stays crunchy even in milk

[Anonymous]

So here's my problem. My '77 GS 550 has this crunchy grinding noise coming from somewhere in the gearbox region when she's coasting in gear. Accelerate and the grinding vanishes. Pull in the clutch, goes away mostly. I noticed a real increase in this from nill to loud when I put a new chain on, one that didn't have three inches of slack. So when everything is tight, something's grinding. Anyone else ever have this problem? Time to replace things? I'm really uptight about this since the last time I rode the bike it clenched up (we're talking LOUD crunchy grinding noise) at about 30mph and I just about dumped it. Now I refuse to ride it until I know what's going on. Any ideas?

[WifeofDink]

It is possible the gearbox bearing needs replacing, if you have movement in the countershaft then this would suggest that the bearing is shot and this could be your grinding noise.

[moto_dan]

Re: stays crunchy even in milk

I noticed a real increase in this from nill to loud when I put a new chain on, one that didn't have three inches of slack. So when everything is tight, something's grinding. Anyone else ever have this problem? Time to replace things?

If you didn't replace your sprockets with the chain replacement, I would suggest that you need to replace the sprockets. Look carefully at the sprockets and you'll probably notice some misshaped teeth. It is usually recommended to replace as a set, chain and sprockets. Did I use replace enough times?

[HiSPL]

Put your bike on the center stand and spin the rear wheel by hand. watch the chain go round and notice 2 things; 1 your chain has some stiff/rusted links and they don't like to bend around sprockets. 2 you probably have worn sprockets that amplify problem #1. Also check that your sprockets are lined up side to side. easiest way to do this is without the chain on place a straight stick against the rear sprocket and see if it points to the general vicinity of the countershaft sprocket...

last chain I bought was a cheap jcwhitney masterlink chain. It makes grinding noises too if I don't keep it absolutly drenched with PJ1. Try lubing the chain really good and see if it goes away. also run with a little more slack in the chain. If I get my chain to tight it grinds also..

Good luck

[Anonymous]

Must admit, sound like a bearing to me. Remove the chain and start the engine. Put it into gear, then let it idle in first gear. Does it still grind ? If so, your problem is not the chain as suggested. If the grinding dissappears, let the bike idle in first with the chain on (on its centre stand). Does it grind ? Listen very, very carefully to the grinding and decide wether its in the gearbox or the engine. Is it main bearings ? Correct me if I am wrong but I thing the mains in the GS are roller bearings. I know what they sound like when they collapse. They make a bad grinding noise. It could be bad so you are right not to ride it until it is fixed. However, good news is these engines are very simple and easy to work on. Worst case scenario is main / big ends. Two of you will have them done in a weekend. If its gearbox I am fortunate never to have needed to work on one so I can't offer any advice here. Be patient, take your time and assess the problem in a logical manner, you will fix it.

[Anonymous]

crunch fix

After consulting the handy dandy trouble shooting index in my Haynes and considering everyone's hints, I'm guessing at the 5th gear pinion. Mianshaft or layshaft I don't know. When I put it on the center stand and shift by hand I get the same result. Feels like it's "searching" for a positive shift and is ratcheting between gears. Almost definately gearbox, whatever the exact fix. Out comes the engine...

[Anonymous]

FIRST... try loosening your chain... maybe its too tight.. I had a guy describe all the same symptoms you did .. (hard to tell without being there and listening/trying it)... I figured for sure it was the countershaft output sprocket bearing...

Turns out he had neglected to mention he had just adjusted the chain before the noise started...... after he loosened it up... the noise went away.

..... try that first.... its worth a try... many novices adjust their chains wrong.

[moto_dan]

Re: crunch fix

After consulting the handy dandy trouble shooting index in my Haynes and considering everyone's hints, I'm guessing at the 5th gear pinion. Mianshaft or layshaft I don't know. When I put it on the center stand and shift by hand I get the same result. Feels like it's "searching" for a positive shift and is ratcheting between gears. Almost definately gearbox, whatever the exact fix. Out comes the engine...

Are you shifting through the gears with the bike running or spinning the rear wheel? If not, then then going through the gears will not be be "positive". Again I ask, did you replace the sprockets with the chain replacement? Have you removed the chain and tested the transmission? Unless severly abused I will be very surprised if its an internal transmission problem. Always IMO

[Anonymous]

Re: crunch fix

Are you shifting through the gears with the bike running or spinning the rear wheel? If not, then then going through the gears will not be be "positive". Again I ask, did you replace the sprockets with the chain replacement? Have you removed the chain and tested the transmission? Unless severly abused I will be very surprised if its an internal transmission problem. Always IMO[/quote]

The engine was running when I was shifting through the gears. So far, I've left the chain on to check it out. I've put two new chains on, once when I got the bike two years ago and again at the beginning of this season, w/o chainging any sprockets. Had the bike gone over at a reputable shop after getting it and heard nothing about sprockets needing changed, they gave it a thumbs up. As this is my first, I'm still not hip to all the maintenance details. My riding style is not abusive, just the occasional goose. Cruisin' around town and a 100 mile day now and then. Will the drive chain skip if it needs lubed? My chain lubing routine could be improved. I ran with a touch less tension than spec so can I rule out too tight of a chain? I'll take the chian off and test it and keep ya posted. Thanks

[moto_dan]

Two chains replaced and no new sprockets At the least you need new sprockets. Putting a new chain on old sprockets will accellerate wear on your new chain and cause all sorts of funny noises from the drive train. Look closely at the teeth of your sprockets and I'll bet the teeth are misshapened.

[Dink]

I have gotta agree with Dan on this you cannot possibly have replaced two chains without needing to replace the sprockets. In fact drive chain and sprockets MUST be replaced as a set.Did this noise exist before you replaced the chain,if not that is your problem.
Dink