Prop shaft wobble

[Daybreak]

Daybreak is sick. Turns out that I've got a wobble in the prop shaft. So far the diver has confirmed that the prop and cutlass are in good shape. Mechanic from marine drive shop inspected the shaft and says that I've got about an eighth of an inch run out. At first he thought the shaft was bent but after disconnecting the shaft from the transmission he thinks the registers in where the shaft coupling and transmission flange meet are bad. Either way it's a haul out to confirm, are any of you familier with this?

Capital Gear Transmission
Serial 720630-5
Model 4HE-10200
2:1 Ratio

Ben

[Genesis]

Where does he think it is?

[REBrueckner]

Never heard of a "register". What makes you think its a shaft issue rather than a transmission/engine alignment issue?? Nothing in your post suggests its the shaft. What is the symptom?? Not enough info to make sensible/specific suggestions....

First thing I'd do is see if any engine mounts look askew...worn,drooping,broken,etc. Often an aft engine mount wears out,breaks, slips, etc....and the transmission ends up too low.
Then:
(1) does the shaft coupling fit inside the transmission coupling easily/smoothly?...if the shaft is too high,too low, left or right of the transmission coupling that's a problem. If you have to yank the shart up/down left or right to get the two couplings to mate either the engine mounts or shaft are out of alignment
(2) check four points (top,bottom, left, right) space between the two couplings with a feeler gauge....write down all four results; then rotate the shaft (and it's coupling) 1/2 turn and try again....if the DIFFERENCES among readings on opposite sides change, then the shaft or shaft coupling are out of alignment...top and bottom and left and right should be within 2 or three thousandths for vibration free running but depends on the size of the coupling....
Let's say the top measure is .002" (the absolute value is of no importance) and the bottom is, say, .008".....a difference of .006" or the top is .008 and the bottom is .014....those differences are too much at .006"....if you turn the shaft and get the same difference of about .006between top and bottom then the shaft is straight but the back of the transmission is too low creating more space at the bottom than top....if after rotation, let's say the readings reverse, then either the shaft is bent or it's coupling misaligned...

[Trojan]

Where did he check, how did he check and what did he use to check. Nothing You said relates to tells us anything. It sounds like a eyeball off the wall guess.
Like said what the hell is a register? That's a new one. Maybe it ties in with a bad hemulater wobble bearing."D
BILL

[REBrueckner]

In rereading the original post, if the issue has been properly traced to the transmission/prop shaft flanges, a haul out will accomplish nothing....unless the shaft needs to be removed from the boat for some reason.....

[yachtsmanbill]

I believe the register thats refered to here is a male/female fit on the flanges... my roamer with Velvet drives uses them and the can be misleading when aligning the units. I prefer the face to face type as shown here... There is a slight step on the trans flange that I dont have a pic of... its less than 1/8" though, and that would have to be severely beat up to cause the wobble. ws

[Traveler 45C]

I don’t believe it necessary to pull the pump if you can get to the elbow and just remove that.

[Daybreak]

Yachtsman Bill nailed it, I think. I am still working out the details but this morning the lead mechanic told me about the male/female flange fittings. Additionally, he said if that is what is was then a haul out would not be necessary. After I meet with the mechanic to go over the details I will be be able to discuss specifics more clearly. You are much more mechanically saavy than I am so forgive my lack of knowlege in regards to this issue.