Not familiar with the KM. I have a ZF63a. Bit of an industry standard for 4cyl and smaller 6s. I'd go the ZF25A on name and reputation. Bullet proof boxes. Mine is at 15,000hr now.
Hi there!
Would anyone here know which of the two gearbox offered by Yanmar is the better choice?
The Yanmar 4jh3-dte-125-hp has a choice of two transmissions, the KM4A-2 and the ZF 25A.
I don't know enough to make that call.
Your thoughts are appreciated.
I’d assume these arnt cheap
Who ever is selling it to you should know the pros and cons of each
If not go buy elsewhere
Hi Steve ... yes, but things don't work like that unfortunately. Agents are there to serve themselves not the customer. And they probably don't know, don't care, or would rather sell me whatever suits them.
It is ZF versus Kanzaki.
KM4A-2
Marine gears developed for the sail boat.
Specifications
Clutch type Mechanical servo cone clutch (Angle drive) Input torque (N・m) 241 (@3,200rpm) Reduction ratio (Forward) 1.47:1 2.14:1 2.63:1 Reduction ratio (Reverce) 1.47:1 2.14:1 2.63:1 Input rotation Anticlockwise Output rotation (from the stern) Clockwise or Anticlockwise (Forward)
Clockwise or Anticlockwise (Reverce)Oil(L) SAE #20/#30 (Single Grade) Oil capacity(L) 3 Weight (Dry) (kg) 28.5 Standard flange SAE #4
(Option: Borg Warner flange will be available for any other SAE flange)
And the ZF
https://www.performancediesel.com/wp...oads/ZF25A.pdf
Listen to Smithy!
What could go wrong.......................
Yep, that is the idea of asking others for their opinion.
ZF used to be top of the choice but has long fallen back from their former reputation. I don't remember much of the details but it has to do with who owns what, no different from all the other reputable brands that ended up being built in India, China or some other place. But since I don't know the details, I have asked here and elsewhere. ZF from 20-30 years ago are not the ZF of today. Unfortunately.
This is what I was told so far.
Here, one in favour of ZF.
Lancing marine, a transmission rebuild place of 30 years in the UK, says that they have ZF in the bargain list and the KM is only supplied by Yanmar at atrocious prices since they own it. Well thank you but that does not help me ... (?)
Witchard Marine, says use ZF
The Yanmar retailer says use KM.
But there is more to the story. The KM gearbox and the ZF gearbox are both mechanical and rather clunky.
KM has a hidraulic option called KMH4A and that is obviously the better choice but not because of the brand.
Anyway, still making more enquiries.
This is the Hidraulic version of the Kanzaki
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