Bent prop shaft

During the week of the 4th. I pulled my boat to the White
River to trout fish. The last day I hit something and all three
fins on my prop were torn off. I replaced with a spare and after
driving back to Atlanta pulled the prop and spun the shaft and
noticed some runout . The motor is a 2015 merc 4stroke and I
am looking for advice.Repair old shaft if possible or replace with
new. Also the old prop does not get flush with the lower unit.
I am trying to figure out how to load pics but as off yet have not
been able to do so.
Thanks, Super5

What part of the White did you fish? It's been real high lately, just wondered.

I've seen guys straighten shafts before. It takes some time but can be done. It's not pretty to watch 'em do it either. Hammer, vise, press, etc. You've got to take it out to straighten it. Have you priced a new one yet? I've not done a Merc within the last 20 years, but the older ones-the few I messed with-weren't hard to do. 2 bolts, remove the entire gear mechanism, pull shaft out, install the shift clutch, reinstall. Takes about 10 minutes.

Rather than whacking the old shaft with a hammer, I'd check some local machine shops and see what they would charge you. Looks like new shafts ( I have no idea what hp your motor is) run between 200 and 400 bucks.

If you do the removal and replacement, all they do is use some big machine to do the muscle work, I can't imagine that it would cost more than $100.00 or so. ??

richg99

Turbo,
I was hoping you would reply.The White shut off for a
couple of hours around mid morning and around 3 or 4
they would turn it on again.We fished the dam, White Hole,
Wildcat and Cottter. The shoals below Cotter ate my prop and shaft.

Super5,
I hit an oyster reef last November with my 2012 60hp 4 stroke and bent the output shaft. It had about .030" runout at at the last smooth section before the threads for the retaining nut. I called Nettles Props in Austin TX and inquired about that amount of runout. They said it was too much and that it should be below .005".

I had never removed the lower unit from an outboard before so I was a little timid....but I waded into the waters anyhow. It is not hard at all. First remove the lower unit from the engine. You will have to remove the shift shaft before you can proceed with removing the output shaft. The service manual I had did not show the detail about the shift shaft coming out first so I was having problems getting it apart. I called my local Bass Pro and spoke with their head tech and he walked me through the rest of the disassembly. He stated that the older engines would come apart with the shift shaft in place, but the design changed around 2012.

Anyhow, I stripped it completely down and tool the shaft to work and straightened it myself to less than .0005" runout. Way overboard, but I was there and had the time.

Might as well put a new genuine Mercury water pump in while you are there.

The only seal I needed to replace was the water pump gasket. All of the shaft seals were in great shape. I did lube the lip seals good before reassembly to ensure they did not burn out before lube had a chance to get to them.

I do recommend taking a ton of pictures as you go. Especially the relationships of the shift fork dog position. You never know when you will get pulled away from a job and be looking at it in 2 months wondering how to put it back together.

Rob

Should I get a service manual for this motor in order to pull the prop shaft.
2015 merc 25hp 4 stroke long shaft.
Thanks, super5

I was never able to find a free manual to download so I grabbed one for a 2001 model and it got me close enough to get started. From there the Bass Pro tech helped.

First remove the prop, drain the lower unit oil, and remove the lower unit. It should look real close to the photo below.

Remove the white coupler and all the bolts holding the water pump in. Remove the water pump and hardware. Take a photo of how the water pump looks in the sheetmetal housing. If you take that pump out and put it back in backwards you will be in for some hurting.



You can pull the shift rod right out. There are a couple of little widgets that will pull out with it so be ready to take a photo of the order that go back in. You can see them on the blown up view from the manual below.



From there remove the two bolts down where the prop was and remove the bearing housing. I rotated the housing by gently tapping on the bolt hole ears. Gently so as not to crack it. From there I was able to rotate it back and forth and pull it out.

The shift rod drive dog will probably fall out, but you can see in the photo how it goes.



From there remove the large spring like “thingie” and the rest should come apart no problem. Take a ton of pictures.



Rob

super5 said:

Turbo,
I was hoping you would reply.The White shut off for a
couple of hours around mid morning and around 3 or 4
they would turn it on again.We fished the dam, White Hole,
Wildcat and Cottter. The shoals below Cotter ate my prop and shaft.

Click to expand...

Thanks for the update on the river. My girlfriend's folks have some property at Allison; that's usually where we're fishing at but the lake is 30+ feet higher than normal and they've been releasing water like crazy. Thus, we've kind of avoided the river so far this year, but anxious to go back out there. We put in at Allison and run upriver toward Boswell shoal and float back down almost to Round bottom, by then we're usually sun burnt or just plain worn out.

Time for a jet yet? Sure see a lot of them up in those parts; and honestly is probably the only way to go for that river. I've rented them in the past and borrowed one, and loved it but I also fish many other areas that a jet would be useless in, such as a local lake which averages 2 feet deep and is FULL of leaves from all of the cypress trees. Those leaves and grass plug the jet intake almost immediately. Real pain in the back side to have to stop every 10 feet, let the junk fall off, and then restart and go another 10-20 foot. I can't afford 2 boats. One is enough; I'll deal with the White as best I can with what I have.

Ebug thanks for the parts breakdown. I haven't messed with a merc since the early 1990's, or thereabouts, so seeing that breakdown is a reminder. They weren't real hard to get apart but had to have some know-how and a tool or two. Makes me appreciate working with the Yamaha's. A lot simpler at least in the foot of the 15, 20, 25, and 30/40hp motors.

i slammed a rock with mine a few years ago on my merc. bent the shaft bad. i just went ahead and ordered the tohatsu shaft which was 1/2 the price of the mercury shaft. wasnt too hard to do. the hardest part was waiting on the parts to show up.