Technodrive TMC40M clutch slipping?

[oldmanofthehills]

I think the most important thing with these boxes is to change the oil every year, and make sure it stays clean.

I think the most important thing is to use a more reliable clutch system, such as used for many many years by numerous other marine gearbox manufacturers

 

[bluerm166]

Perhaps someone who has experienced a failed TMC40 could do a questionnaire of first owners so that we can get an impression of the falure rate .
e.g. failed at x nautical miles ,y years after I bought it new,comment e.g.replaced under warranty or still running.
My TMC 40 ws running happily when we lifted out but I would like to see and contribute to a similar questionaire on Raymarine tiller pilots ,whose failure rate must be a great deal higher.

 

[Boater Sam]

I would pension it off and replace with a PRM95 which will be infinitely reliable. Almost a straight swap, just a slight drop height difference.

 

[fishermantwo]

Interesting.

I can't find any reference to the grade of ATF in the Operating Manual that came with mine.

I have a Service Manual for what I assume is the earlier marine unit (TMC 40) and that specifies SAE 20 -W40. The Service Manual for the TMC 40M (my gearbox) just says ATF. I have looked on line at the manual, shown at present on the Beta website, for the TMC 40P and that also says - ATF.

I am not sure what the differences are between the 40 the 40M and the 40P series gearboxes. Anyone know?

.

The gear ratios are different.
From my notes, The ATF should meet Allison C-3 or Caterpillar TO-2 specifications or Dexron 2 if available. Dexron 3 and above have too much in the way of additives and may foam. I can not find the manual now but I did take a photo of the adjustment procedure.

 

[Tranona]

I would pension it off and replace with a PRM95 which will be infinitely reliable. Almost a straight swap, just a slight drop height difference.

See post#9. not quite so simple as the PRM is also a bit longer, but doable. However if the TMC is a 2.65:1 a different propeller (or repitching) may be needed, particularly if it is a feathering propeller with a different pitch forward and reverse. The TMC is 2.65 in forward and 2:1 reverse and the PRM is 2.5:1 both ways.

 

[fishermantwo]

Talk about not reading my own posts! The ATF specifications are in the bottom part of the first photo from the manual above. Basically what the manufacturer is saying is modern ATF"s meant for the new generation of cars are too good for a gearbox that needs some friction.

 

[PaulGS]

The gear ratios are different.
From my notes, The ATF should meet Allison C-3 or Caterpillar TO-2 specifications or Dexron 2 if available. Dexron 3 and above have too much in the way of additives and may foam. I can not find the manual now but I did take a photo of the adjustment procedure.View attachment 171740View attachment 171742

Thank you for posting this. This is the procedure I intend to carry out. I'll likely change the oil too (though it looks like honey and I very much doubt that it's an issue in this instance - it's "ATF".

 

[fishermantwo]

ATF is always red. Honey coloured makes it a hydraulic oil.