R80/7 - Whats that noise?

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Ishamwolf
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R80/7 - Whats that noise?

Postby Ishamwolf » Sun Jun 18, 2017 3:49 pm

Hi , Hope someone can help me - I was merrily minding my own business up the M6 last week on my 1979 R80/7 , when I heard a whine from down below. I thought it was the road surface, but then a scrape / grind noise scared me to bits . I closed the throttle and all was quiet, so trundled on the hard shoulder at 20mph. Its hard to say if the whine noise came back when I pulled the clutch in , sometimes it did , sometimes it didnt, but I managed to limp home 30 miles at about 25mph. If I went faster, the noise would come back and go again.
I just started it up in my drive a week later. sounds fine in neutra, except trace of a whirring , back of the engine block. If I pull the clutch in, it disappears. Does this sound like I need a new clutch , or something more sinister ? Many thanks

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Galactic Greyhound
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Re: R80/7 - Whats that noise?

Postby Galactic Greyhound » Sun Jun 18, 2017 4:11 pm

Starter Motor pinion not retracting from the Flywheel ring gear?

Is the gearbox oil level OK?

With the rear wheel kept off the ground, try going up and down the gearbox to see if the noise occurs over all the gears and if it can be isolated using a listening stick.

Is the Clutch adjusted correctly?

Are the wheel bearings OK?
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" onclick="window.open(this.href);return false; - It works!

Ishamwolf
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Re: R80/7 - Whats that noise?

Postby Ishamwolf » Sun Jun 18, 2017 11:30 pm

Great , thanks - just drained the gearbox oil - about 800ml which looks like the minimum- cant say when it was last ever done.
Thasnks for the advice Greyhound :)

bob
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Re: R80/7 - Whats that noise?

Postby bob » Mon Jun 19, 2017 2:48 pm

There is a good chance that what you heard was one of your gears trying to climb out of the gearbox due to a collapsed bearing. It happened to me: a bit of a grinding screech when accelerating. I drove slowly home and stripped the gearbox. There were only three balls left in one of the ball bearings. Be safe, check the gearbox out.
'78 R100RS, '58 Norton Model 50, (both current), '83 R100RS, '02 850GS,

Ishamwolf
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Re: R80/7 - Whats that noise?

Postby Ishamwolf » Mon Jun 19, 2017 8:23 pm

I appreciate the post Bob. thanks - that sounds exactly like what I experienced. I can change spark plugs ok, but this one looks a bit daunting for me, plus , I just found out Mr Boxer in Leicester has retired !...I may need a bottle of Manup & a socket set. Thanks.

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Re: R80/7 - Whats that noise?

Postby John Marshall » Mon Jun 19, 2017 9:49 pm

I had a gearbox go once,preceded by a noise like a cat in a liquidiser.Then a horrid clunk and l limped back in whatever gear I ended up in.But good because when it failed I was doing 25mph but just half an hour before I was tanning the thing (R100RS). I would think you can either try get it rebuilt,rebuild it yourself (see http://jhau.maliwi.de/mot/gearbox.html) you will require a puller making up and end plate to reshim and it can take a LOT of effort to break the UJ flange of its taper, or just get an exchange one and have done with it. Bearing in mind (sorry for the pun) it is the riding season I'd probably go with the latter. I have piles of bits of gearbox,testament to the failure rate.
Anyhow drain the gearbox oil and look at it for metal.
good luck.

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Galactic Greyhound
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Re: R80/7 - Whats that noise?

Postby Galactic Greyhound » Mon Jun 19, 2017 10:09 pm

Following on from bob's post;

Don't assume it is gearbox failure without checking it out and being absolutely sure!

Did you check the colour state of the gearbox oil?
Bearing breakup is usually accompanied by tell-tale traces in the oil such as a gold fleck colour due to brass bearing cages etc. being ground up.

If you still have the drained oil, run it through a filter (sieve) into a basin.
You can then check the colour and also see if any debris is held in the filter.

If the gearbox oil drain plug is underneath the gearbox, then any small debris (broken cages, ball bearings etc) has a better chance of being flushed out on draining.
If the drain plug is on the side of the gearbox, then debris could still be trapped inside.

You might try using a telescopic probe with a magnet on the end through the Drain and Fill holes to see if any ferrous material such as ball bearings can be fished out.
It wont work with non-ferrous material such as brass cages etc. and a telescopic 'grabber' tool might be used in this case if any debris can be seen.

You can get these telescopic probes cheaply on Ebay and they are a good addition to a toolkit.

Here are some useful links:

Motorworks - Used Gearboxes: https://www.motorworks.co.uk/vlive/Shop ... 0_20_DA_35

James Sherlock - Repair of pre 1981 Gearboxes: http://www.james-sherlock.co.uk/shop/r4 ... e-exchange

Snowbum - 4 & 5 Speed Transmissions: http://bmwmotorcycletech.info/transmission.htm
Joergs Motorcycle pages - R Series Gearbox Overhaul: http://jhau.maliwi.de/mot/gearbox.html
Duane Ausherman - Transmission Repair: http://w6rec.com/bmw-motorcycle-5-6-and ... on-repair/
Anton Largiader - BMW Airhead Transmission: http://www.largiader.com/tech/airtrans/
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" onclick="window.open(this.href);return false; - It works!


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