ZF 15 MA Hurth - stiff shifting

[phantomracer]

Noticed the last few seasons, the shifting has been a bit stiff going into forward or reverse, or back into neutral on the ZF 15 MA mated to the 3GM30f engine.

Is there any normal lubrication points for the shifting that needs attention? I will look at the edson levers and the cable, naturally. Was not sure if there is any lube points on the transmission itself.

Also

I can't find any best practices on changing out the transmission fluid (atf). I know it is about .5 qt, I am unsure how to get the old fluid out, suck it out through the dipstick hole?

[Greg4cocokai]

Hi, I would disconnect the cable from the transmission first and see if it’s still hard. Then I would check the cables for any abrasions through the outer coating and then check just the lever at the pedestal. The cables are pretty cheap and easy to replace.
My newest boat the lever was very stiff and it took me a while to get it loosened up. Good luck

[PippaB]

Here's a capture of the manual on the fluids and changing. There should be a drain bolt on the bottom side, takes a 17mm socket/wrench/spanner (same as the dipstick).

There is also a procedure for adjusting the shift lever on the transmission, but not for lube. In the past we've always found that our problems were in the cables/shifter rather than at the transmission. If you disconnect at the transmission and shift by hand it does take some force to move through the forward and reverse detents, you will feel them as the lever drops into position.



Here's the 15M drawing showing the dipstick ('b') and drain plug ('d'). The manual says the exact same things about the 15MA, but the diagram from the MA does not have 'd' labeled (it is visible), and I don't have the MA, but AFAIK they are all the same in that regard.




I do have the repair manual in PDF if you want to PM me, it is too large (2.8MB) to attach in a post here, and the library feature takes forever (sometimes longer) to get through approval.

[phantomracer]

Originally Posted by Greg4cocokai

Hi, I would disconnect the cable from the transmission first and see if it’s still hard. Then I would check the cables for any abrasions through the outer coating and then check just the lever at the pedestal. The cables are pretty cheap and easy to replace.
My newest boat the lever was very stiff and it took me a while to get it loosened up. Good luck

Thanks.

The cables were installed around 1992, so that is my first guess. I wasn't sure if there was any known issues with the box itself.

Once it is on the hard, I will tear into it. Probably replace the cable (well both of them), just because of its age.

It is an edson pedestal, I will check the levers and such as well.

[phantomracer]

Originally Posted by PippaB

Here's a capture of the manual on the fluids and changing. There should be a drain bolt on the bottom side, takes a 17mm socket/wrench/spanner (same as the dipstick).

There is also a procedure for adjusting the shift lever on the transmission, but not for lube. In the past we've always found that our problems were in the cables/shifter rather than at the transmission. If you disconnect at the transmission and shift by hand it does take some force to move through the forward and reverse detents, you will feel them as the lever drops into position.

Attachment 263981

Here's the 15M drawing showing the dipstick ('b') and drain plug ('d'). The manual says the exact same things about the 15MA, but the diagram from the MA does not have 'd' labeled (it is visible), and I don't have the MA, but AFAIK they are all the same in that regard.

Attachment 263984


I do have the repair manual in PDF if you want to PM me, it is too large (2.8MB) to attach in a post here, and the library feature takes forever (sometimes longer) to get through approval.

Thank you. I saw the manual page. I didn't see in it that there was a drain. Good to know. I will look at it next time I am on the boat.

I am going to replace the cables...and inspect the shifters themselves. so there is no common problem with stiff shifting, great to hear. I didn't want to fire up the parts canon right away if there is something else to investigate.

I haven't changed the oil since I got the boat (14 seasons) so I guess it is due! Color of the fluid looks good. I assume that I still should make it a point to change it regularly.

I did find the manual pdf online. Looking at it now

[phantomracer]

Also, if I remove the drain plug, is there a washer or o-ring that needs to be replaced?

[PippaB]

Yes, there is a copper washer on the drain plug (and on the dipstick). Pretty much no reason you can't go to the local (decent) hardware supplier and get one of the same size. Since the dipstick is the same size (and even the same part number for the seal washer) you can pull that to get size without draining the ATF (sorry, I have notes somewhere on that size, but can't find them at the moment).

