandths makes quite a difference in how much or little your clutches slip. If you intend to shim, I would start there and make note of the difference in alternator performance . . . . a little shim may be all you need

Don