What is that this drive prepare noise?

Has you had your drive shaft checked underneath the recall?

My pal purchased this bike and on the time, was informed it had a 28,000 mile service and all checked out good. He took it to a BMW dealership that informed him they “we drained the oil within the differential and checked it. Nothing was mistaken with it. Don’t analyze the rear on a stand.” I’ve had two R1200GS’s and neither made any of these crunching noises. We had requested ChatGPT for options, listed below are the ChatGPT directions:

What “all gears” suggests
• If the similar catching/metallic engagement sound occurs in each gearit’s much less doubtless to be:
• A single worn gear canine or shift fork (these normally present up in only one gear).

As a substitute, it factors extra towards a part widespread to all gears:
1. Driveshaft
• Failing U-joint ? can bind and launch in any gear, similar noise no matter choice.
• Splines (transmission ? shaft, or shaft ? ultimate drive) worn or dry ? chatter/skip earlier than re-engaging.
2. Closing Drive (bevel gear/pinion)
• Worn pinion gear tooth or unhealthy bearing ? may give a catching/grinding sensation each time torque is utilized, impartial of substances.
• Noise will monitor street pace somewhat than engine RPM.
3. Enter/Output shaft (inside gearbox)
• If the output shaft bearings are failing, it might permit lash/play in all gears, inflicting that metallic catch earlier than drive takes up.
• However this normally additionally provides additional vibration via the pegs and robust steel in engine oil.

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How you can Differentiate (Secure Assessments)
1. Coast Check
• Trip in gear ? pull clutch ? coast in impartial with engine at idle.
• If noise continues with street pace ? driveshaft or ultimate drive.
• If noise disappears with clutch in ? gearbox shaft.
2. Wheel Spin Check (engine off, bike in impartial, heart stand)
• Rotate wheel by hand.
• Really feel for notchy resistance ? ultimate drive bearing/pinion.
• If clean ? extra doubtless driveshaft.
3. Oil Verify
• Drain ultimate drive oil (180 ml, simple). Search for metallic paste or chips.
• Drain engine oil (shared with transmission). Verify for flakes.
• Discovering steel in a single or the opposite narrows it down quick.

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Security Word
• If it’s in all gears and appears like steel catchingI’d be very cautious about driving.
• A failing U-joint can let go all of a sudden ? rear wheel locks.
• A failing pinion bearing can seize the ultimate drive.
• Each are severe dangers at pace.

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Primarily based in your description (occurs in all gears, feels like steel catching then participating), my prime suspects are:
1. Driveshaft U-joint beginning to fail
2. Closing drive pinion/crown gear challenge