ZF transmission stuck in forward

[Ezsteps]

I tried searching the forums but not seeing anything. My buddies 98' 400 DB portside transmission is stuck in forward. With the engine off when you move the shifter you can see the linkage move, but when you start the engine the transmission stays in forward. With the engine running when you shift to reverse the engine stalls. It a ZF transmission. Anyone ever have this happen? Seems like something internal to me. TIA

 

[ttmott]

It appears the forward clutches have been slipping and overheated then warped and now are stuck together. Placing in reverse then locks up the gear and will stall the engine. Does the ATF smell burned? Slipping clutches can occur if the shift mechanism is not adjusted correctly or the shift levers are not fully engaged when used.

 

[Ezsteps]

Thanks ttmott, we were actually underway when it happened. You could definitely smell burnt once things went funky. We came in the final 10 miles on one engine. Once we got to the dock and got out of the 3 to 4 footers we were able to diagnose what was actually happening. Sounds like it needs to be pulled and repaired right?

 

[hottoddie]

In todays R&R world most marine mechanics want to replace instead of rebuild marine transmissions. Either they lack the skills or just don't want to take a chance of having to remove it later if their rebuild doesn't perform as it should.

 

[Ezsteps]

Update: it appears ttmott and hottoddie are on to something. Mechanic pulled the transmission and feels the clutch plates are warped and stuck together(ttmott) and recommended just getting a new one(hottoddie). They do not rebuild transmissions, they outsource it. I should mention that the mechanic is from CAT so it don't surprise me that they outsource transmissions. He gave my buddy a few numbers/recommendations. So now my buddy is doing some research and trying to figure out what he wants to do next. Do any of you have any input on where to get a replacement transmission or any input on rebuilding? This transmission thing is uncharted water for me so sorry if I sound like a newbie.

 

[ZZ13]

I helped a buddy replace the ZF 280A starboard transmission on his 2001 400DB. The transmission oil cooler failed and sucked all the transmission fluid out the exhaust with the seawater cooling water. Have him replace both engines transmission oil coolers as part of this if they are more than 10 years old.

We got the transmission from a local shop. The shop first tried to rebuild it but couldn't get it apart. So he bought a new one and we did the remove/install ourselves. Hardest part was rigging up a jack under the engine to jack it up to get the engine mount bracket on the transmission to clear the engine mounts. Other than that, they are heavy.

 

[LG111]

Not sure where you are located but I live in the Seattle area. North of Seattle in Everett you can buy new hurth trannys. I replaced my port v63 with a new trany. Two year warranty and only 3200 buck. Forget the rebuild!
I'd call these guys and find out where there is a dealer near you? Or have them ship you what you need. Good guys there!

https://www.harbormarine.net/services

 

[Ezsteps]

Thanks LG111, I'll pass on the info.

 

[Boat Guy]

Always learning something new...