View Full Version : Dextron or 15w 40 and filter question.

08-09-2012, 11:39 AM
Ok Here is my question. My tranny is slipping a little when i first put it into reverse and i was going to replace my fluid I looked at what was in it and im not real sure if it is Dextron or 15 40. I looks like it could be the dextron and just dirty enough for it to look brown im just not sure. Does anyone have a recommendation on one over the other or which might help a little slipping problem? Also lets say it is full of dextron, If i were to switch to 15w 40 how would i go about the switch? ALSO! Where is the filter.. If it has one and does anyone know a part number for the filter? Thanks in advance.. I pray for some help thanks.

08-09-2012, 12:04 PM
?Boat? Transmission? If velvet drive, you need ATF, not motor oil. There is no filter on the transmission, that I know of, only a fluid cooler. I am speaking of what I know about my boat which is a '94 prostar w/ 1:1 velvet drive.

08-09-2012, 12:15 PM
? Wat tranny is yours. I"ve got a 1:1 BW Velvet dr. No filter fluid is pink in color Dextron.

08-09-2012, 12:15 PM
Its an 05 xstar with the 8.1L Motor not sure what the tranny is. sorry should have included it in the original post.

08-09-2012, 04:00 PM

08-09-2012, 07:16 PM
I don't know bout your boat but I switched over from the dexron to 15-40 in my Trans. Pumped it out through the filter hole and replaced filter. 2001 PS 205v LTR with hurth 630v1-15.5 Ratio 1.56
Service advisory stated to switch to quiet slight rattle. Do research on your model. Someone here who knows more will most likely chime in.

east tx skier
08-09-2012, 10:00 PM
Whatever is in there, you probably want to use the 15W40. If in doubt, change it a few times. until you have no doubt that it is motor oil.

08-10-2012, 12:04 AM
See page 67 at http://mastercraft.com/files/manuals/2005_MasterCraft_Owners_Manual.pdf. Looks like 15w40 is recommended. It also explains the location of the transmission filter.

Don't know the filter P/N but perhaps you can identify the transmission you have. On later models the transmission have a faceplate towards the front that have the model number.

08-10-2012, 04:40 PM
does anyone know if rotella will work or my other option is mobil Delvac both are fairly high quality non synthetic oils anyone think there would be a problem with these?

east tx skier
08-10-2012, 07:17 PM
Don't know why it wouldn't work.

08-13-2012, 02:22 PM
Your third option could be Chevron Delo 400 LE. It's what my local dealer uses and what I use in mine.