Foton 404 hydraulic drive

[Chris D]

After 8 years my 404 let me down with a general lack of hydraulic power. I found the problem. The hydraulic pump is not turning due to the "tongue" coupling (that transfers the drive to it) having sheared or, specifically, the female slot now ceases to correctly engage the tongue on the gear pump input shaft. The coupling appears to be repairable with some careful welding and grinding of the coupling. Has anyone experienced this (failure) and how did they repair it please or where did they buy the replacement coupling from? Many thanks.

 

[jacques54]

You are not the first one that have this problem. If I remember well, the drive is too short and cause the pump or drive to round up. There is another better drive avaliable, at Affordable Tractor , if I am right. Check the depth of drive in the pump. On my tractor, the last time I had checked it was OK and I reassemble without the gasket but with a light coat of sealant.
Good luck.

 

[Chris D]

Thanks. Being a long way from Affordable Tractors, I have chosen to make another Oldham Link like the one that had failed. I'll post photos once it's all done. Good hint about removing the gasket . Interesting that many Chinese tractor makers use this drive method which is designed to accommodate misalignment of parallel shafts. A spline or a keyway is an alternative. Cheers.

 

[Bob Rooks]

Interesting that many Chinese tractor makers use this drive method which is designed to accommodate misalignment of parallel shafts. A spline or a keyway is an alternative. Cheers.

It should be noted that the Tang Drive system is used widely throughout the US and Europe, as well as China. Personally, I don't think there is enough room to install an Oldham coupling unless you fabricate a spool piece.

 

[Chris D]

The tractor (Foton 404) is going again. I had a new coupling machined locally, put a new 7005 bearing on the shaft (had to use a Dremel to slit the inner race of the old bearing for removal) and fitted new shaft seals to the pump. I will be buying a new set of bearings and a genuine spare coupling from Tommy at Affordable tractors in readiness for a future repair. Point of note for Australians on this forum is that the spares from Affordable are much cheaper than locally. The 7005 angular contact bearings are not easily available from your local bearing supplier and they are quite expensive. Two of these bearings support the gear that drives the main hydraulic pump (rear facing) and the power steering pump (front facing). Tommy will ship to Australia and has all of these spares on the shelf.

Thanks to all who offered advice.