Whirring/Whining noise from transmission region

[Flashmonkey]

Hey guys. I installed a new set of sprockets and a new chain on my 92 gixxer 750. I kept the stock gearing, but changed the chain to a 530 from stock (whatever the hell that was originally) with matching sprockets (both steel front and rear).

Anyway, now whenever I'm accelerating or cruising on the highway in 5th or 6th gear, i get this noticeable whirring/whining noise that seems to be coming from the transmission area of my bike. It resembles that gear driven cam sound from the old VFR engines. This noise wasn't there before I changed the chain and sprockets.

Some random googling has brought up the possibility of an aftermarket front sprocket being "noisier" than stock or "chain break-in". Not sure about any of this because this is my first full on chain and sprocket change. Any of you guys ever run into something like this? Both sprockets are JT and the chain is a DID 530VM.

 

[NP6000]

You didn't state the obvious ones, so:

Did you check chain alignment between front and rear sprockets? And by this I mean check using a straight bar method for chain alignment, not using the marked notches on the swing arm.

Is the chain is lubed well?

Break-in noise does sound plausible until the assembly "runs in" but chain mis-alignment sounds more likely.

Do you have the old sprockets? Check them for thickness and compare to the new ones.

Is there a shim or a shoulder on the front OEM sprocket?

 

[frekeyguy]

are you sure the sprockets are matched? all are 530?

did you lube your chain?

usually they shouldn't make any noise, I dont think i've noticed sound after a fresh chain install

 

[Flashmonkey]

You didn't state the obvious ones, so:

Did you check chain alignment between front and rear sprockets? And by this I mean check using a straight bar method for chain alignment, not using the marked notches on the swing arm.

Is the chain is lubed well?

Break-in noise does sound plausible until the assembly "runs in" but chain mis-alignment sounds more likely.

Do you have the old sprockets? Check them for thickness and compare to the new ones.

Is there a shim or a shoulder on the front OEM sprocket?

Yes, I did check the chain alignment after I finished installing the chain, which was Monday night. I haven't checked it since, but I'll do that today. On that note, though, I have the chain guard on. If the chain were still misaligned, would the chain not be rubbing up like hell against the plastic guard?

I should also have the old sprockets lying around, but the aftermarket sprocket was thicker...especially in the middle. Here's a pic of the JT sprocket:

The JT sprocket has a consistent thickness throughout, whereas the OEM sprocket was indented inwards in the middle where you put the nut on to lock it onto the spline drive. I remember looking at the two side by side and asking "sh*t...I wonder if this is going to be a problem?"

You think this could cause it?

are you sure the sprockets are matched? all are 530?

did you lube your chain?

usually they shouldn't make any noise, I dont think i've noticed sound after a fresh chain install

I'm fairly certain they're all 530 sprockets. I double checked the part numbers, and they did line up properly with the chain when I installed it. I'll double check again tonight, though.

I also lubed the freakin' hell out of the chain, and the master link when I put that on. When I had the bike on the rear stand I spun the wheel by hand and checked for any weird noises or to see if the chain and sprockets were binding at all. It all looked gravy at the time.

 

[frekeyguy]

I think the aftermarket front spockets don't have the little rubber bit..that the stock sprockets have. something like that, I can't recall right now.

take the chain guard off and see if its still making that sound.

Put the bike up on stands, take the front sprocket cover off and run it, and you'l be able to hear if its comming from there (BE EXTRA CAREFUL with fingers)

 

[skip]

There a plastic guard on the swing arm right at the front to protect it from the chain rubbing it? Is the new chain rubbing on it by chance? I have had this happen on a few chain conversions...

 

[Flashmonkey]

I think the aftermarket front spockets don't have the little rubber bit..that the stock sprockets have. something like that, I can't recall right now.

take the chain guard off and see if its still making that sound.

Put the bike up on stands, take the front sprocket cover off and run it, and you'l be able to hear if its comming from there (BE EXTRA CAREFUL with fingers)

This is my primary theory right now...that the OEM sprocket may have had a rubber gasket or something on it that I may not have noticed due to all the built up crap that was on it when I took it off.

I'll futz around with the chain guard and check the rotation of the front sprocket when I get home as well. And thanks for the reminder about the fingers

Skip, my bike doesn't have that. The only thing it could be rubbing up against would be the plastic chain guard.

If this is just a weird front sprocket/chain issue I'll be happy. That's a fairly easy and cheap fix. :happy3:

 

[Jayv]

are you sure the sprockets are matched? all are 530?

Mixed matched sprockets and chains cause a rattle not a whirring sound.

 

[Flashmonkey]

Ok...so i got the bike up on the stand. Apparently the chain was rubbing up against the chain guard, slightly....so I ripped that POS chain guard off. Not sure if this will have any actual effect yet...

I also made sure that the front and rear sprockets were aligned and that the chain wasn't binding up or getting caught on anything. It's all good there.

Then I ran the bike in first gear while up on the stand, with the sprocket cover off.....the whirring noise is definitely coming from the front sprocket. Not sure why it's making a sound. It does, however, sound like grease being whipped around....if that makes any sense. And yes, before I put the sprocket on, I put bearing grease on both the spline shaft, as well as the side of the sprocket facing the engine.

