Clutch hub play, bearing wear, and clutch hub springs - HELP

[Chuck78]

In trying to diagnose an intermittent loud low speed knocking noise on a 77 GS550, as well as occasional failure to shift out of first gear, I pulled the clutch apart to inspect for a loose clutch hub nut and bearing wear, as advised by members here.

The first thing I noticed before removing the clutch hub was that I could grab the whole hub and wiggle it side to side a slight bit, and also could grab it and pull it in and out slightly, making a knocking noise at each in/out extreme. It seemed to me more play than this thing should have, if any. I am guessing 1+mm in and out. The impact took the clutch hub nut off effortlessly in a split second, and I believe the manual called for it being torqued 29-43 ft-lbs. I didn't have a clutch holding tool to take it off manually, so I couldn't really tell how little tension it actually had.

Is the basket supposed to have any of this play at all? Maybe I should replace the large roller bearing (can't remember, is there a thrust washer in there as well?)???? I might go back out real quick and try and reassemble it with the impact (search for "clutch hub tool" showed me that many people just reassemble it with an impact, no torque wrench possible that way) and see if it fixes anything.

Also, two of the springs held captive in the clutch hub are very loose, and two or three others seem like they are on the verge of rattling as well. I doubt these springs could make much of a knocking noise as this bike was making last season (only 160 miles this year, noise has not manifested yet), but I was hearing multiple rattling noises from all over the bike on a test ride today. Is it okay to grind off the rivet heads, shim all springs with identical washers to keep balanced even though they have various degrees of slack, and MIG weld the rivets back together?

[Chuck78]

I don't see any apparent or obvious signs of the large roller bearing set being worn, but there was some definite slop when assembled. Off to reassemble before sunset.

[hjfisk]

Clutch rattle on the 1000- and 1100 's is common and yes those springs can cause it, plus the basket moving around. Going through the same thing right now on one of my 1000's. I haven't seen it on a 550 but it is the same principal so it is very possible.

[tkent02]

What he said, usually it's the big bikes, I have never seen it on a 550 but who knows where it's been.

The loose springs can definitely cause knocking noise as they let the basket rattle around on the backing plate.

As a test you can bend each spring to make it longer. There's a writeup on Cliff's page. If the rattle stops you have found the problem.

What it needs is new springs or to shim the old ones so they are tight.

[Chuck78]

Alright, so I retorqued clutch hub after inspecting, so it definitely was not loose, but I still can grab the whole clutch hub/backing plate and move it in and out slightly (L->R if seated on bike). Looking back on it, I am now wondering if there is side to side play in the shaft going into the gearbox, which seems more likely now as I am thinking about it. Maybe this is normal, maybe not. Could be there are some thrust washers that need replaced??? maybe this is where the banging or knocking sound was coming from inside the gearbox, everything on the shaft being able to migrate side to side slightly out of place & slamming into other hard parts?????

This could be another excuse to tear apart the original '77 GS550B engine on the shelf and swap on that '81 GS650 cylinder/pistons/head with '89 GSX600F Katana BST31SS Flatslide carbs... Already have a head gasket oil leak excuse to bump the GS750B's spare engine up to 920cc 10:1!

if anyone can answer this question as to the play in an out of the entire clutch hub assembly, if that is common or considered normal, that would be very helpful. Next week I will have new clutch springs in for both bikes, so I will have the 750 apart and can compare. Too many projects halfway done right now, cleaning up removing dents from exhaust, rebuilding carburetors, fork seal on both bikes, steering stem needle bearings on one... Oh yeah & I also plan to grind off the clutch hub rivets and shim those springs and weld the rivets back in, hopefully that will make some improvements. Thanks everyone.

[tkent02]

This could be another excuse to tear apart the original '77 GS550B engine on the shelf and swap on that '81 GS650 cylinder/pistons/head with '89 GSX600F Katana BST31SS Flatslide carbs... .

OOhhh oohhh oh oh oh………

Do the carbs just pop right on? Same spacing and everything?

Need to check into this…..

[Chuck78]

carb sidenote for the 550-673cc swap

Yes they are very very close in spacing, I think I remember planning to ovalize the bolt holes in two boots and sliding them 1.5mm over and then port matching the boot& head with a dremel. I believe it was the 89&90 600 Katana's that used the non-slingshot Mikuni BST33 flatslides. The first two years (maybe '88-89?). After that they switched to the BST33 Slingshot style with phenolic slides and a much wider spacing that requires a lot of gsxr boot swapping & making spacers, as BoontownMike (cant remember his exact user name) has already done on his gs550. I actually got a set of those bst33's for the 550-673 project & they came with a set of parts carbs - the bst31's, & I then realized the 33's were a better fit for an 80 gs850 CV head that I have, and the BST31's were an almost direct fit for the gs650 head. If I get time, I can take a picture for you if you want. The jet sizes are much larger for the bst31 than the bst33, so I think they will be pretty close stock for a pods/pipes 673cc gs550 conversion.

[Chuck78]

http://www.thegsresources.com/_forum/showthread.php?t=149450&highlight=clutch+holding+tool

that thread gives me more pointers to the noise, and I will be tearing into the clutch backing plate springs within a few days. It also points out that the cam chain could be loose (has stock automatic tensioner though, and 8,000 original miles on 78 GS550 engine), and also could potentially be the cam end float knock that some GS's eventually make. Even at 8,000 miles in 36 years, I don't discount the potential amount of neglect and abuse even a low mileage engine could have seen in that amount of time.

Still looking for an answer on the in and out play in the entire clutch assembly with the hub nut torqued with an impact wrench.

[hjfisk]

http://www.thegsresources.com/_forum...h+holding+tool

that thread gives me more pointers to the noise, and I will be tearing into the clutch backing plate springs within a few days. It also points out that the cam chain could be loose (has stock automatic tensioner though, and 8,000 original miles on 78 GS550 engine), and also could potentially be the cam end float knock that some GS's eventually make. Even at 8,000 miles in 36 years, I don't discount the potential amount of neglect and abuse even a low mileage engine could have seen in that amount of time.

Still looking for an answer on the in and out play in the entire clutch assembly with the hub nut torqued with an impact wrench.

I beleive some in and out is normal. Have you tried what Tkent sugested? Try tightening the springs and putting it back together. It really is amazing howmuch noise they will make with bad springs

[Chuck78]

Have you tried what Tkent sugested? Try tightening the springs and putting it back together. It really is amazing how much noise they will make with bad springs

I have not looked into trying to sretch the springs out to take up the slop, but I will look into it that. I'm leaning more toward grinding off the rivets and shimming the springs with washers:

http://www.theflyingbanana.com/clutchhub.htm