No/Slow shift on ZF transmissions - 2000 48' Sedan Bridge

[Sjspooner]

2000 Sea Ray 48' Sedan Bridge CAT 3196, ZF transmissions

pulled off the dock last week to do a sea trial in CT as boat had been stored on land all winter.

:30 up the river. In/out of gear numerous times at idle. No problems.
Ran at cruise speed for an hour or so. No problems.
:30 at idle back to the dock. Approaching dock in neutral.

when I Re-engaged forward and starboard transmission did not immediately engage. It did after apps 4-8 sec. back to neutral, same when reverse selected 4-8 sec delay. Also noticed the engagement was slow - not the normal clunck into gear.

Went to bed (pissed!).

Next morning started boat boat up and tried the transmission. Engaged forward and reverse 8-10 times with no issues at all.

Thoughts???

 

[ttmott]

Delays in engagement are from hydraulic issues or the shift linkage is not adjusted correctly.
If these are Hurth 800, ZF80 or ZF85 series then and the oil filter cover is not fully sealed the pump will aspirate air and cause shift delays and clutch wear. That cover is a very bad design and many have issues with it. If the linkage is not correctly adjusted or the shift levers are not fully either in forward or reverse the spool valve that directs oil flow can have more than one port open and oil pressure to the clutch packs will be low and flow rate be low so this can also contribute to a delay. Oil level and filter service is obvious. The only other thing is the bypass valve which sets the pump pressure; if it is sticking then oil pressure will be low.
Hope this helps somewhat - Tom

 

[Alex F]

Another thought is, if your transmission is engaging via electrical solenoids (they would be two, FWD and Reverse), then changes are your FWD solenoid is acting up and might be due for replacement.

 

[920richardf]

All the above is good information. I'd start with a check of the fluid level.

 

[Sjspooner]

Well - I feel like an idiot.

Fluid Was very very low. Did a trans service today. Screen on the stb trans was ugly. Port was clean.

Sent out samples. One hour Sea trial ran great. Plan on another change in 10-20 hours.

How much damage did did I do????? Thoughts????

 

[920richardf]

What does "ugly" mean?

 

[Alex F]

Well - I feel like an idiot.

Fluid Was very very low. Did a trans service today. Screen on the stb trans was ugly. Port was clean.

Sent out samples. One hour Sea trial ran great. Plan on another change in 10-20 hours.

How much damage did did I do????? Thoughts????

To me it boils down to these questions:
1. When was the last time the fluid level was checked?
2. If not during the service (not enough fluid was added), then where did the oil go?

Oil samples should give you a clue, but one of the ways for gear fluid to escape is via gear cooler which has internal failure. In this case, there's a great chance for the raw water be present in the fluid. That's where the oil samples should help you identify the issue.

Since you just serviced the transmission, I guess being in the "monitoring mode" is the logical approach. Keep a close eye on the fluid level. I would do another oil sample in 20-30hrs.

What's your reason for changing it in 10-20hrs?

 

[Sjspooner]

thanks all.

Not sure when when it was last checked. Just don't recall.
Clean bilge so where did it go?? Oil analysis should help.

By ugly. A bit of clutch plate (fiber?) in there. No metal pieces - so that's good. Good sea trial afterward.

Change in 10 hours to see how clean the screen is and also to get any residual oil that we couldn't get.

Just wondering if if I caused enough damage to have a failure down the road??? Or just a bit of wear......

won't happen again. Lesson learned.

 

[920richardf]

Monitor the fluid level, but if level holds and no shaft rotation in neutral I wouldn't be too concerned. Might learn something from the analysis that helps you understand the cause of the fluid loss. Hope you'll post any findings.

 

[mistercomputerman]

In the absence of fluid in the bilge, I believe that the only place for the fluid to go would be through a leak in the transmission cooler out the exhaust. You may want to inspect the exhaust on that side, with the engine running at idle, for any oily globules that could show cooler failure.