Ok so here's the question now: what the hell do I do about this?

What's the worst that can happen if I leave it this way?

 

[Skurj]

Is this a bigger chain than stock? Could it be rubbing on something else?

 

[ToSlow]

is there a front side of the sprocket when you put it on the shaft did you notice

 

[Flashmonkey]

Is this a bigger chain than stock? Could it be rubbing on something else?

No, the stock chain was close in size, if not slightly wider.

is there a front side of the sprocket when you put it on the shaft did you notice

No, the sprocket was the same on both sides, except one side had a "JT" stamped on it...i dubbed that side the front.

I took a pic of the stock sprocket:

Notice how it ridges inwards near the centre, and by the outer edge. Compare this to the JT sprocket, which is sorta like this:

I'm scouring google and the gixxer forums for an answer. Let me know if you guys come up with something.

 

[ToSlow]

did you check the width of the sprocket? is there a shim or something that is missing.

 

[Flashmonkey]

did you check the width of the sprocket? is there a shim or something that is missing.

No, there was no shim that I saw...and unfortunately I didn't measure the width of the new sprocket before I put it on. I was watching the sprocket spinning under load and both the chain and the sprocket were moving freely and without any apparent obstruction.......aside from the slight whriring noise, nothing seemed out of the ordinary.

 

[ToSlow]

No, there was no shim that I saw...and unfortunately I didn't measure the width of the new sprocket before I put it on. I was watching the sprocket spinning under load and both the chain and the sprocket were moving freely and without any apparent obstruction.......aside from the slight whriring noise, nothing seemed out of the ordinary.

if it was me i would pull it apart and recheck it for uncommon wear. try the front sprocket in the chain when it is a part. imo

 

[Flashmonkey]

if it was me i would pull it apart and recheck it for uncommon wear. try the front sprocket in the chain when it is a part. imo

Ya I think i'm gonna do just that. At this point there really isn't anything else to check for haha. Thanks for the help!

 

[sinbin]

So the grease sound I think is the typical sound the chain makes on mine if it's on the rearstand and in gear, but I cannot hear it while riding at all.

The JT is overall a slimmer sprocket so I think will be the same offset compared to the wider and indented stock one.

Typically the top gear does make a whine if I'm at a lower speed but over 50 kph there is nothing noticeable. If the older chain was a 520 conversion then perhaps the heavier chain is causing a bit more noise? - EDIT: sorry I just saw you had already compared so it was not a 520

I'm sure you've already checked this :
Is the chain slack ok? Perhaps it is too tight?
The rubber guides on the swingarm, is it in place above and below?
When you put the kickstand up, does it get anywhere near the chain?

Watch it without the chain cover, all that grease is going to find a home on your rear rim

I hate to throw this into the mix, but does it sound like the drone of a worn bearing?

 

[Flashmonkey]

I hate to throw this into the mix, but does it sound like the drone of a worn bearing?

Yea I've checked everything else you mentioned....in some cases twice. I'm praying like hell that it isn't a transmission bearing. I'm pretty damn sure I put that front sprocket on right. Failing to find any fault there, my next step would be to take a look at the clutch and see if any parts are worn. I did notice some weird slipping and odd clutch characteristics today....so a messed up clutch is likely....but it could also be that i f'd up the countershaft bearing while either removing the stock sprocket or installing the new one (I took off the nut and torqued it back on by putting it in gear :snorting. To be honest, when I first heard the noise, a busted tranny bearing was the first thing that came to mind....as I have had prior experience to busted car trannys before.

Well...onto the trouble shooting haha. This is going to be an interesting season.

 

[sinbin]

Yea I've checked everything else you mentioned....in some cases twice. I'm praying like hell that it isn't a transmission bearing. I'm pretty damn sure I put that front sprocket on right. Failing to find any fault there, my next step would be to take a look at the clutch and see if any parts are worn. I did notice some weird slipping and odd clutch characteristics today....so a messed up clutch is likely....but it could also be that i f'd up the countershaft bearing while either removing the stock sprocket or installing the new one (I took off the nut and torqued it back on by putting it in gear :snorting. To be honest, when I first heard the noise, a busted tranny bearing was the first thing that came to mind....as I have had prior experience to busted car trannys before.

Well...onto the trouble shooting haha. This is going to be an interesting season.

^Yikes!
Well lets hope it's the front sprocket being the wrong pitch or something...
Could you post up a youtube vid of the sound?
Best of luck!

 

[Flashmonkey]

^Yikes!
Well lets hope it's the front sprocket being the wrong pitch or something...
Could you post up a youtube vid of the sound?
Best of luck!

Ya i know....not the smartest move ever, but I wasn't exactly hammering on it hard either. Even tightening the nut back on, I didn't use excessive force. I'd like to think that the engine would put more force on that component than I ever could by hand.

The vid isn't a bad idea either. I'll hook up my camera and see if i can catch it. Might not be until the weekend, though.