Robbo here in Brisbane NEED HELP !!! Gearbox

[RobboDaYobbo]

Please Help - What is going with the SLIPPING on my TwinDisc MG 340 Gear Box ??
I am about to give up. Bought an old bucket months ago... Spend every day for months.. Finally got her floating, engine started and overheating problem fixe.
then throttle went..
NOW ( see pictures ) the gear box seems to be slipping.

#1 It was running fine the other day in reverse for our 30 minute overheating test.
Could not get it in to FWD gear

#2. Now I have lost FWD & REV gear.

#3. When I tightened the nut on the end of the gear lever, it seemed to ' slip ' more. When I loosened the nut. It seemed to almost grab something and have some sort of torque behind it..

Started the motor and not going in to REV nor FWD.

#4 Gear oil was a generic top brand though. 80 - 90 W.


QUESTION.... ( apart from what the hell am I doing wrong )
a ) can wrong gear oil be a problem IF YES please recommend correct gear oil for
-- a ( Kubota motor ) twindisc MG 340 gear box.
-- b -- can too much gear oil cause a problem of slipping ??


Gear box is turning slowly in fwd & rev.... but does not spin faster as I increase the Throttle...

Who's got the answer ???

Cheers

ROBBO in Brisbane... Stuck moored up again... really want to get out on the ocean and quick...

Cheers

[Simi 60]

Wrong oil for a start me thinks, plate on side of gearbox will tell you
Our TD and most others from what I read takes 30 weight, Gibbs truck parts at Hemant has 20 litre drums for the trawler guys

[Wotname]

AFAIK, your gearbox is a rather simple mechanical box with cone clutches. I would be very surprised if your 80-90 gear oil is the right oil; I would have expected it to need something much much lighter.

Somewhere between ATF (~SAE10) through to SAE40.

I'd suggest a google search for a service manual for the box.

EDIT - cross posted with Simi but we are both on the same wavelength

[skipperpete]

Add me to the “wrong oil “ list. The brochure says 20/30.

[GordMay]

Greetings and welcome aboard the CF, Robbo.

[RobboDaYobbo]

Originally Posted by Wotname

AFAIK, your gearbox is a rather simple mechanical box with cone clutches. I would be very surprised if your 80-90 gear oil is the right oil; I would have expected it to need something much much lighter.

Somewhere between ATF (~SAE10) through to SAE40.

I'd suggest a google search for a service manual for the box.

EDIT - cross posted with Simi but we are both on the same wavelength

REPLY from ROBBO.....

THANKS guys.,.. yes I rang a gear box expert this morning on the north side of brisbane.. and he stated the same and have drained the gear oil.. and put 15 - 40 W engine oil in as instructed....

It for a little while.. grabbed quickly REVERSE gear again....
but only spinning VERY VERY slowly in FWD...

Does loosening // tightening the Nut on the side gear lever / arm, do anything ?? Should it be fully tight or a little backed off..

as I back the nut off/ loosen. The gear arm slips out a few MMs as I push it to FWD or REV gear..

I of course have also tried to move the gear lever with the nut fully tight also... seems to slip more internally when really tight..

Any other options fella than unbolting the prop shaft and taking gear box fully off ???


*** when it did grab reverse... it really grabbed it.. and stayed in gear.... but we tried fwds straight after... no FWD and lost REV motion too.. ???

would like to get out of manly harbour at least this year...

THANKS AGAIN mates.... really nice to have free help right now.. ( disability pension just started.. not happy about that.. )

cheers
Robbo

[RobboDaYobbo]

Originally Posted by skipperpete

Add me to the “wrong oil “ list. The brochure says 20/30.

is 15 - 40 W not going to work ??
or does it have to be that specific engine oil ... 20 - 30... it's back to repco for about the 100th time if that's the case.

Originally Posted by Wotname

AFAIK, your gearbox is a rather simple mechanical box with cone clutches. I would be very surprised if your 80-90 gear oil is the right oil; I would have expected it to need something much much lighter.

Somewhere between ATF (~SAE10) through to SAE40.

I'd suggest a google search for a service manual for the box.

EDIT - cross posted with Simi but we are both on the same wavelength

REPLY from ROBBO.....

THANKS guys.,.. yes I rang a gear box expert this morning on the north side of brisbane.. and he stated the same and have drained the gear oil.. and put 15 - 40 W engine oil in as instructed....

