View Full Version : Transmission Fluid

09-28-2009, 08:33 AM
I changed the transmission fluid this past weekend for the first time on my 20005 x10 since I bought it last year. The spec sheet said to use 15w 40 but when I pulled the old stuff out it was green with a strong odor like coolant. I put 15w 40 in like the spec sheet said. Is this ok, or should I have replaced it with the stuff that was already in there?


09-28-2009, 08:55 AM
The stuff that was in there should have been 15W40, same as what's in your engine.

Don't know why you'd have any kind of coolant in your transmission. Do you have closed cooling on your boat's engine?

09-28-2009, 09:02 AM
I donít think it was coolant but it had that same look and smell as coolant

09-28-2009, 10:01 AM
There's no earthly reason why a transmission would have antifreeze in it, except maybe for a massive screwup during winterization, or a closed cooling system with a leak in it.

09-29-2009, 04:32 AM
Do you put motor oil in the tranny??

09-29-2009, 06:04 AM
I did. After draining whatever that green stuff was I placed 15w40 in like the maual said to do

09-29-2009, 01:54 PM
There can be one of two things in the Transmission:
15w-40 Motor Oil
Hurth specifies ATF, and Hurth in combination with Mastercraft have accepted 15w-40.

Neither one is green, or smells like coolant. Neither one will turn green and smell like coolant if it gets old. Neither one will turn green if water (the most probable contaminent) gets in it. Based on your report, Ed, I've got to agree with bigmac - somehow, antifreeze (the poisonous kind) got poured into your transmission.

First, I'd figure out where it came from. If you don't have a closed cooling system, it had to come from some human who poured the wrong thing in the wrong place. If you do have a closed cooling system, it's either the same issue, or you have a leak in the transmission cooler that's allowing coolant into the transmission. Either whack the human upside the head, or repair the hardware.

Second, I'd flush it several times. Fill it with oil, drain and refill. Run it a few minutes in gear, drain and refill. Run it for half an hour, drain and refill. Repeat step 3 until it comes out looking like motor oil.


09-29-2009, 02:03 PM
Any possibility that this is synthetic oil of some kind? A long shot for sure, but I had to ask.

09-29-2009, 07:02 PM
Could be green oil. I've seen brown, blue, purple, red, green oils, but none of them smell like coolant.

09-29-2009, 07:11 PM
To be more specific, since about 2001, Indmar has said it's OK to use 15W40 in gear reduction transmissions (such as all the current V-drives) as a means of decreasing a cosmetic problem with transmission rattling at idle. ATF is OK, but those ZF Hurth gear reduction trannies come from Indmar with 15W40 in them, and there's no point in switching back to ATF.

It is true that some oil has a green tint, but the bright lime-green color of antifreeze in the transmission isn't appropriate.