Changing Front Sprocket...Need Help

[Chuckster]

I took the sprocket cover off to change the front sprocket on my GS550T and couldn't believe all the dirt and sludge built up in there. I literally had a mound of crap on the floor after I cleaned inside the cover and the sprocket area.

My question is this. The nut holding the sprocket on is already loose. I can turn it by hand. The only thing holding it on apparently is the washer which is bent up against the nut on a couple sides. Is the nut supposed to be on there "loose"? Or is it supposed to be torqued down? If so, how much? If I flatten out that washer, the nut would probably just screw right off. My Clymer manual shows the process to replace it, but doesn't mention how tight the nut should be.

[mushman]

There's probably a torque setting out there for your bike, If you get no replys, check the Suzy dealer. My bike's 1100 shop manual has a setting of 72.5-108.5 on a thread diameter of 25. Suzuki shop manuals should have the specs for your bike.

Mushman

[Billy Ricks]

Tighten it just about as tight as you can. You'll need a foot on the rear brake and the bike in gear to get things good and tight. Bend the washer over to keep the nut tight. Next time you check it it will probably be loose again. Just kind of happens that way. Some guys run Nylok nuts that won't back off.

[relic-rider]

It should be tightened to 36- 50 ft-lbs of torque. The bent over washer is a safety precaution in case the nut comes loose. It did its job. Take the nut off, clean up the threads and put her back on and tighten it up. Have someone apply the rear brake when you torque it. Check the teeth for excessive wear before you put it on.

[MelodicMetalGod]

Don't know what year your bike is, but I've got an 85 and the factory service manual indicates that the engine sprocket nut should be torqued 10.0 - 15.0 kg/m (72.5 - 108.5 lb/ft).

Best of luck!

[Chuckster]

Thanks guys! I really appreciate the responses. Anybody got any idea what size nut that is? I don't think I have a socket that big. My bike is a 1981 GS550T.

Also, why do they give you a range in torque settings and not just one number?

[gustovh]

How did you keep a chain on the bike with a sprocket like that, don't forget the rear, it is probably shot also.
V

[MelodicMetalGod]

Thanks guys! I really appreciate the responses. Anybody got any idea what size nut that is? I don't think I have a socket that big. My bike is a 1981 GS550T.

Also, why do they give you a range in torque settings and not just one number?

No idea what size that is. It would be metric, of course. If you want to just get the one socket, take a measurment or size it with an adjustable wrench and head to your favorite tool retailer.

I don't know for sure but I would guess the reason for a torque range is that a) there is probably not a single magic torque (you want it tight enough, but not too tight...thankfully perfection is not required) and b) if there was a magic number, it would be difficult to achieve something so precise as most torque wrenches are good at finding the range, but would have difficulty hitting a precise mark.

[Chuckster]

How did you keep a chain on the bike with a sprocket like that, don't forget the rear, it is probably shot also.
V

I cringe at the thought when I brought it home, it was running so I took it out for a spin and ran it up to about 60mph. Original chain too with most of the o-rings gone on it. Kind of ignored my MSF training for some instant fun. Glad it didn't cost me with a locked up rear wheel or broken chain. Somebody was looking out for me. It sure wasn't me.

Changing both the front and rear sprockets (and new chain).

[Chuckster]

No idea what size that is. It would be metric, of course. If you want to just get the one socket, take a measurment or size it with an adjustable wrench and head to your favorite tool retailer.

I don't know for sure but I would guess the reason for a torque range is that a) there is probably not a single magic torque (you want it tight enough, but not too tight...thankfully perfection is not required) and b) if there was a magic number, it would be difficult to achieve something so precise as most torque wrenches are good at finding the range, but would have difficulty hitting a precise mark.

Good idea about the adjustable wrench. Thanks! :-D

[JHawkins]

You want to be sure you get it on there good and tight, mine managed to back off, hit the sprocket cover and proceeded to rip the threads off the nut and the shaft. I never lost the nut or anything, not enough room for it to fall out. Unfortunately there was not enough left of the threads on the shaft to put a new nut on.

I ended up drilling and tapping the end of the shaft and putting a large washer on the end using an allen head bolt. After dremelling the cover to get clearance for the head of the bolt all seems well. Got over a 1000 miles on it that way now and as far as I can tell it is just fine. This was done the night before a 700 mile round trip to New Hampshire!

Now, that being said, I would not suggest my method, just put it on the way it should be done, keeping in mind that if you dont do it right you might have to go through the crap I did!

[Chuckster]

Just for anybody that may need to know, the nut size is a 32mm. I priced a socket at AutoZone and was $14.00! I also found a 1 1/4 inch size standard socket that was $5 which fit pretty much the same so I got that one.

[Calvin Blackmore]

31.7 mm is what 1 and 1\4 inches equals
mighty close