E8000 clutch failure?

[Wellwicked51]

Hi all, e8000 clutch failure

 

[Greg Watts]

Hi all, e8000 clutch failure

Welcome to the forum, @Wellwicked51. You'll need to give us a bit more to go on, but "clutch failure" on the E8000 is a known pattern so let me give you what's useful in the meantime.

The E8000 uses a one-way clutch (sprag-type bearing) to disengage the motor from the drivetrain above the assist speed limit, and to allow freewheeling when you're not pedalling. When this clutch starts to fail, the classic symptoms are: motor continues to spin while drive to the crank drops out or becomes intermittent, a sudden loss of assist that comes and goes, or a grinding/spinning sensation when you'd expect engagement. Our community knowledge backs this up, noting that

"belt and sprag clutch (freewheel) failures are the typical symptoms" of this kind of motor issue.

The other presentation worth ruling out first is actually the derailleur clutch rather than the motor clutch.

Forum members have seen the E8000 throw an E010 fault mid-ride with no warning, and the motor powering off and on under load, regardless of assist mode, at higher cadence and torque

is a well-documented symptom before things go fully south. If it is the motor clutch internally: Shimano won't sell you spares, so you're looking at either a full motor replacement or a third-party repair specialist.

Not all dealers are equal here, a Shimano Service Centre specifically managed to source a replacement motor at roughly a third of standard price on one out-of-warranty case, so it's worth ringing around rather than just accepting the first quote.

Third-party repairers do exist who will do bearing and clutch replacement as a service if you'd rather not buy new.

Tell us what symptoms you're actually seeing, any error codes showing on the display, and roughly how many kilometres are on the motor. That'll help nail down whether you're looking at the clutch, the torque sensor, or something else entirely.

 

[Wellwicked51]

Hi I was riding and then the pedals started feeling sort of soft then I heard and felt a crunch and the cranks now spin freely forwards and backwards and do not engage

 

[Greg Watts]

Hi I was riding and then the pedals started feeling sort of soft then I heard and felt a crunch and the cranks now spin freely forwards and backwards and do not engage

That crunch and the cranks spinning freely in both directions is pretty conclusive, @Wellwicked51. That's the sprag clutch gone, not just wearing out but properly failed. When it's healthy, the one-way clutch should lock in the forward direction and freewheel in reverse. If you're getting zero engagement either way, the sprag elements have either collapsed or sheared, which is exactly what that crunch would have been.

The "soft" feeling beforehand is textbook too. The clutch was slipping before it let go completely, meaning the sprags were losing their bite under load before the final catastrophic moment.

At this point there's nothing to troubleshoot or adjust externally. The motor needs to come apart. Your options are: a Shimano Service Centre for a motor replacement (ring several, as pricing varies wildly and some can source units at a significant discount on out-of-warranty cases), or a third-party specialist who'll open the motor and replace the clutch assembly and bearings directly. The latter is usually cheaper but availability depends on where you are in the country.

Before you start ringing around, it's worth noting the mileage on the motor and whether it's still under any warranty. How old is the bike, and roughly how many kilometres on it?