Nasty engine noise, that goes when clutch pulled in ?!?!

[Dave h]

check the rivits that hold the clutch gear and bottom plate together.

[Scooterso]

J

Also noted that the gear cluster floats backwards and forwards on the input shaft by about .4mm; this is with either both casings put together, or just looking at it with the flywheel side taken off. Maybe this bit of floating is correct and required??!! Both the bearing and the needle rollers were all replaced. I can actually see (from the clutch side) the bearing moving away (by this .4mm) from the circlip which retains it??!! Is this correct

once gear cluster (spring gear) is installed, there should be no play once the nut is tightened down. should be rock solid. maybe the center spindle is the culprit? did you replace the ball bearing and needle rollers in it?

Ok, thanks again for your help and for confirming this. Yes, I replaced both the ball bearing and the needle rollers, to be clear it doesn't wobble, it literally just moves in and out the 0.4mm, but if it's supposed to be rock solid, then I'll take this apart and investigate further!

I also had a good look at the gearbox and how it meshed with the cluster, and noticed that when in neutral, and I was able to spin the rear axle/layshaft (without the cogs moving as well), it would appear as though the cogs were collectively all oscillating on the axle, as if the axle was bent, or the shaft they sit on was oval and worn??!! The gears also did this same oscillating when I removed the gear selector and rod, so I can elminate them as a problem. Surely, it must be almost impossible to bend an axle, then again, maybe it happened when he broke the gearbox, but I suppose wear of the layshaft that the loose gears run on is more likely, as they did seem quite a loose fit, compared with a Lammy engine, that I'm more used to??

I then took all the gears off the axle and had a good look at it, and slotted it back in the rear bearing to see if I could see if it was bent, but it's very hard to tell - I just wish I had another layshaft/rear axle to hand to try!

Any more thoughts on my recent findings would be appreciated, thanks

Im doing a p2 motor right now, and with new rollers and ball bearing, the spring gear has no back and forth play, it just spins in place and doesnt move otherwise.

the gs160 i had to change gearboxes needed a new axle as well, the broken gears chipped and damaged the axle.

did you check the gear box float shim? they need increasing in thickness with time as a lammy one does. think they start around 1.8 and go up in .2 increments (although every set of new shims Ive ordered the measurements are all over the place, so they dont seem to do them to that exact a measurement).
is it PX or PE? i.e. one end shim, or 2 shims at either end?

[Tom Russell]

Im doing a p2 motor right now, and with new rollers and ball bearing, the spring gear has no back and forth play, it just spins in place and doesnt move otherwise.

the gs160 i had to change gearboxes needed a new axle as well, the broken gears chipped and damaged the axle.

did you check the gear box float shim? they need increasing in thickness with time as a lammy one does. think they start around 1.8 and go up in .2 increments (although every set of new shims Ive ordered the measurements are all over the place, so they dont seem to do them to that exact a measurement).
is it PX or PE? i.e. one end shim, or 2 shims at either end?

Thanks for confirming this about the the cluster/spring gear, I will check this and find out why it has this small bit of play, with brand new bearings!?!?

I checked gearbox float, and this is all within tolerance. It's a T5 engine, and has 2 shims, one either end of the loose gears.

I'm going to have another look at these oscillating gears, and try and work out if it is the axle that is bent, shaft that the loose gears run on is worn, or maybe even something wrong with the rearhub bearing and/or the casing it sits in!?!?!

[mick1]

Thinking outside the box (excuse the pun!!)....could the noise be coming from the top end (crank/main bearings/piston slap/etc) the gearbox having problems may have caused damage at the top end....just a thought

[Tom Russell]

Thinking outside the box (excuse the pun!!)....could the noise be coming from the top end (crank/main bearings/piston slap/etc) the gearbox having problems may have caused damage at the top end....just a thought

Hi mate,

Thanks for your response.

Yes, I suppose there is a possibilty that there is a problem with the top end (crank twisted etc.), but the fact that the noise completely goes away when I pull the clutch in - so top end still spinning - makes me believe the noise is either coming from the clutch, or more likely the gearbox area.

Anyway, thanks again, really appreciate your input

[bazman]

If we're talking about the primary drive ( main gear which mesh with the clutch gear?) If so i also have play ( in and out , not excessive but there) and all my engines are sweet. Would discount this and look more at clutch? Cheers

[Tom Russell]

If we're talking about the primary drive ( main gear which mesh with the clutch gear?) If so i also have play ( in and out , not excessive but there) and all my engines are sweet. Would discount this and look more at clutch? Cheers

Thanks for confirming this mate

[Tom Russell]

Update - the layshaft/rear axle is most definitely bent and/or worn!!!!

All I can think is that this happened when the gearbox broke and the engine locked up!

Very odd, never seen anything like this; if it is actually bent (hard to tell) I would've thought that the casing would have given away, before the layshaft bent?!

In any event, new layshaft fitted and now NO oscillating loose gears so I'll finish off putting it all back together (including the new clutch pack and rebuilt cluster) and HOPEFULLY this nasty engine noise will have gone away, IF NOT ....................

I'll keep you posted

[Tom Russell]

All back together and NO nasty clunking noise anymore!!!!

So, must've been the worn/bent layshaft that was causing the problems. As said before, I've never seen, or heard, of this before, and it took three engine splits to work out what was going on!?

O well, all sorted now, thanks for everyones help and input.

Cheers,

Tom

[jonny snatchsniffer]

could be gear chatter especially if you have a lighter flywheel, how tight have you shimmed the box ?