It for a little while.. grabbed quickly REVERSE gear again....
but only spinning VERY VERY slowly in FWD...

Does loosening // tightening the Nut on the side gear lever / arm, do anything ?? Should it be fully tight or a little backed off..

as I back the nut off/ loosen. The gear arm slips out a few MMs as I push it to FWD or REV gear..

I of course have also tried to move the gear lever with the nut fully tight also... seems to slip more internally when really tight..

Any other options fella than unbolting the prop shaft and taking gear box fully off ???


*** when it did grab reverse... it really grabbed it.. and stayed in gear.... but we tried fwds straight after... no FWD and lost REV motion too.. ???

would like to get out of manly harbour at least this year...

THANKS AGAIN mates.... really nice to have free help right now.. ( disability pension just started.. not happy about that.. )

cheers
Robbo

[RobboDaYobbo]

Originally Posted by Simi 60

Wrong oil for a start me thinks, plate on side of gearbox will tell you
Our TD and most others from what I read takes 30 weight, Gibbs truck parts at Hemant has 20 litre drums for the trawler guys

Originally Posted by Wotname

AFAIK, your gearbox is a rather simple mechanical box with cone clutches. I would be very surprised if your 80-90 gear oil is the right oil; I would have expected it to need something much much lighter.

Somewhere between ATF (~SAE10) through to SAE40.

I'd suggest a google search for a service manual for the box.

EDIT - cross posted with Simi but we are both on the same wavelength

REPLY from ROBBO.....

THANKS guys.,.. yes I rang a gear box expert this morning on the north side of brisbane.. and he stated the same and have drained the gear oil.. and put 15 - 40 W engine oil in as instructed....

It for a little while.. grabbed quickly REVERSE gear again....
but only spinning VERY VERY slowly in FWD...

Does loosening // tightening the Nut on the side gear lever / arm, do anything ?? Should it be fully tight or a little backed off..

as I back the nut off/ loosen. The gear arm slips out a few MMs as I push it to FWD or REV gear..

I of course have also tried to move the gear lever with the nut fully tight also... seems to slip more internally when really tight..

Any other options fella than unbolting the prop shaft and taking gear box fully off ???


*** when it did grab reverse... it really grabbed it.. and stayed in gear.... but we tried fwds straight after... no FWD and lost REV motion too.. ???

would like to get out of manly harbour at least this year...

THANKS AGAIN mates.... really nice to have free help right now.. ( disability pension just started.. not happy about that.. )

cheers
Robbo

[Simi 60]

Originally Posted by RobboDaYobbo

REPLY from ROBBO.....

THANKS guys.,.. yes I rang a gear box expert this morning on the north side of brisbane.. and he stated the same and have drained the gear oil.. and put 15 - 40 W engine oil in as instructed....

Doubt you got that info from TD

When they did work on ours last year they near had a stroke when they saw the Castrol RX 15/40 in the ER but behind that drum was the 30 mono and they calmed back down.

[skipperpete]

Originally Posted by Simi 60

Doubt you got that info from TD



When they did work on ours last year they near had a stroke when they saw the Castrol RX 15/40 in the ER but behind that drum was the 30 mono and they calmed back down.

But you have a real US twindisc, the op has an italian gearbox that twindisc rebranded. Very small but reasonably good little gearbox.

[Compass790]

I'd bet lunch on it that changing from 15w-40 to mono 30 wont fix his problem though.
Can see how EP 90 would be a problem.

[skipperpete]

Hey Robbo, that gearbox is probably a Technodrive TMC 40 and their user guide says ATF, not 15/30 like the Twindisc user guide says so maybe drop out the oil again and try ATF, it only takes 200ml. It might make a difference but I don’t think you’ll get Compass790’s lunch.

[Compass790]

Originally Posted by skipperpete

Hey Robbo, that gearbox is probably a Technodrive TMC 40 and their user guide says ATF, not 15/30 like the Twindisc user guide says so maybe drop out the oil again and try ATF, it only takes 200ml. It might make a difference but I don’t think you’ll get Compass790’s lunch.

No chance!
I was only wagering on the difference btwn 15w-40 & mono 30 not ATF & 15w-40.
ATF may solve his problems, be interesting to see.