I know everyone's initial response is we need more information, but I need to know where to even start looking for what I believe to be a transmission problem. Haven't even started looking into the problem as it didn't show up till the end of the weekend. It's a Ford 427 mated to a Paragon transmission, straight inboard. All of a sudden this weekend, sporadically, when shifted into reverse the motor would shut off. I don't believe this to be a motor problem as it fires up again immediately, without any fuss. Its not occurring every time I shift into reverse, but maybe every 2-3 times (of course, docking becomes interesting). Where should I start for a diagnosis. Just had the reduction gear rebuilt this past year, but haven't been having any problems with the transmission till this past weekend. Has not happened at all when shifting into forward, only reverse.
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Transmission Problem
- Thread starter LBDboater
- Start date
Being a 1966, there is no neutral lockout switch, she starts in gear if you want. The throttle and transmission shifters are separate, but maybe something rubbing on something and grounding out. There really is no interface link between the transmission and the engine on this. Purely mechanical nuts and bolts more or less.
Is the fluid at proper level & smells OK?
Mostly non-transmission stuff:
As a long shot, at the dock with engine off & in N you might go under and see if there is any difference in effort to turn the wheel CW or CCW. Sometimes fishing line or larger will wrap the shaft in one direction and at low torque rpm may allow it to turn one direction much easier than the other. Take a waterproof flashlight and get a good look at both ends of the cutlass.
At what RPM does it idle in N & in gear ? Could that be slightly too low? Does the tach rpm vary much at idle is it steady?
Does it only manifest when you engage reverse when the boat is still moving forward so prop direction has to reverse from fwd rotation even if it was in N? Or can it happen at rest at the dock going from N to R?
As Mike says, see if there could be anything in the ign. circuit that is chafed or tugged by the control movement. Kind of hard to picture that though.
Mostly non-transmission stuff:
As a long shot, at the dock with engine off & in N you might go under and see if there is any difference in effort to turn the wheel CW or CCW. Sometimes fishing line or larger will wrap the shaft in one direction and at low torque rpm may allow it to turn one direction much easier than the other. Take a waterproof flashlight and get a good look at both ends of the cutlass.
At what RPM does it idle in N & in gear ? Could that be slightly too low? Does the tach rpm vary much at idle is it steady?
Does it only manifest when you engage reverse when the boat is still moving forward so prop direction has to reverse from fwd rotation even if it was in N? Or can it happen at rest at the dock going from N to R?
As Mike says, see if there could be anything in the ign. circuit that is chafed or tugged by the control movement. Kind of hard to picture that though.
Fluid levels are in good shape, I have been able to check that. It does it both from a rest in to reverse (the first time it happened was leaving the dock, twin reverse to back out and she stalled but fired right on up) as well as with forward momentum. RPM is good, seems steady. I'm never willing to count anything out, but I would be shocked if I find that this has to do with the ignition circuit or improper grounding-out of something (the cable has to move to shift into forward, and we've shifted in forward way more times already than reverse with no stall). I guess I'm on to looking for something underneath, and not loving the idea of diving into the water right now (still pretty damn chilly). We are going to check the alignment of the reverse gear with the reduction gear (they are two different "parts" bolted together) to make sure that something isn't binding there and causing the engine to stall. As of right now, we aren't planning on running the boat until we come up with something. Really appreciating this input from everyone.
- Joined
- Dec 16, 2003
- RO Number
- 12563
- Messages
- 529
Interesting problem. First, congrats on the 427 Fords. Very nice engines. Maybe not high tech but with care will last forever.
I'd ask, "what has changed" since everything ran satisfactorily? You had the reduction gear rebuilt. That's the first place I would look. Those Paragon reduction units are just gears running in oil but if they are not put back together just right, that could be a problem. Any over spec runout on the gear sets could, I guess, have the lockup effect that you are describing. That's just not a common problem with those gears unless whoever rebuilt them didn't do it properly.
When you say it only happens in reverse, that makes me suspect the reduction gears even more. The reversing takes place in the transmission (aka reverse gear). The torque applied to the reduction gear in reverse actually makes the gears operate in the opposite direction, so if everything isn't aligned properly, it's possible that the reduction gear is locking up from time to time. Given the age of those units, that's not something that you want to repeat very often.
I may be wrong about this but if I were you (after short hauling to make sure that there was no line caught in your prop) I'd take out the entire Paragon transmission/reduction gear unit and have it inspected. If there is any run-out on the reduction gears, have that corrected. Then flush out all the old transmission oil.
Bill
I'd ask, "what has changed" since everything ran satisfactorily? You had the reduction gear rebuilt. That's the first place I would look. Those Paragon reduction units are just gears running in oil but if they are not put back together just right, that could be a problem. Any over spec runout on the gear sets could, I guess, have the lockup effect that you are describing. That's just not a common problem with those gears unless whoever rebuilt them didn't do it properly.
When you say it only happens in reverse, that makes me suspect the reduction gears even more. The reversing takes place in the transmission (aka reverse gear). The torque applied to the reduction gear in reverse actually makes the gears operate in the opposite direction, so if everything isn't aligned properly, it's possible that the reduction gear is locking up from time to time. Given the age of those units, that's not something that you want to repeat very often.
I may be wrong about this but if I were you (after short hauling to make sure that there was no line caught in your prop) I'd take out the entire Paragon transmission/reduction gear unit and have it inspected. If there is any run-out on the reduction gears, have that corrected. Then flush out all the old transmission oil.
Bill
Thanks, I see from your name you have a 67 Chris Craft, these are in a '66 Chris Craft 40' Constellation. We can attest to lasting forever (damn near bullet proof has been our experience), they have around 2400 hours and have been submerged and still the original blocks with just a top end job completed and a lot of electrical work.
The transmission was shipped up to a guy who has always done great work on the Paragons for us in Massachusetts, (Boyd, I think is his name)(we're in VA, freight ain't cheap anymore). We're hoping it's something simple, but I'm just preparing thought wise for something more major as far as troubleshooting. Plan on looking at some minor things this weekend and if that doesn't pan out, then having our mechanic down next weekend. Not planning on using her until we come up with something we "think" is the problem. We've been using the boat for the last month, so this just occurred randomly this weekend for the first time, but this isn't her first weekend out.
The transmission was shipped up to a guy who has always done great work on the Paragons for us in Massachusetts, (Boyd, I think is his name)(we're in VA, freight ain't cheap anymore). We're hoping it's something simple, but I'm just preparing thought wise for something more major as far as troubleshooting. Plan on looking at some minor things this weekend and if that doesn't pan out, then having our mechanic down next weekend. Not planning on using her until we come up with something we "think" is the problem. We've been using the boat for the last month, so this just occurred randomly this weekend for the first time, but this isn't her first weekend out.