Tanaka THT-2000 hedge trimmer blades shudder at full speed.
Background
Water had got into the gear-case over the winter, causing the drive pinion and bearings to rust and seize solid.
I replaced the clutch drum & pinion assembly and both bearings, and cleaned up the cutters, the oscillating gear and the guide plate. (The clutch drum & pinion assembly and the bearings were driven into position using heat/cold method.)
The bearings & gears turn OK and the blades move easily so I can't feel any binding; and at anything up to about two-thirds revs its all working perfectly with little or no vibration . . .
Problem
. . . But at full throttle the blades shudder every few seconds, shaking the whole machine. It's hard to see exactly what's happening due to the speed-blur.
What I've tried
I thought it might be clutch slipping and re-engaging due to the new clutch drum not bedding in with the existing centrifugal [metal] clutch. So I emery-papered the drum and clutch but it hasn't helped.
I experimented with the cutter fixing bolts, slightly tightening then loosening either side of the required half turn out but that didn't work either.
Help please - I'm at a loss to explain or fix this problem, has anyone come across this phenomenon before on this or other makes?
Tanaka THT2000 components.png
Background
Water had got into the gear-case over the winter, causing the drive pinion and bearings to rust and seize solid.
I replaced the clutch drum & pinion assembly and both bearings, and cleaned up the cutters, the oscillating gear and the guide plate. (The clutch drum & pinion assembly and the bearings were driven into position using heat/cold method.)
The bearings & gears turn OK and the blades move easily so I can't feel any binding; and at anything up to about two-thirds revs its all working perfectly with little or no vibration . . .
Problem
. . . But at full throttle the blades shudder every few seconds, shaking the whole machine. It's hard to see exactly what's happening due to the speed-blur.
What I've tried
I thought it might be clutch slipping and re-engaging due to the new clutch drum not bedding in with the existing centrifugal [metal] clutch. So I emery-papered the drum and clutch but it hasn't helped.
I experimented with the cutter fixing bolts, slightly tightening then loosening either side of the required half turn out but that didn't work either.
Help please - I'm at a loss to explain or fix this problem, has anyone come across this phenomenon before on this or other makes?
Tanaka THT2000 components.png
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