gearbox technodrive TM345A rotate in neutral

Hello everybody

I have baught the use boat (ARVOR190) of my dream with inboard engine VW SDI 50 and the gearbox is a Technodrive TM345A .I have a very strange issue in neutral the propeller and the shaft at the output of the gearbox are spinning very very slowly .The engine has ran 60 hours in 5 years .I haven't put a piece of wood in the propeller to see if there is force on it

Have you an idea about this trouble ?

Thanks in advance for your answer

 

This one? (spec sheet http://www.technodrive.it/italy/invertitore-marino/pdf/TM_345A.pdf )

Looks like it has hydraulically operated clutches... perhaps one of them is dragging very slightly. How fast is the shaft spinning (very slowly = 1 rpm, 5 rpm, 60 rpm,...?), is it spinning in forward or reverse, and is it transmitting significant torque? (I wouldn't advise sticking wood in the prop, but holding a piece of wood against the shaft inside the boat might give you an idea of whether or not it's easily stopped- be careful!!!)

 

thanks for your answer

Your spec sheet is the good one .How does it work an hydraulically operated clutches ?
It is spinning slowly in neutral position .I will hold a piece of wood against the shaft to see if there is torque .Thanks for the advice

 

This is normal behavior caused by whirling of the oil in the gearbox, especially at low temperatures or when the oil cooling option is installed.

Make sure the oil level is correct and the color is red. Technomarine gearboxes use ATF, not engine oil.

 

I am not sure that all Technomarine gearbox use ATF oil , I have found on the net the user manual of my gearbox TM345A and the oil is Api cd sae 20w40
http://www.dieselpowersweden.se/images/paragraph/28493.pdf
I have done the test to evaluate the torque on the propeler shaft ,I could stop the shaft with my hand .I agree with you the oil is probably to thick or cold

 

If the manual states that, I was wrong. My 2007 manual covers several types from small to large, all using ATF, but does not include the TM345A.