Honda HR173 self-propelled gearbox/transmission

[OneManWentToMow]

Does anyone know the grade of oil to use in a Honda HR173 rear drive gearbox/transmission?

Also what's the recommended way to check and replace the oil?  Does it require removal of the gearbox from the machine then opening the bottom plate, or is it OK to turn the whole mower upside down and open the bottom plate while the gearbox is still in situ?  There doesn't seem to be a drain plug or fill hole.

I can't find any sign of a manual on the internet which covers the gearbox, or any YouTube videos.  Lots of info is available for the push version of the mower, but nothing for the self-propelled version.

Many thanks in advance,

Simon

[Mick]

Hi Simon, and welcome to TGMForum.  The gearbox is considered a sealed and none serviceable unit.  They usually just get replaced when they stop working properly.

I've never had one apart if being honest because you can't normally do much with them. 

[OneManWentToMow]

Thanks Mick.

I've just bought the used but very good condition mower very cheaply as a non-runner.  Now got it going after stripping and cleaning the carb.

Although the gearbox seems to work OK I'm a "replace the oil regularly" sort of bloke, especially on a machine where I don't know the history, and am always a bit sceptical about "sealed for life" mechanical units.

So I think I'll turn the mower over and cautiously remove the bottom plate to see what the oil's like, then replace it anyway with some general transmission oil.

If I'm going to do that presumably it's worth draining the engine oil and petrol beforehand, to minimise the chances of either getting into the wrong places while the mower's upside down?

Cheers,

Simon

[Swissqp]

Simon, Honda's serviceable gearboxes (not hydrostatic take 80w90 hypoid oil. Be careful with the gasket! Good luck.