Alternative lubricant for 2004 ProStar ZF 63A Transmission ? 1:1.5

swbcaswbca Posts: 408 Baller
edited September 13 in Boat Talk
Its standard for this transmission to sound like its filled with loose parts when operating around the dock. My previous 1986 Power Slot and this 2004 196 sound the same.

I have read that's why Master Craft switched to 15W-40 Motor oil for this transmission around 2004. But the rattle is still there.

Before the engine/transmission warm up, there is no rattle with the thicker cooler oil.

Has anyone used a heavier weight oil in this Transmission ?

I wouldn't mess around with a lube that isn't recommended by the factory, unless people experienced with the boat have done it successfully. I know this is a long shot, but just asking.


  • JDskiNECAJDskiNECA Posts: 30 Baller
    I would consider adding a friction modifier 2-4 oz. To see if that quiets it down. They are made by many companies such as Red Line, Torco, AC Delco, Yukon Gear.
    Below is a post from
    "Bob's The Oil Guy"

    site and it is a good description of what is occurring. It is cited at the bottom. I have used the Red Line product in a limited slip rear differential and it quieted it down instantly. I have also used it in a new transmission that had a small amount of torque converter shudder and the shudder stopped in a few miles.

    "Perhaps I can lend some insight to the topic? Before you can understand how friction modifiers function, it is important to understand how "wet" clutches perform. In a wet clutch arrangement, there are three stages of engagement. During the first stage, the clutch is not in contact with the pressure plate or other metal plate. We will use an automatic transmission torque converter as an example. Anyone who has driven auto trans cars with lockup torque converters for a while has probably experienced a phenomenon known as "lockup shudder" or "torque converter shudder". Shudder is caused during torque converter clutch lockup by burnt fluid or fluid wich has exhausted all of it's friction modifers. The result is a chattering feeling when the torque converter goes into lockup mode. I will now attempt to explain the physics of wet clutch engagement. As I have already mentioned, during the first stage the clutch is not in contact with it's mating surface. The fluid itself, however, is acting as a viscous coupling, causing a partial engagement. A side effect of this is heat, and I believe you all know that heat is the killer of automotive oils. The second stage is very simlar to the first. At this point the clutch is very close, possible within thousandths of an inch, from it's mating surface. The viscous coupling is now more effective, but the pressure and shear load on the fluid are also higher, and the result is increased heat. During the third stage, the clutch actually contacts it's mating surface and positive engagement is reached. The shear load of the fluid has been overcome and has either extruded itself outside of the clutch material or, depending on the application, has partly or entirely extruded itself through a porous friction material, thus exiting the engagement area of the clutch. Now that we have an understanging of wet clutch engagement, lets see how that plays out in the real world. If a fluid has lost a substantial amount of the friction modifier, the shear of the fluid will be inconsistant accross the engagement surface and the clutch will briefly alternate between full engagement (stage 3) and viscous engagement (stage 2). The as power through the assembly varies, wich is connected in our case to a vehicle that we are inside of, a bucking of sorts is perceptable to it's occupants as power transmitted to the wheels is momentarely interrupted and regained. In an application like a limited slip rear end, similar phenomena occur but in a slightly different manner. Because the clutch plates are constantly loaded with heavy springs, in theory they should always remain in stage 3 of lockup. If that were the case however, they would never slip. So the purpose of a friction modifier in a rear end is to ensure that the transition from S3 to S2 and back again during cornering etc. is smoothe. Therefor chatter occurs in much the same way it does in our torque converter clutch scenerio. So the answer to your question if friction modifiers enhance friction or reduce it? The answer is there is no answer. Depending on what the application calls for and how it is engineered, they can do either. So as Alex said, it does just that; modifies friction. And now hopefully you will understand why and how as well". [Smile] Pete [ January 06, 2003, 10:09 PM: Message edited by: Pete2k_Z28 ]

    Hope this information helps.

  • DWDW Posts: 2,403 Mega Baller
    For a Velvet Drive the use of hydraulic oil quiets the box compared to ATF. Velvet Drives tend to be much quieter than the ZF so a different starting point. Hydraulic fluid does not have a lot of the detergents found in motor oil which do little for a transmission application. Good luck with your final selection.
  • swbcaswbca Posts: 408 Baller
    @DW @JDskiNECA Does the ZF 63A Transmission have any kind of clutch ? It feels like a crash box and the type lubricants with a clutch are different than for a gearbox without a clutch.
  • DWDW Posts: 2,403 Mega Baller
    edited September 14
    I don't know the inner workings of the ZF, but if it is a crash box (which I really can't think it is just that) some 75W90 would quiet it right down. I assume there is some sort of internal damping mechanism even though it doesn't sound like it from my experience on friends boats. Quick search on a repair kit with photos should answer the question.
  • JDskiNECAJDskiNECA Posts: 30 Baller
    It has a torque converter. The clutches are located inside the torque converter just like on a car with an automatic transmission. The ZF 63 A is a gear reduction trans instead of a 1:1 ratio as in many boats. In gear forward and in gear reverse is it, the torque converter is doing the work.

