Common faults/improvement on Airhead GS's

Kenny

Kenny

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OK...a recent posting about replacing exhaust valves at a certain mileage/age got me thinking about putting up this post as a sticky so we ( and future ) owners can refer to it when applicable. We read lots (mostly American - and OTT in many cases) about the common problems on these bikes but in this forum have a large amount of the UK airhead/GS owners, so lets pool our knowledge collectively :)

So, for example, could forum members ( and no theories/web links please, just facts that have happened to you ) who have actually had paralever shafts fail...where did you get the repair/cost/mileage/who etc etc

Same for valves or head re-builds; diode boards; gearboxes; alternator/rotors; wiring harnesses etc etc..you get the drift:thumb2

I put this up as I've never had a gearbox fail or even a rotor, yet many have !!

This will be an excellant record of UK gs's for members new and old to refer to in the future:thumb2
 
Kenny said:

This will be an excellant record of UK gs's for members new and old to refer to in the future:thumb2
Click to expand...

So is it only if somethings failed and you've sorted it you comment or is it acceptable to post replacement parts such as Thunderchild Diode boards which you have fitted in anticipation of a failure? :nenau
 
I think it would be excellant if people posted their replacement mods for the failed OE parts....and I can't think of many better to start this topic :thumb2

This is going to be a sticky so genuine replies only and not just recommending mates garages/web links etc
 
Paralever driveshaft

Just started to fail at 42,000 miles

replaced by upgraded one by henderson engineering in the states.
Replacable joint with grease nipples and upgraded silicone damper insert.

Cost around £240 + p&p:thumb2
 
1990 100GS

Rear shock failed at 45000 miles replaced with Hagon and working well.
Driveshaft failed at rear UJ at around 65000 miles. Replaced with secondhand original(thanks Lurcher and Jaythro) and working well.
 
1993 100GS PD

Gearbox needed rebuild at around 28000 ( on the English speedo, so may have done more on the previous German one ). New bearings fitted, shaft checked -all done by Gary at BAMW.
Now runs fine.

Hi Output Voltage Regulator -just in case !
 
Diode board sarted playing up/not chargeing when engine got hot
Got a Thunderchild new board fitted with higher temp spec diodes also solid mounting screws and a uprated regulator 14.5v as against 13,6 BMW standard 90 $ deliverd from San Diego CA - top piece of kit fitted these to 3 bikes now as a re-pacement/upgrade no more switching lights off etc. when in town trafic or greenlaneing - always has starting power in the battery :thumb2
 
R100GS Valeo starter motor dropped magnet at 26000 miles replaced motorworks posted out to me in France 48hr delivery. This was faster than I could source localy. Rear hub bearings collapsed at 35,000 replaced hub with second hand from Motobins. Cracked coil not picked up and replaced with later pattern. Motorworks.

2nd R100GS. Overcharged gel battery melting it to the frame. Voltage regulator failed. 14 miles from Dover on my way down to South France
 
Well so far its gearbox, starter, driveshaft , diode ,valve guidesand shocks that seem to be the most usual things
:robIve had gearbox(Repaired by myself though never delved into one before. Still sweet after 3 years)
starter.( again self repaired)
Valves. stripped by me and fitted with K-Line valve guiude inserts. cheap quick and inexpensive.
shock( Ohlins) rebuilt by them
Complete engine rebuild after catastrophic failure of the oil preassure due to a faulty O ring. rebuild by Scrimminger, cant speak highly enough.
The $2000 dollar O ring is well worth reading on Sorebums site.
The great strength and appeal of these bikes is that they can be stripped
and repaired again and again even by numpties like me( with care and
advice)which is why we stick with them I suppose.
 
1988 100gs

shaft snapped in half by u j knuckle at 40,000 ish miles :( replaced with second hand shaft cant remember where from it was a long time ago.

ive had 5 or 6 GS's an 3 have had to have the starters repaired , usually hand over £80/100 for a rebuilt starter from auto electrical place near colchester.

I had to have a gearbox rebuilt at motoworks BUT only because it had no oil:blast:blast:blast £250 bill......... that will teach me.

but their still the best bikes out there:thumb
 
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Starter replaced at 30,000 miles.
Driveshaft removed - inspected - all OK - greased and refitted at 44,000 miles.
OE Rear Shock exploded at 36,000 miles - replaced with Ohlins from Motorworks @ about £450. Put in progressive fork springs at the same time about £90 - makes a worthwhile difference.

Previous GS re-built (22,000 miles) engine after incorrectly shimmed Oil Filter
 
Hi

1989 R100GS. Valeo starter lost its magnets 6 years ago. Rebuilt starter developed a short in solenoid 1 year ago.

Valeo replaced by Nippondenso.


Steve
 
My previous R100GS - Little Gringo

Drive shaft started failing at 46k miles, replaced with new at some dodgy garage in Neasden before I knew better. Cost -- think was around £380 :eek:

Gearbox output shaft seal started leaking at 50k odd miles, stripped the gearbox in a basement and did the repairs myself - £170

Some info from way back then :augie

maverick said:
I have promised to give you guys the bearing numbers which was used and unfortunenatly misplaced them at home. Will go on search this weekend and post the details. This is all photo's that came out and wish I had taken more when stripping and reassembling the gearbox cover etc.
I used very simple tools like my camping stove to reheat the gearbox cover in order to pull it off and also the casing when replacing the shafts.
The output, layshaft and input shaft with the 1st gear selector should be dropped back in the casing the same time unlike the instructions in the haynes manual. The selector springs is easily replaced and all you need is a decent circlip plier.

