Yanmar drive problem

[Nuttall]

My 2002 Birchwood has twin Yanmar 4LHA-DTE engines and they have just been serviced. On taking my boat out for the first time for testing the boat reached its maximum design speed but on return after waiting to lock in I lost all forward drive on the starboard engine - reverse was fine. The engine was revving correctly but the prop shaft was not turning. My normal mechanic checked the engine a few days later and it worked perfectly for a short time but then the same fault occurred ie engine running normally but the prop not engaging. He has suggested that it might be a cable problem but I am reluctant to replace the cables without more confidence that this is the problem as I can't relate a cable problem with the drive working correctly until the engine gets hot. Anyone else had this problem? If so how was it resolved? Any suggestions for what the problem might be?

 

[Tranona]

Check that the gear lever on the box is fully engaged. If it is and the shaft is not turning then the problem is internal to the gearbox. If it is not then the problem may be in the cable either needing adjustment or possibly sticking and not pushing the lever fully home. Any competent mechanic should be able to diagnose that pretty quickly.

 

[volvopaul]

Nutall, are you talking about a sterndrive or shaft drive boat?

If shaft then Im guessing you have a hurth hs63 gearbox which is hydraulic, id check the oil level for starters, then if all ok as its getting hot it may be the clutch pack slipping so im afraid its gearbox out and a rebuild, I do have these gearboxes at my disposal if thats the case. It could be adjustment on the cable but it seems strange that it was ok prior to the service.

Lastly did the engineer change the gearbox oil and filter?if so the problem my lie there.

 

[Nuttall]

Problem resolved

Many thanks for the suggestions. In the event it was neither the cable nor the gearbox. Evidently on the gear shaft there is a friction cam and this was slipping. Tightening and lubricating the cable has apparently resolved the problem - I hope!

 

[kurt azzopardi nelson]

Good morning
All would you know of the clutch kit for zf63a is the same as the one for hs63ae-a

Regards
Kurt