My 26 year old HR-214 just started having a similar problem. It works great in LOW speed, but if I shift to HIGH speed and engage the clutch it jerks forward slightly and makes a knocking sound from the transmission gear case. Like yours, drive shaft from the engine keeps rotating steadily.

Is yours having trouble in LOW, HIGH, or both?

You have a great more on your hands - invest in the manual. I bought the Honda shop manual years ago and have found it very useful. While it is not an especially well designed or well written manual (as with many Asian manuals), it is of great value if you dig into the engine, blade clutch or transmission.

A few things I have checked:

1) No obvious transmission case cracks or oil leaks.
2) Knocking is definitely coming from the transmission - I can feel it knock if I remove the plastic cover between the back of the engine and the trans and touch the housing.
3) Transmission shift cable runs free.

Hi JP.

Mine does it in both speeds but it's more noticeable in high. There are two clutches in the gearbox--one for high-low and one for start-stop (I called that the "traction clutch" in my original post). So I am thinking the problem lies with the start-stop clutch. The cables and springs seem fine but I might be missing something.

I'm thinking that getting to the bottom of this is going to require pulling the gearbox and opening it up.

I keep hoping to find the manual on line somewhere.

Alan

I discovered the trouble and HIGH_SPEED works again (on the work bench).

The trouble with my HR214 transmission was the cam that pushes on end of the high/low shifting shaft had partially worn away. The high/low shifting shaft protrudes from the transmission about 3/8" to 1/2". When the HIGH/LOW Lever on the mower handle is pushed to the HIGH position, the control cable pulls on crank on the transmission, turning a shaft that rotates a cam, pushing the high/low shifting shaft into the transmission until it is about flush.

It is not obvious, but the high/low shifting shaft spins slowly when the mower is operating. Over time and years of use, the rotating shaft end wore away the lobe on the end of the cam; about 3/32" to 1/8" is worn down. A new part is available from Honda for about $13 as P/N 22532-VA3-801, but no lawn equipment dealer in my city had one in stock. I weld, so I built up the cam lobe with some Stellite 6 hard-facing alloy and my TIG torch. The repaired part should outlast a new one.

Everything got reassembled on Friday and HIGH_SPEED again works like the mower was new.

If you find you're having trouble with the transmission either making a knocking sound when shifted to HIGH or no movement at all in HIGH, take the motor to transmission drive cover off to expose the transmission. Wash off the transmission or blow it clean with compressed air.

Cycle the high/low shift lever on the mower handle to locate the high/low shift lever on the transmission. Look at the opposite end of the shaft from the arm where the shift cable attaches to find the gear shift cam; the cam is about 1" long. Look for a small notch in the side of the cam. Just beyond the notch is the surface that pushes on the end of the shifting shaft. The cam pushes on the end of a 1/2" long shaft, pushing it in to select HIGH and letting it spring out for LOW. Use an inspection mirror to see the point where the cam rides against the end of the shaft. If the end of the cam has a flat spot worn at the point of contact, you have found the problem.

Only a small amount of metal need be worn away (1/16" - 1/8") for the transmission HIGH gear not to engage fully. As mentioned in the previous post, the replacement cam is Honda part P/N 22532-VA3-801 and sells for about $13.

It's a pity there is no way to post some of the photos I took so readers could see exactly what to look for.

Hey jpcallan,

I'm restoring a hr214 on my blog...can you send me the pics so I can post about the repair? I'd be happy to give you credit of course.

JTM

Here is a link that might be useful: Honda hr214 Blog