Things I have replaced:
All the bearings
All the gearbox seals
All the selector springs
New gasket
New driveshaft bolts

Tools required:
Bearing puller/pullers
Flange removal plate
Thin walled socket to undo and redo the swingarm
10mm ringspanner for the driveshaft bolts
Heat gun or blow torch to heat the gearbox up
Various size sockets, spanners to undo and redo bolts
Torque wrench


All these bearings is manufactured by FAG but would think that SKF or any other manufacturer with the same type bearings should be sufficient.

Output Shaft
Flange side: 6304RSR
Housing side: 6403.C3

Layshaft: 2 X 6304.C3

Input Shaft:6304.C3

The thrust bearing and inner race do not have numbers on anymore. But it is a special bearing and might be worth while to pay the tenner and get the right part.

The output seal was replaced with the original as the input shaft seal. I believe you could probably use Viton oil seals which should do the trick fine and can stand serious heat and costs hardly anything. Some items personally prefer to stick to the original and oil seals is one of those things.

Something else forgot to mention is that I went on the assumption because the original shafts and new gasket was used again it should be very close to what it used to be. Box is better than what it was and did not expierence any lockups or false neutrals. If you do replace items like the layshaft would recommend measuring and shimming the box as described in the manuals.
Did measure mine and they seemed to be in limits.
Click to expand...

Front fork seals replaced also around 50k miles - cost was minimal but couple of hours work.

Rear bevel drive seal went also between 50k and 55k miles, had that replaced by Bracken at £70 me supplying the spares and bevel drive.

-------------------------------------------------------------------------------

Current R100GS standing in my garage

43000 miles - shaft failure - £280 from motoworks for reconditioned unit.

43500 miles - Right hand side front cam follower started cracking - they are £25 each and worth while replacing all four while you at it :mmmm

43 700 miles - gear lever tore off hanging on a small piece of metal. Think it was just a bad welding and now sorted properly by "The Chad" :D
 
g/s wiring loom, where it goes up steering head is too short and one or more wires can break internally and is a pain in the arse when it happens :(
 
Roger Chatterton said:
1993 100GS PD

Gearbox needed rebuild at around 28000 ( on the English speedo, so may have done more on the previous German one ). New bearings fitted, shaft checked -all done by Gary at BAMW.
Now runs fine.

Hi Output Voltage Regulator -just in case !
Click to expand...

do you guys(ukgs'er)rebuild gearboxes without the circlip modification? they don't seem to last very long without it.
my gearbox was rebuild , and the circlip added, at 90 000 k's now 270 000 still the on that same rebuild.
around the same time I installed a rebuild bosch starter still good.I don't think I would buy a valeo ever again , have they improved?
 
I think all the springs and circlips were replaced. Apparently the circlip/spring that I think you are refering to used to wear against a bearing or shaft in the gearbox, and hence, eventually break. I think this fault has been around for long enough now to be known, and normally fixed in any 'box rebuild. A stronger spring is normally fitted.
Valeos have been improved, I think I read this on here somewhere, but can't speak from any personal knowledge. Think they use real glue now.
 
here we go : output shaft seal on gearbox went at approx 25,000miles resulting in new (recon) box from sherlocks. this lasted about 2,000 miles so they replaced the seal which leaked straight away. had gearbox rebuilt at 55,000 and was told sherlocks had put wrong seal in the wrong way round ! diode board went at 10,000, replaced with thunderchild - brilliant. shaft lasted for about 65,000 hard miles (mainly fully loaded) and showed wear so replaced with another bmw one. alternator rotor replaced twice and stator once before 30,000. carb o-rings etc replaced regularly. original shock replaced with ohlins (original was ok) which lasted 30,000 miles before being replaced. rear subframe and mounting points regularly welded on africa trip whilst fully loaded. never changed wheel or bevel box bearings. head and swingarm bearings changed after 60,000. battery replaced with hawker gel (great) at 25,000. showing signs of age at 80,000. exhaust valves replaced at 60,000 (just in case) intake at 75,000. twin plugged at 60,000. been a bit of a pig since. big end bearings and rings at 75,000. collector box rotted after 20,000. main crankshaft seal went at 45,000, think its gone again at 80,000. cam chain is rattly so needs replacing at 80,000. starter lost a magnet around 50,000, going again at 80,000. will replace with a bosch one from motoworks. most parts are obtained from these guys as they are really good. even when abroad. replaced the black box with second hand police spec one at 20,000. this seems to help keep battery charge when in traffic or out trail riding. also replaced the cdi unit when i got a kickstart gearbox as you need the correct one to ease starting. acerbis handguards (with the ally in) have saved leavers, hands and bars after several big offs. touratec panniers brilliant, rack rubbish, constant welding on trip. i think thats it. oh almost forgot. cylinder retaining studs had threaded inserts in the crankcase on three of them at 55,000 and one of those was done again at 75,000.
 
GS 1000 Failures

Despite what people say, theses bike are not super reliable, but I enjoyed mine whilst i owned it.

1995 GS PD Classic
15,000 Km Speedo
60,000 KM Output shaft bearing & rear seal Gear Box
65,000 Km Rear Shock & fork springs
70,000 charging rotar
70,000 Head gaskets
70,000 Carb rebuilt & Fuel Tap rebuild
70,000 Para Lever bearings
75,000 DRive shaft Rebuilt $A 250
80,000km Replace Heated grips
100,000 Rechrome forks (worn out)
110,000 Outshaft shaft bearing gear box
120,000 Head & Base gaskets Gasket
Plus lots of general wear items head stock bearings, wheel bearings fork seals

124,000 KM sold big mistake I miss it lots
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
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