New part # 3306 301 016 (they changed part numbering systems at some time)
Old part # 326578

[capt jgw]

Stiff shifting (or throttle) is almost always corroded or abraded cables. The control lever itself could be stiff but a shot of spray grease should fix that. If the trans itself is stiff, that's a problem. As said above, disconnect the cable at both ends and see that the control lever and trans lever move freely. Depending on routing, replacing the cable should pretty easy, tape new to old and pull it through. Hopefully nobody used zip ties and cinched them up tight where you can't get to it.

[phantomracer]

OK Long overdue update for this!

Got the cables out, they seemed OK..but a bit notchy, nothing that would account for the very stiff shifting and throttle.

The controls on the engine seemed smooth.

The Edson pedestal controls were very still. This is likely the culprit.

Since the cables are AT LEAST 22 years old, I decided to replace them, since I was in this deep. I wasn't going to use 2+ decade old cables again.

I happen to be local to Edson, so I got 2 new cables from them, and dropped off the shifter/throttle control from the pedestal for them to rebuild (likely just needs new nylon bushings)

Of COURSE the bronze base UNDER the pedestal was made for the old cables to fit PERFECTLY. The new cables are .5mm thicker! They wouldn't fit through the holes.. so I had fun drilling the hole a smidge thicker (1/2") which the new cables JUST fit through!

Seriously, I am sure the people at edson were laughing as I tried to remove the cables from the pedestal! I found removing one of the bronze wheels from the cable under the deck, allowed slack that I could lift the chain off the gear in the pedestal to get the cable bracket through!

At least Edson services their products! This pedestal was from 1977, still in pristine condition!

So the cables are in, Just waiting for the pedestal mount to come back from Edson! Then I will mount the cables to the engine and controls and check for proper operation.

[phantomracer]

Originally Posted by phantomracer

Thanks.

The cables were installed around 1992, so that is my first guess. I wasn't sure if there was any known issues with the box itself.

Once it is on the hard, I will tear into it. Probably replace the cable (well both of them), just because of its age.

It is an edson pedestal, I will check the levers and such as well.

Update, cables installed in 2001 when the new Yanmar engine was installed. My bad

[phantomracer]

Just a follow up to this thread.

Changed the transmission fluid today! First time since it was installed (2001)!

Yea.. it was due!

Guess I will not wait 2 decades (well 15 seasons of use) to change the fluid again! Just a wee bit dark!

Access was horrific getting to the drain plug! with the curve of the hull, could only get maybe 1/8 of a turn of the socket! after a few turns, the socket got stuck, had to put it back a bit, and finish with a wrench! the threads were a bit crunchy, so the plug didn't come out smoothly. Eventually it did. drained it into a gallon zip lock bag. saw no shavings or any sediment in the bag. Other than being dark, it looked fine. Got to love the smell of used transmission fluid!

Joys of boat ownership! At least i know what I am up against.

[capt jgw]

I just suck it out through the dipstick hole with the same pump I use on the engine oil. Doesn't get it all out but good enough.

[phantomracer]

Originally Posted by capt jgw

I just suck it out through the dipstick hole with the same pump I use on the engine oil. Doesn't get it all out but good enough.

thought of that. might do it that way from now on. If I do it more often, but do partial changes, might be better than a bi-decadal fluid change!

[Mickeyrouse]

Have a Hurth ZF, it had similar problems. Changed the cable. Be sure the cable is not pinched or otherwise restricted. Apply grease to the shafts at the ends of the cable, work it a few times to allow it to move the length of the cable.

[phantomracer]

Originally Posted by Mickeyrouse

Have a Hurth ZF, it had similar problems. Changed the cable. Be sure the cable is not pinched or otherwise restricted. Apply grease to the shafts at the ends of the cable, work it a few times to allow it to move the length of the cable.

They were replaced, and had the pedestal controls serviced , which fixed the problem. Still, needed to change the fluid, was pretty bad!