GB500TT intermittent loud grinding noise in 1st gear?

**Nausea** · 6th March 2014, 12:23

My 1987 Honda GB500TT has a Intermittent problem where sometimes in first gear, it feels like I'm dragging a load & also from the gearbox comes a horrible scraping noise almost like I was dragging a heavy metal object over concrete.

I have to flick the gear lever up & down a few times to get rid of it. Most often the problem occurs if I've changed down into first from second but sometimes it will happen when going from neutral to first.

I've had the bike in a bike shop for a week but as Murphy's Law dictates, they cannot get the bike to make the noise yet it happens every time I ride it!

Any ideas what it could be?

Thanks

**Akzle** · 6th March 2014, 13:18

then it could have something to do with how you ride, innit, since it only happens when you ride it. Innit.

**BuzzardNZ** · 6th March 2014, 13:52

Plenty of grunt in those old things, just use 2nd instead.

**HenryDorsetCase** · 6th March 2014, 14:11

worn engagement dogs on first gear pair? worn shifter drum or forks or bent shaft? issues with the drum or forks usually cause jumping out of gear though.

is there metal in the oil? like gear tooth size? usually thats bad.

**Murray** · 6th March 2014, 19:26

Its stuffed - I'll buy the engine off you - how much???

**nzspokes** · 6th March 2014, 20:12

Put a new spring on ya stand.

**Nausea** · 6th March 2014, 20:54

Originally Posted by nzspokes

Put a new spring on ya stand.

Haha... it does sound like that but definitely not the stand scraping.

@HenryDorsetCase - there was no metal in the oil when it was changed just prior to Xmas.

Picked the bike up from the workshop today & went for a long ride & was able to get it to happen again. Most likely to occur if I change into second quite low in the revs & sounds like it is coming from the front sprocket area so will take the cover off & have a look for anything obvious.

Annoying, I have been accumulating parts to restore the bike & are nearly ready to go but don't want to pull it apart & then have to do so again at a later point in time.

**FJRider** · 6th March 2014, 21:23

Sounds more like clutch ... rather than gearbox.

Try 1st gear under load at low RPM .. then slowly increase revs .. (going uphill at the time shows it best)

**nzspokes** · 6th March 2014, 21:47

Well dont worry, what ever is jumping around in there will come out through the case soon enough. Then you will know.

**gammaguy** · 6th March 2014, 22:01

Na that won't happen

The gearbox will lock up, the bike will high side him and he will be so busy in hospital learning how to eat thru a tube and pee into a bag he won't worry about the bike anymore

Anyway it's harder to ride with only one leg

**Nausea** · 9th March 2014, 21:31

Originally Posted by FJRider

Sounds more like clutch ... rather than gearbox.

Try 1st gear under load at low RPM .. then slowly increase revs .. (going uphill at the time shows it best)

I think you're right, it doesn't go away when the clutch is engaged so can't be gearbox. It also briefly happened today just after I started the bike with it in neutral. The clutch doesn't appear to be slipping though.

**Paul in NZ** · 10th March 2014, 06:40

Is the electric start re engageing?

**actungbaby** · 11th March 2014, 08:59

Originally Posted by gammaguy

Na that won't happen

The gearbox will lock up, the bike will high side him and he will be so busy in hospital learning how to eat thru a tube and pee into a bag he won't worry about the bike anymore

Anyway it's harder to ride with only one leg

No it wont its called clutch lever i had bike lock up on me no dramas why the two stroke boys from 60,70srode with one hand over the clutch

Anyways gb 500s are not going be doing 120mph are they