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Yanmar Kanzaki KM4A

D

DreamingOn

New member
Kanzaki KM4A mated to 4JH4AE. Forward gear works fine, but frequently will not select reverse, or reverse comes in only at high revs.

Any ideas please.
 
Your Gear has a cone clutch, Delayed engagement is usually caused by the cone clutch getting glazed. It is important to run the correct gear oil in a cone clutch transmission.
Yanmar recommends:
3JH4E, 4JH4AE: • SAE Viscosity #90 or 80W90 • QuickSilver® 1 High Performance Gear Lube.

Years ago when a delayed shift would happen in transmission with a glazed cone clutch, we would replace the Gear oil with Diesel Fuel, run the engine and shift it in and out of the gear that was delayed a bunch of times, drain the diesel and fill it with the recommended oil . It worked.

These days I will tell you to pull the gear apart and replace the clutch. What you chose to do is up to you....Make sure you use the correct oil when refilling..
 
Attila said:
Attila. My KM4A gear box doesn't come out even whit excessive force !! What should I do ??
Click to expand...
The splined shaft of the gearbox is most likely rusted solid to the damper plate on the flywheel.
There are a couple of internet mentions of opening up the vent hole on the bell housing/mounting plate to access the 12 mm bolts holding the plate to the flywheel. Then the box should come off with the damper plate still rusted onto the splined shaft. I am going through this now. In the process I have snapped part of the mounting plate off the gearbox....so if anyone has a spare please let me know!!
 
Hi! Thanks for your reply . Did you have it out in a way was suggested in the internet ? What kind of engine do you have?
 
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