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Transmission Maintenance Schedule

Posted: Sat Jan 20, 2018 2:19 am
by AMCarter3
Does anyone have a schedule for routine maintenance on the ZFE-25 Transmission? I assume this transmission is on most of our PDQ boats. I have the ZF operating manual, so I understand what I'm supposed to do. What I don't see is a maintenance schedule like you would find in the Yanmar engine operating manual. Is there a routine schedule for changing the oil and filter?

Re: Transmission Maintenance Schedule

Posted: Sat Jan 20, 2018 7:13 am
by SecondWind
According to ZF there is a reference plate on the transmission (page 2): https://www.zf.com/global/media/en_zf/l ... -ML_04.pdf

Re: Transmission Maintenance Schedule

Posted: Sat Jan 20, 2018 8:24 am
by duetto
hi,

we change oil and filter once a year.

Re: Transmission Maintenance Schedule

Posted: Sat Jan 20, 2018 11:30 am
by AMCarter3
It's interesting... I've posed this question to a bunch of experienced power boaters with ZF or other brand transmissions and everyone gives essentially the same generic response - "I don't know of a schedule; we just change the oil every year along with the annual engine maintenance." And, no one sends the oil out to be tested. Seems odd to me.

Re: Transmission Maintenance Schedule

Posted: Tue Jan 23, 2018 2:20 pm
by deising
I agree, Mac, that my attempts to find the same info have been unsuccessful. I change about every 500 hours or so. I have never sent the oil out either.

Re: Transmission Maintenance Schedule

Posted: Tue Jan 23, 2018 9:44 pm
by AMCarter3
I met with our local diesel experts (Tri County) about this. First, it was interesting to hear them say they do not follow the ZF recommendation of changing the Trans oil every year. (Note that most of the power boaters I know do follow that schedule). Tri County changes the Trans oil every 2 years or 1000 hours. Second, they did said the metal mesh filter does not need to be changed. They said I "could remove it and clean it with solvent" IF I wanted to do so, but they said with this small ZF-25 transmission, that it isn't really necessary. Just making sure the oil level is correct is pretty much enough.

I changed the trans oil in both engines today... took 2.5 quarts each to fill them to the "max" line. I tried but could not budge the top of the filter holder. So, I skipped it and stopped worrying about it.

Re: Transmission Maintenance Schedule

Posted: Wed Jan 24, 2018 3:06 am
by John&Ria
Hi Mac,

We had the transmission fluid and filters replaced last year, and have been doing it about every 2 years since we purchased the boat. I believe the ZF manual I have says every 1000 hours.

I also heard from Tri-County when I purchased the parts in Bellingham (cheaper than in Vancouver) that it was not necessary to replace the filters unless damaged. Our mechanics in Vancouver, who we've been with for a long time, strongly recommended against this however. They say it's difficult to get them properly clean and not worth the risk.

Clearly there is some difference of expert opinion out there.

John

Re: Transmission Maintenance Schedule

Posted: Wed Jan 24, 2018 11:12 am
by AMCarter3
Good to know, John. Thanks. I'm still "averaging" all the different points of view about the timing and whether or not to clean or replace the trans filter periodically. It's interesting that there such a range of views on this -- boaters, tech pros, and web chat forums such as <http://www.mastercraft.com/teamtalk/archive/index.php/t-7375.html>.

Re: Transmission Maintenance Schedule

Posted: Wed Jan 24, 2018 1:02 pm
by deising
Well, you can't get doctors and surgeons to agree on many things, either.

Re: Transmission Maintenance Schedule

Posted: Mon Jul 02, 2018 7:32 pm
by Expatriate
I am thinking of having my props repitched. Currently, under power with the 75 hp engines, I can only reach about 2800 RPM. There may be other factors such as total load of fuel and water. However, an inch of pitch off both props is not a huge change and it may keep the port engine from running on the hot side. So I wanted to do this while the boat is out of the water for a bottom job.

I went to my local prop shop, and the guy wanted to go through the entire calculation for diameter and pitch. So he is being thorough. One question was the transmission ratio so I went to the boat to have a look. I could find no information whatsoever, not even the manufacturer. The engine owner's manual is all I have and it lists: KBW21, KM4A, and KMH4A. I found a picture online of a ZF25 that looks like my transmission. It even shows the location of the nameplate, but I could not find it on my transmission.

This is very strange. Any info would be helpful.

Tim
M/V 068

Re: Transmission Maintenance Schedule

Posted: Tue Jul 03, 2018 11:19 am
by Expatriate
Well, after finding nothing on the port transmission, l checked the starboard. Sure enough, there was the little plate proclaiming ZF-25. Gear ratio for the “A” and “B” positions are 1.97. Wonder what happened to the port side label? I will let you know how the repitching goes.

Tim
M/V 068 Expatriate

Re: Transmission Maintenance Schedule

Posted: Sun Jul 08, 2018 3:27 pm
by Cat Daddy
Tim,
I have been down this road, here is what I learned. Be sure the engines are running properly before chasing prop pitch. My injectors had slowly degraded, not allowing the engines to develop full horsepower, so the changes to the props did not really help. After the injectors were repaired the original pitch was about right. Turbos that do not develop full boost would also be an issue.

Good luck.

Re: Transmission Maintenance Schedule

Posted: Sun Jul 08, 2018 9:35 pm
by Expatriate
Thanks Rafe. The prop guy had similar comments. Since the boat will be out of the water anyway, the prop guy has said we should bring the props in to check for damage. Then we will go from there.

Tim

Re: Transmission Maintenance Schedule

Posted: Wed Jul 11, 2018 1:22 am
by AMCarter3
Tim,

I agree with Cat Daddy... prop pitch is only one of several factors that influence performance and probably not the biggest one. We took 5 actions last winter to improve the performance of our 100 HP engines: 1) test injectors (we had to replace all 8); 2) adjust the valves properly; 3) find and fix an oil leak in the port oil cooler; 4) pull the running gear, replace both cutlass bearings and have the shafts tested and any alignment issues corrected (one did need serious correction); and 5) reduce the pitch on both props to 17x13.

The net result was a 400 rpm increase (3400 to 4000), much quieter engines, and a 1.5 knot increase in top end speed.