ZF 15 MA transmission issues

Jul 1, 2010
962
Catalina 350 Lake Huron
I'm having some shifting issues that have cropped up on the transmission in our 2003 Catalina 350. Transmission is a ZF 15 MA. We're having intermittent problems with it going into forward (usually when cold and motoring out of the slip). Usually, when this happens it acts like it is still in neutral, but I had one or 2 instances the other day where it was obviously slipping. Once it's in gear, though, all seems fine. Boat was new to us last fall. When I winterized it last fall I changed the transmission fluid (dexron) and fluid looked clean then. I recently checked it and it isn't discolored or burnt. Fluid level is fine. I also checked the gearshift adjustment and tweaked things to specs (shifter wasn't quite vertical in neutral but throw in both directions looked fine). Throw is within specs according to the manual (30mm at the bottom hole on the shift linkage each way).

So, it looks to me like the transmission will likely have to come out for repair this winter. I will try changing fluid when we get back to the boat next week, but I'm not holding out much hope that it will make any difference.

Is there anything I'm overlooking, that should be checked? I've read that this isn't an unusual issue with the ZF transmissions. Any recommendations on a good rebuild shop if it comes to that? If it comes down to replacement, is there a drop in replacement that might be a better choice (ie, one of the Technodrive twin disc units)? Thanks for any insights. Pic of trans tag below:

transmission.jpg
 
Jan 11, 2014
11,323
Sabre 362 113 Fair Haven, NY
A few years ago I had a transmission rebuilt by Rick Neary at East Coast Marine Transmissions. East Coast Marine Transmission

Rick was the one of the lead mechanics at Mack-Boring before Mack-Boring got out of the repair and installation business.
 

RoyS

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Jun 3, 2012
1,739
Hunter 33 Steamboat Wharf, Hull, MA
Check lever on transmission for slippage on its shaft.
 
Jul 1, 2010
962
Catalina 350 Lake Huron
Thanks for the suggestions so far. No lever slippage.

East Coast Transmissions looks like a good choice. Dave, was that the gearbox on your Sabre? We have a Westerbeke M35B in our boat so may have similar transmissions? Just wondering how you found the rebuild vs. replacement costs when you did yours.
 
Jun 15, 2012
694
BAVARIA C57 Greenport, NY
I would be absolutely sure that you are using the correct fluid in the transmission. Did it work OK last year, before the fluid change? If so the only thing that changed is the fluid. Perhaps it is just the brand of fluid or a different spec.
I had a transmission rebuilt 5 years ago by Rick and cannot recommend his work more highly.
 
Jul 1, 2010
962
Catalina 350 Lake Huron
I would be absolutely sure that you are using the correct fluid in the transmission. Did it work OK last year, before the fluid change? If so the only thing that changed is the fluid. Perhaps it is just the brand of fluid or a different spec.
I had a transmission rebuilt 5 years ago by Rick and cannot recommend his work more highly.
I used Dexron III which is recommended in the Westerbeke manual. Don't have last year to compare to as we bought the boat just before I had to winterize it. It was fine almost all summer. We took a trip from Lake Erie up to the north Channel of Lake Huron and back, and noticed the problem intermittently on the way back. We put around 1200 nm on the boat on that trip and about 160 hours on the motor during that time. The engine had 690 original hours on it when we bought it, so it got used more this season than it probably ever has. We did more motor sailing on that trip than we like, but beating across Lake Erie is not a lot of fun and sometimes you just have to motor point to get there in a reasonable amount of time. Also, lots of motoring up and down the Detroit and St. Clair rivers.

My thought is to try a different brand of ATF (same spec) but we're quickly running out of sailing season to really test things. Since it seems to be getting more consistently worse, it shouldn't take too many trips to confirm the problem is still there.

Also, Westerbeke had a service interval in the book for engine oil and transmission oil change intervals of 250 hours, so I didn't think I had to worry about changing the transmission oil sooner as we won't hit 200 hours this season. Maybe I should have rethought that plan.

When sailing, I've always let the transmission free wheel in neutral. Manual said that is ok. Just was very specific that you don't leave it locked in forward (neutral or reverse being ok).
 
Last edited:
Jan 11, 2014
11,323
Sabre 362 113 Fair Haven, NY
Thanks for the suggestions so far. No lever slippage.

East Coast Transmissions looks like a good choice. Dave, was that the gearbox on your Sabre? We have a Westerbeke M35B in our boat so may have similar transmissions? Just wondering how you found the rebuild vs. replacement costs when you did yours.
I have a Yanmar with a Kanzaki transmission, which is a very expensive transmission to replace. A new one goes for about $6 or 7K, the rebuild with a new damper plate was around $1500. I did the remove and reinstall. If you pull the transmission get a new damper plate, they are only about $100. As I think about it, the symptoms you describe might be related to the damper plate. I am far from an expert on transmissions, so consider this as an idea that needs expert confirmation.

The damper plate sits between the engine and the transmission and dampens the jolt when the boat is put in gear. If the plate is starting to fail, it might cause slippage. When the plate warms up and expands, then it slips less.
 
Jul 1, 2010
962
Catalina 350 Lake Huron
Thanks for the link to the list of fluids. Always a challenge to take the European lists and try to figure out what the same manufacturer is calling the name in the US market.

Concerning the damper plate, our boat does have the typical damper plate rattle at engine speeds below about 1100 rpm. Seems to be a pretty common complaint with the Westerbeke M35B engines. Not sure when the rattle is considered too much. Will definitely replace the damper plate when / if the transmission comes out.