    ZF 63 A Description:
    Reverse reduction marine transmission with hydraulically actuated multi-disc clutches.

    As discussed in the article I listed above the friction modifiers can be beneficial if you are experiencing torque converter shudder. For about $8.00 you can see if that works. I would start with two ounces. If that helped but did not resolve the issue completely I would add the other two ounces and see how that works. If that does not work then you may be looking at another issue.

    ZF 63

    Torsional Vibration and Torsional Couplings
    The responsibility for ensuring torsional vibration compatibility rests with the overall propulsion system integration responsible party.
    Compatibility check of torsional vibration must include excitations induced by engine governor. ZF cannot accept any liability for gearbox noise
    or for damage to the gearbox, the flexible coupling or to other parts of the drive unit caused by torsional vibrations. Contact ZF for further
    information and assistance.
    For single engine powered boats, where loss of propulsion can result in loss of control, ZF recommends the use of a torsional limit stop. It is
    the buyer's responsibility to specify this option. ZF cannot accept any liability for personal injury, loss of life or damage or loss of property due
    to the failure of the buyer to specify a torsional limit stop.
    ZF selects torsional couplings on the basis of nominal input torque at commonly rated engine speeds. Consult ZF for details concerning speed
    limits of standard offered torsional couplings, which can be below transmission limits. Special torsional couplings may be required for Survey
    Society requirements.

    So if the friction modifier does not work. Based on the above technical data sheet I would surely check shaft alignment and prop that could cause torsional vibration. But based on your description, that as trans warms up it gets worse I doubt alignment is causing vibration.
    If the friction modifier solves your problem great. If not it eliminated one option. The other option is to replace the trans. The trans are about $3000 not installed and with winter coming on I would want to know if I needed to replace a trans over the winter so you are without a boat next year.
    Just my $0.02
  • swbcaswbca Posts: 408 Baller
    edited September 14
    What does a TORSIONAL LIMIT STOP do ?

    a google search of this phrase gets many results . . . . . Page 10 of about 2,960 results (0.44 seconds)

    It looks like ZF has had many transmission model numbers of the years

    My boat had a painful experience
    My nephew is an experienced car driver with lots of experience racing cars on road tracks. I needed a slalom driver a few weeks ago. I was showing him the technique for stopping the boat with a skier on the line at the end of course. His family has an I/O boat but he had never driven a ski boat before. He pulled up the two finger shift lock at 34mph in order to shift into Neutral at the end of the course. He hit reverse at about 30 mph.

    A big CLUNK and the engine killed. I cannot detect any damage. That's a surprise to me.
  • YannisYannis Posts: 3 New Baller
    Use only ATF fluid . All ZF transmissions make noise, more at idle speed. Check the damper plate which is between the motor and the transmission.
  • MastercrafterMastercrafter Posts: 121 Baller
    edited September 14
    Ilmor now recommends Rotella T4 15w-40 in BOTH the 5.7L MPI engine as well as the ZF 45A 1.26:1 trans found in most (all?) late model Prostars. The switch to Rotella oil was supposed to help with noise.

    Edit.. oops.. reading your original post, you're already aware of the 15-40 spec.

  • BraceMakerBraceMaker Posts: 4,915 Mega Baller
    MC/Indmar put out the service bulletin to use 15-40 so it is allowable. But there is another option.

    Whats going on is that your engine has impulses every time it sparks a plug. 4 times a revolution on a V8. Each of these impulses slightly compresses the springs in the flex disc springs which then rebound. All the gears in the trans get kicked by this and they rattle around in there a bit. Once you get off idle the frequency of the impulses goes up, the clutches are engaged, and the output shaft has load these get much quieter.

    But you can get a flex disc with either rubber snubbers or even hydraulic dampening. They cost more and aren't common on ski boats but are very common parts and availaboe for this application.

    If its that annoying a 1200$ hydraulic engine coupler will probably rid you of some of it. But turning off the engine is free.

  • chrislandychrislandy Posts: 277 Solid Baller
    @BraceMaker I put an R&D damper plate in mine when I swapped out the engine a few years ago, fantastic bit of kit and quietened both slow rpm idle and softened the knock in and out of gear - it's now silky smooth.
  • BraceMakerBraceMaker Posts: 4,915 Mega Baller
    @chrislandy yup. Ski boats tend to be worked on my ski boat dealers who dont realize then when your fishing trawler has a 4 cylinder diesel going 450 rpm there is a whole world of much higher quality damper plates.

