Think the Drive is Slipping

[rossl]

Hi All,

We have a problem on our 1996 Super Sport Nautique with GT40 EFI V Drive.

At the weekend with 750lbs ballest and 4 people onboard pulling a wakeboarder the engine revs would go up for a split second under hard acceleration, it was fine if we pulled the boarder up at normal speed.

I am going to change the ATF in the velvet drive to see if that make a differnece as im not sure when it was last changed, the fluid in there was just above the lower indent on the dip stick and the normal red color (not milky).

Would old oil make the drive slip? Do i need to fill it to the second indent on the dip stick?

Cheers
Rossl

[Rick]

RE: Think the Drive is Slipping

Low oil would make it slip, old oil shouldn't unless there is something that has caused it to clog the valve. Make sure you also check the V-drive. It may be low as well.

[rossl]

RE: Think the Drive is Slipping

Whats classed as low, if it was on the first indent on the dip stick is that low enough to make it slip?

Cheers
Rossl

[78LS2]

RE: Think the Drive is Slipping

not really, especially if it was just running and the cooling lines were fully primed. Won't hurt to add some, but the low line won't cause it to slip.

[richard]

RE: Think the Drive is Slipping

Vdrive wouln't cause slip since inside composite only gears.

[rossl]

RE: Think the Drive is Slipping

Hi All,

I changed the tranny oil at the weekend and filled it to the full line as suggested (old oil looked fine but smelled burnt), but there is no difference in the slipping and it's getting worse, now it will slip will no ballest or wakeboarder behind boat, in reverse if i throttle it hard it does not slip, it just slips in forward gear.

Also the new tranny fluid is still nice and red but does smell a bit burnt after running the above tests.

Any ideas what wrong.

Cheers
ross

[boatech]

RE: Think the Drive is Slipping

how many hrs on it? affraid to say sounds like you have burnt the forward clutches and trans. will need to come out and be overhauled.

[rossl]

RE: Think the Drive is Slipping

390hrs i think.
Cheers
Ross

[boatech]

RE: Think the Drive is Slipping

kinda of low hrs for a failure but it does have some years on it .was it serviced every 100hrs?

[rossl]

RE: Think the Drive is Slipping

It is serviced every 50Hrs, but did spend a good part of its life in the saltwater, but it does have closed cooling so not sure if the salt would effect it too much.

rossl

[boatech]

RE: Think the Drive is Slipping

nah salt is hard on stuff but will not affect that.