Gearbox woes and WeeKend

[Mike Wilkins]

Long shot this but you never know, if it works could be interesting for all concerned.
Firstly, I was hoping to attend the last Devon WeeKend on my '89 para previously known as Torrey Canyon, as it had been to the first and others
BUT it has recently been exhibiting an intermittent road speed related cyclic graunch graunch when manoevering at slow speed in low gears. When pressing on you don't notice it. On centre stand in neutral nothing amiss, but in gear with clutch released mega clatter, only tried in first and second. Dropped oil looks like new, small amount of splintery dwarf and metallic powder on magnetic drain tit
SO Experts STEPTOE, ROB, BOB, what is it, output shaft bearing. ?? Or could it be clutch release or summat else

QUESTION. Is this something that could be addressed at the WeeKend
I have read various excellent gbox related threads so know I would have to buy up front everything likely to need replacing, and also make sure someone could bring the famous shimming plate, and get Sherlocks to provide a selection of shims

What's the score boys is this a goer ?

 

[flatdog]

Running it in gear on centre stand will most definately produce worrying noises. Don't confuse this with your road speed noise.

Lack of swarf in the Oil in box indicates not much if anything wrong.

Sounds like your tyre?

 

[B Murr]

If its road speed related, could it be the driveshaft joints shaft starting to come apart?

 

[Nutty]

Take the megamoto

 

[flatdog]

Is he still asleep?

 

[B Murr]

Put on centre stand and just rotate the back wheel while in neutral. I suspect you will hear the cyclic graunch graunch noise or something similar from the shaft. Do let us know what you find, even if our names so far are not Steptoes, rob bob etc.

 

[ChasF]

Just because you can't hear the noise at speed doesn't mean that it's good to ride down to Devon

 

[flatdog]

Put on centre stand and just rotate the back wheel while in neutral. I suspect you will hear the cyclic graunch graunch noise or something similar from the shaft. Do let us know what you find, even if our names so far are not Steptoes, rob bob etc.

Sorry, but what does that acheive. We all know (don't we?) they shouldn't be run in gear on main stands. Because of the 'catastrophic' sounding noises being produced - be it propshaft uj's or unladen clutches or rattling layshafts.
FFS don't do it. just it shouldn't be done.

Symptoms - has a 'general' graunch graunch feeling at low speed - disappearing in higher gears.

Findings, gearbox oil seems CLEAN with slight dusting of swarf on magnet and oil suspemded granuals = NORMAL USE..
= no issues due to the EVIDENCE.

Check wheels and diff next.

From what has been described, I certainly wouldn't be panicking just looking at tyres first.
What the fuck do I know it ain't mine.

 

[Mike Wilkins]

I think perhaps I've been a tit and imagined a problem worse than I have.
Am in Cornwall for the long weekend so will have another look on my return and report back

 

[Voyager]

It has recently been exhibiting an intermittent road speed related cyclic graunch graunch when manoevering at slow speed in low gears. When pressing on you don't notice it.

That could be a binding back brake, or some play in the rear wheel/bevel drive bearings.

On centre stand in neutral nothing amiss, but in gear with clutch released mega clatter, only tried in first and second.

On the centre stand, with the suspension at full stretch, the drive shaft angle is acute and the 'Hardy-Spicer'-type joints don't produce a constant velocity when off centre. Its going to complain .

Is it a gearbox bearing . . . ?? Impossible to say for certain from here.

I had one box sent to me where the owner wanted me to change the rear oil seal as he couldn't get the drive flange off the taper. I stripped the box to find it full of swarf, the front output shaft bearing's cage had come apart and the bearing was like a kid's rattle. Most of the other bearings were shot as well. He was obviously happy with the way it performed and just wanted to fix the oil leak .

If it feels OK on the road and it isn't producing swarf in the oil I would just ride it until something obvious presents itself. However, if its going to prey on your mind, remove the box and get it stripped and checked over.

Bob.

 

[solidstate100]

It could also be the front wheel bearings (front wheel off the deck, check for play and smoothness) or the front brake/disc which always has light rubbing contact - much more noticible at low speed.

 

[B Murr]

Sorry, but what does that acheive.

The achievement is testing whether driveshaft is culprit. "Rotate back wheel while in neutral" means rotate it with your hand as since its in neutral the engine cannot rotate it. If the UJ's are on way out a click click or even graunch graunch can be heard as the shagged UJs will not stay in place with their internal bearings shot. Its a simple test, no damage caused by it and I'd have thought anyone owning an airhead would be well advised to do this test when buying a bike at least. I believe that if you are on the move and the bearings decide to let go that you can cause serios damage to the swingarm so I'd be inclined to do this quick, simple, non destructive test.