View Full Version : How do you change gear oil in the gear box

06-17-2009, 10:33 PM
Jan and I have a 1995 Maristar 225, and we love the boat. We maintain the boat to the best of our ability, and the dealer in Austin says that they may see around five boats a year that are maintained as well as ours. However, I was thinking about our V-drive gear box recently, and consulted my owners manual to learn about recommended maintenance. I discovered that, even though I have read the owners manual many times, there is no mention of the v-drive gear box. In fact, there is no mention of the v-drive gear box in any of your owners manuals. My drain plug and overflow plug have now been in place for so long that I can not loosen them. The plugs are square male bolt heads(plumbers plugs). First, why do you not address the v-drive gear box in any of your maintenance guides, and, second, how would you recommend that I loosen the gear case drain and overflow plugs? How much volume does the gear box hold? What gear lubricant is recommended for the unit? Finally, since you do not reference the gear box in any of your literature, I am sure that there are many boats which have never had any service completed on the box. Help! How can I loosen these bolts and service my gear box?

06-18-2009, 05:52 AM
Bear in mind that this site is MasterCraft-sponsored, but MasterCraft rarely participates. The members of this forum are mostly just plain ol' MasterCraft owners like you, and we all pool our knowledge. There are a few dealers that participate too, but not as representatives of MasterCraft.

Can't answer your questions without knowing what transmission you have. It's either a Hurth V-Drive, or a Hurth in-line transmission with Walter's V-drive unit. It's important to know because these are completely different transmission concepts with different maintenance requirments. The Hurth V-drive is all one unit and wants ATF, whereas in the other scenario you'll need ATF for the transmission and motor oil for the Walter's V-drive. Maristar 225's of that vintage might use either setup.

The separate V-drive concept (Walters) hasn't been used by MasterCraft (Indmar) in many years. All the V-drives these days use Hurth V-drive single unit transmissions. The transmission oil on those is changed by pumping the old stuff out through the dipstick hole, then refilling with either ATF or 15W40. I don't know how the oil is changed in a Walter's unit. Hopefully, someone will come along in this thread that owns one and can shed some light.

If you want to maintain your transmission, you'll need to go find out what kind of transmission you have. The basic maintenance procedures are outlined in the Indmar owner's manual. If you don't have one, you can download it here (http://www.indmar.com/About/ContactIndmar/Manual1994_2002web.pdf).

Supposedly there is a separate owner's manual for the transmission that should have come with your boat. I got one for my Hurth V-drive. Maybe there's one for the Walter's unit, if that's what you have. Their web site and contact information is here (http://www.waltergear.com/). There's a "maintenance manual" downloadablehere (http://www.pearson40.org/v%20drive%20manual%20pages%201%20thru%203.pdf) and maybe here (http://www.pearson40.org/more%20walter%20info.pdf). If you have that unit, and need more info, maybe you could call them.

Get back to us once you have the specifics on your transmission and maybe we can answer your questions better. Otherwise we'd just be guessing.