    The ones sold to us in waterski boats are junk.
  • YannisYannis Posts: 3 New Baller
    The common damper plate lasts 1,000 hours if the springs are greased and not rusted possibly from the water that remains and circulates in the bilge. Bilge pump does not take all the water out.
  • swbcaswbca Posts: 408 Baller
    @BraceMaker Its been decades since I replaced the damper plate on a MasterCraft.

    What's the short bullet point version of this task?. I would be using an upgraded plate.
  • DWDW Posts: 2,403 Mega Baller
    @swbca - Your choice on how to get to splitting the engine from the trans*, then its pretty much like a car clutch swap, remove old plate (6 bolts) & install new plate with new fasteners. Check torque on flywheel bolts. Reassemble, align engine/shaft & enjoy your quiet ride. The trans > engine assembly goes pretty easy, I have never needed a clutch tool to reassemble, at least for a Velvet Drive to GM setup.

    * DD ski boats are pretty simple as far as a powertrain pull. A cherry picker will allow a simple straight lift up & out after all the misc connections are undone then you can do the swap next to the boat. It gives you a chance to do a nice bilge clean up also.
  • chrislandychrislandy Posts: 277 Solid Baller
    taking the tranny out is easy, just remove the driveshaft bolts, loosen/remove the 4 engine mounts jack up the rear of the engine & tranny, block and lift the thing out. It can be done with one person, but 2 is easier!

    I did a damper plate swap in less than 2 hours on my 205
  • swbcaswbca Posts: 408 Baller
    R&D Damper Plate for 2004 / 350 HP EFI MCX Indmar engine

    The R&D damper plate is around $500 according to the USA distributor, They want to know the Horsepower and the Maximum RPM.
    Maximum RPM is not published in the 2004 Indmar Engine Operators manual or anywhere else I can find. And I don't have the boat here to see if there is a RED LINE on the tach.
    Also is HP really 350 or 310 ? There was some debate about this years ago.

  • chrislandychrislandy Posts: 277 Solid Baller
    just tell them the higher value - its the torque and max rpm they're interested in.

    350hp, 350lbft & 5800rpm should do it

    check out the r&d website and the spec flyer

    $500! for once it's great to live buy in the UK, they're around £150-190 here!
  • BraceMakerBraceMaker Posts: 4,915 Mega Baller
    I do dampers by two floor jacks with bar across them and a strap down to the engine.

    Pull prop, loosen 4 bolts on coupler slide back (service strut bushings and seals now if needed) I remove the rear trans mount from the stringers and unbolt the trans from the bellhousing. leaving the trans cooler attached. pull that back and set aside. Then I remove the bellhousing and pull that back. Pop off the old plate attach the new ones. I use a deep socket to center up the plate. Loctite and torque then reverse the process.

    If you have a gantry or cherry picker bug enough you can pull the trans and bellhousing as one part but I find its too heavy and unwieldy together unless you have it hung.

    Agreed about 2 hours if you are prepared. 8 if you keep climbing in and out of the boat for every socket and wrench or find that your rear trans mounts are seized up.

    You will want to realign engine after.
  • DWDW Posts: 2,403 Mega Baller
    +1 on the HP & RPM = 350 & 5800.
  • swbcaswbca Posts: 408 Baller
    edited September 16
    The R&D damper plate cost $425 with shipping from the distributor PYI. The damper has 9 degrees of travel in either direction from center (they call it deflection). They say it fixes the ZF gear rattle and softens the ZF gear engagement. They also make a 30 degree directional model for low rpm work boats . . usually not sold for ski boats.

  • BraceMakerBraceMaker Posts: 4,915 Mega Baller
    @swbca hope it does enough for you!
    The spring ones just get into a harmonic when there is no load on the trans output.

    did PYI give you much feedback?
  • swbcaswbca Posts: 408 Baller
    @BraceMaker He says the R&D damper quiets the gear rattle and softens shifting into gear. Is the noise actually coming from the damper, or is the damper harmonic rattling the transmission ?
  • BraceMakerBraceMaker Posts: 4,915 Mega Baller
    it’s both I was just curious if they knew specifically about zf.
  • chrislandychrislandy Posts: 277 Solid Baller
    @BraceMaker mine is a ZF450 and yes it does quieten down the idle and neutral rattle
  • RayRay Posts: 4 New Baller
    edited September 19
    Double post and my post was shown 2 days later...weird
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