Triumphrat

trumpy37 · 01-07-2009, 07:54 PM

Hi guys

I picked up my ST3 last month and had been going really well until it developed a rattle at the 300mile mark. It sounds exactly like jiggling 2 keys together or a loose washer. Although I'm not 100% sure it appears to be coming from the front.

Needless to say I have taken it to the dealer and they don't seem to have any clues.

Here's what happens

1. Everytime I go over a small/large bump or any slightly rough surface on the road I hear the rattle. It can be continuous if the rough surface is long.

2. It happens even if the engine is turned off ( I tested going downhill).

3. I have checked a million things on the bike and can't seem to find anything. Checked all visible screws, footpegs, exhaust and fittings, removed handlebar and jiggled, removed front section (i.e instrument panel, headlight, screen) and jiggled, removed airbox cover and checked inside and can't find it.

4. It doesn't happen when bouncing the forks or rear suspension when the bike is stationary.

It's driving me insane as I keep hearing it all the time at any speed unless the road is perfectly smooth. I had a pillion the other day and they could hear it as well.

Any thoughts, suggestions would be greatly appreciated!!

Thanks in Advance.

Diego · 01-08-2009, 01:01 AM

That's a puzzler, and all I've got at the moment are a couple of thoughts at random. First, and by no means intending to be insulting... you're sure it's not actually the keys rattling together, or one of them bouncing against the handlebar? If it's not that, have you looked everywhere under both the seat and tank for anything loose or bounceable... including the "tool kit" itself (the 5mm Allen key and the tank prop rod)?

One important note of caution--when testing, try to avoid coasting downhill with the engine off! These gearboxes depend on the oil system being pressurized in order to have adequate lubrication. Old-timey transmissions ran with the gears sitting in a bath of relatively thick gear oil, and thus pretty much always had enough oil film on gears and bearings, whether the engine was running or not. These, however, depend on a continuous flow of much lighter engine oil passing through carefully engineered channels in order to maintain sufficient film on critical parts.

MacBandit · 01-08-2009, 01:33 AM

Quote:

Originally Posted by Diego

........One important note of caution--when testing, try to avoid coasting downhill with the engine off! {etc}

I really doubt that would ever cause a problem as the transmission would be totally unloaded so what oil that's still in there should be more than sufficient.

MacBandit · 01-08-2009, 01:35 AM

Something to check. I've seen and heard of a number of bikes lately 2 were KTMs and one was a BMW that came from the factory with either very little or even no fork oil in one or both fork legs. If it had none then it would be pretty obvious but if one was left dry you probably wouldn't notice it unless you got the oil in the one fork hot enough to lose it's viscosity.

Diego · 01-08-2009, 02:29 AM

Quote:

Originally Posted by MacBandit

I really doubt that would ever cause a problem as the transmission would be totally unloaded so what oil that's still in there should be more than sufficient.

No, probably no problem for the very occasional, very short test glide--but would you really want to risk "ever"?

Load or no, even the simple act of gear teeth meshing and unmeshing quickly becomes a source of friction as the film of relatively thin oil gets squeezed out from between them with repeated engagement; not to mention bearings and seals, which could take a bit longer to show effects of oil depletion but are not immune from them. The cautionary notice against coasting with the bike out of gear is standard in Triumph manuals, and has science and good sense behind it. Hence my own note of caution... not a decree that it means instant and certain doom, but merely a reminder that coasting down a long hill and/or doing it repeatedly would not be the wisest course of action.

trumpy37 · 01-08-2009, 03:14 AM

Good point Re turning engine off. It was only for around 10-15meters so I'm hopping that wouldn't be enough to do any damage.

As for keys rattling, yeah that's EXACTLY how it sounds and that's the first thing I did by removing all but the ignition key from the barrel.

When I bounce the forks I don't hear anything so I'm assuming that's not it.

I wonder if anything can be stuck within the frame itself, there's a few holes where things could get in or left behind at the factory. Who knows, I'm clutching at straws here.

doggy675 · 01-08-2009, 10:20 AM

Somebody else had this exact problem and it was 2 small stones stuck behind the exhaust headers.

Diego · 01-08-2009, 01:52 PM

Your memory is way better than mine, doggy.

Yes, that can definitely cause the symptoms described.

wally666 · 01-08-2009, 03:12 PM

i noticed the same thing. i thought it was from the front too, but now i think its the clips that hold on the foot pegs, since i took off the passenger pegs i don't notice it anymore.

trumpy37 · 01-11-2009, 03:33 AM

I finally figured out what the noise is. Well sort of.

Although it sounds exactly like a rattle when you're on the bike (with the helmet on) it's actually a SQUEAK. I had someone stand near a rough surface on the road and listen to it.

It's less apparent when you have a pillion on. It's almost 70% better.

I can easily replicate the noise by simply banging (gently) on the pillion part of the seat with my fist. It won't do it if I bounce the rear shock whilst I'm sitting on the bike.

I'm guessing it's something to do with the frame or some linkages somewhere which haven't been greased properly at the factory.