Mastercraft ZF Hurth Issues

Took the 2006 X2 out for the first time today and after about an hour the drive shaft stopped turning and I had to be towed in. When I was left dead in the water it appeared the the tramission/vdrive fluided had pressured up, I could hear hissing from the unit and found some oil misting from around the relieve valve. Now the confussing part is a after a couple hours and the boat had cooled i back the boat into the water and shaft turned when I put in gear. Affraid to take it out agian I put it back on the trailer. I need some help. My first thought is the unit has a high teperature shutdown and the tranmisson has major issues. It appears I have the correct oil level. Any thoughts?

Is your V-Drive and tranny all in one unit or two separate units. If its one unit check as follows. If you pull the dipstick, does your transmission fluid smell burnt. It could be the bands in the transmission slipping causing it to get hot. Your tranny/vdrive cooler could be partially stopped up not letting it cool properly. All this is assuming you kept up with maintenance and topped off fluid levels. You said that you couldn't turn the shaft after it got hot which could mean you fried the bearings as well. Yes they will turn now that its cooled back down, but definitely keep an eye on it. If it is your bands and you have to replace them, I'd have the shop replace the bearings as well. When you were running the boat did the transmission feel like it was slipping at all. If its not your bands, a passage cold be clogged or you may have a bearing going south.

If its 2 separate units, check your v-drive unit for oil level. If its low, fill it up with 30w motor oil and go run it and keep a watchful eye on it because your bearing(s) are going south since you ran it low on oil.

There is no "high temperature" shut down..but it does sound like you have burned up the trans.. IMPO you should buy a rebuilt one or take it to someone and have yours rebuilt. If it got hot enough to lock up then you have damaged clutches along with bearings. I would not try to patch it. It needs overhauled.
You said the oil level was good but what did it look like? Did it appear milky? I have only ever seen these units fail when water gets in them. Not saying it cant happen without water getting in there just curious if it had water in it. Was it milky/clear/brown/red??? Sorry you had some bad luck..Good luck on getting it fixed.

Hope I can help since I went through Hurth Transmission hell last summer. I spent about 20hrs doing google searches and pulled mine out about 4 times before I figured it out. I have a 2002 X-Star so it should be the same. Mine started slipping after the trans over heated. I could drive up to about 8mph then it would slip to neutral. Problem got worse and worse till it wouldn't go into gear. I went to the dealer and their awesome advise was "Just buy a new one, they're only like six grand!" Idiots that sell $100,000 boats and think money has no value.

1. Check to make sure your oil cooler doesn't have little bits of old impeller in it.
2. Replace the tranny fluid.
3. On the port top front side of the trans is an allen head bolt that holds down a round cover. Remove it. Inside is a metal mesh filter. You can replace this for about $80 or just clean it like I did. I used carb cleaner and compressed air to blow out dirt and grime that had built up and completely clogged it up. This turned out to be my problem. A year later and its now working perfectly. Of course I only found this out after I spent weeks cussing at my boat while pulling out the transmission 4 times, having the plates replaced and driving back and forth to the transmission shop 30 miles away trying to figure it out! (Worst case senario, you can replace your plates for about $300, then have your local car transmission shop install them)

Cost: FREE! Take that idiot dealer.

-Just a note, on mine I had the plates replaced and it still wouldn't go into gear. I may, or may not have needed the new plates in the transmission. Wish I would have cleaned the filter first. Like I said, I spent a hell of a lot of time searching for some direction on this thing on-line but really couldn't find much. Hope this helps.

take robs advise. just rebuilt one of mine on my x80. there really is nothing to them at all. if you have to put new steels ands frictions in , mine were the same as a ford c6. if you have some mechanical abilities. you can tackle it no problem. but you will have to take the drum to a transmission shop to load the new steels and frictions in the drum for you

I have a 99 with a hurth all in one unit that makes a metallic rattling sound when in gear. I just purchased the boat 99 230v w 328 hrs a few weeks ago.. Does anyone think this is indicative of problems to come? All my research has led me to changing to 15/40 oil instead of ATF and that these are notoriously noisey tranny's and is normal. Had a tranny oil cooler line leak this weekend and scared the heck out of me as I can't afford a $6000 tranny either!

Originally Posted by bass10after

I have a 99 with a hurth all in one unit that makes a metallic rattling sound when in gear. I just purchased the boat 99 230v w 328 hrs a few weeks ago.. Does anyone think this is indicative of problems to come? All my research has led me to changing to 15/40 oil instead of ATF and that these are notoriously noisey tranny's and is normal. Had a tranny oil cooler line leak this weekend and scared the heck out of me as I can't afford a $6000 tranny either!

When you kill the motor does it continue to rattle a little after the motor stops. If its the one i'm thinking of, yes your right they are notoriously noisy. What your hearing is the pump in the transmission.

Also I've never heard of switching to oil instead of atf. Just out of curiosity, where did you find out about this. I'm not saying your wrong by any means, I've just never heard of it.

I run 15w40 in my zf hurth in my 2003 x2. I believe they changed the recommendation from atf to 15w40 sometime around 2001. I don't think there's any difference in operation except that the transmission is a lot quieter with 15w40. There are lots of threads on it on the mastercraft site.

when i rebuilt mine i used 15 40 the guys at the mastercraft dealership said that the 1540 hold ups better to heat. doesnt thin out as bad as transfluid.

^^^ Thats good to know. Thanks for the info.

my rattling noise only happens when its in gear(forward and reverse) with no additional throttle applied. If i give it even 100-200 rpm more than idle- say 800rpm the noise goes away. If i'm in neutral there is no noise present either. Some mechanics i've talked to say it could be a damper plate and others say its inherent of that tranny. The guy i bought the boat from a few weeks ago says its normal but i don't know if I believe that. He didn't seem to know very much about boats in general...

my transmission is the hurth 630v btw

Originally Posted by bass10after

my rattling noise only happens when its in gear(forward and reverse) with no additional throttle applied. If i give it even 100-200 rpm more than idle- say 800rpm the noise goes away. If i'm in neutral there is no noise present either. Some mechanics i've talked to say it could be a damper plate and others say its inherent of that tranny. The guy i bought the boat from a few weeks ago says its normal but i don't know if I believe that. He didn't seem to know very much about boats in general...

Thats the model I was thinking of. We had one in our previous boat (2004 Infinity Air). Its the pump in the transmission that rattles. In neutral you wont hear it because the pump isn't turning but forward/reverse it does. I dunno why it does it at really low RPMs, but it does.

thanks for the input thomas, it seems to be the consensus here and in the mc forums that its normal- although it sounds like marbles are in the damn thing banging around