regal 4260 goes out of gear

[rick1962]

I have a 2003 regal 4260 with tamd75edc engines and zf 2801v trans I was going down the new river when the engines went out of forward gear. I was able to get to a floating dock and did a check on the edc diagnostics. The lights flashed so I looked in the manual and it said only 2 codes could cause this to happen either a short or open? looking at the alarm module on the port engine the water temp light wasn't lit I tried to test the alarm and that didn't work either? after getting towed in we took the alarm module off the starboard engine and did a swap and found that it worked fine on the port side but the port module that was the problem didn't work on the starboard side either. We also checked the wiring to the engines and found that the wire harness on both engines were loose and had a tie wrap holding them and secured them up. could this cause the problem with the boat going out of gear? Any help is greatly appreciated…..

[DEcruiser]

Did you ever figure out what was causing the transmission issue? Got a 4260 that seems to have the same problem.

[tkeithlu]

You've got some electrical problems to straighten out, but have you demonstrated that the electrical problem caused the slippage? Does it slip out with one harness and not with the other?

Until you answer that question, I'd look at an 18-year old diesel that slips out of gear and explore the shift linkage, since that's a most common cause of slipping out of gear. Disconnect the cable at the tranny and shift manually with the engine running, seeing if it goes in firmly and stays there. Then reconnect the linkage, get someone to shift back and forth at the helm while you watch the tranny, and see if the cable is doing the same thing. Usually the problem is mis-adjustment after the cable stretches or loose tie-downs on the cable sheath.

[DougR]

I don’t recall the exact configuration that Regal used on the tamd 75 engines in the 4260, but most likely it was the standard VP electronic controls with electric shift solenoids on the ZF V-drives. As the OP stated in the first post, you should first check your EDC button panel to see if there are any trouble codes present. Your engine owners manual will tell you how to do that and provide a table of trouble codes and causes.

A fruitful source of problems could be corrosion on the electrical connectors at the shift solenoids, and that’s an easy thing to check/fix. Also corrosion at the other end of the shift harness which connects into the EDC harness. Also, there is the possibility of corrosion or wear in the throttle control potentiometer causing erratic signals to the EDC module. Cleaning the pot and recalibrating the control could be in order.

Lastly you could have a failing shift solenoid on the gearbox.