Yanmar 3gm30 Gearbox

[irawnsley]

Not sure at this stage what the model is but have a problem with slipping in forward and reverse. Looking to strip and repair ourselves, anyone tackled this before? manuals/diagrams? pitfalls? are spares available if so from where? All help much appreciated.

 

[beneteau_305_553]

Unlikely I think to be the gearbox. What are the exact symptoms?

 

[VicS]

A workshop manual vital I would say. I recon box if available might be the easiest option.
I have done several car boxes over the years. A couple need no special gear, another need access to a press (which I had at the time) another required professional help to change a bearing. One I could not get any of the bits I wanted so was replaced with a cheap exchange one in the end.

 

[lw395]

Not sure if CD Rom manuals are available on ebay?
The full workshop manual was about 40 quid when I bought one, well worth it. (From Marine Power Burseldon) (10yrs ago)
However, there may be plenty of used boxes around, as more people tend to wear out the engines?
Probably just have to phone around the dealers such as Marine Power Burseldon, the place at Penton Hook etc etc.
Do these 'boxes come with diffferent ratios? best to check you replace with same.

 

[Tranona]

These gearboxes are very reliable, so don't strip it down unles you have exhausted all other possibilities.

First thing to check is the selection cable to make sure the gears are being fully engaged. Also check that the clamp on the half coupling on the shaft is tight and it is not the shaft slipping.

Agree the official workshop manual is essential if you do work on the unit, but would search out a secondhand one first. There are 3 different ratios, clearly marked on the ID plate. I suspect (if it is in your Tradewind) it will be 3.2:1. The others are 2.2 and 2.6. Reverse is the same on all at 3.06

 

[Honey]

You can download a manual from http://www.motoren.ath.cx/

 

[awol]

If it is similar to the 2GM20 box, it is simplicity itself. Only quirk I found was left-hand thread on inner end of output shaft.

However, before you go that route, do check the cable linkages and what oil has been used in it.