Bent prop shaft, Evinrude 70hp 1986

[acarter92]

I noticed tonight after installing a new prop on my motor that my shaft is bent, I'm thinking about 1/16" movenment at the trailing edge. I'll put the micrometer on it tomarrow evening and get an exact number.

About a month ago I hit a rock on the river (at idle speed) that stalled the motor and bend my prop. I bent it back and didn't get around to ordering a new one untill last week. Since I bent it I've probably drove the boat around 200-300 miles. I checked the lower unit oil tonight and there is no water.

I did some reading on the topic and it sounds like a pretty tough job, I'm pretty good mechanically, but have very little experience with marine engines. It also sound like it can get pricey if I take it to a shop. I'm sure I'll get yelled at but, what if I let it go? I don't own the boat that long and for all I know it's been that way for years, tonight was the first I looked at it and the prop was rough before I hit the rock. I don't notice it while driving, but I may be used to it. The boat get used almost every weekend and runs about 50-100 miles each weekend.

It looks like there are quite a few lower units on eby for under $500, but I'm guessing they are going to have their own problems. If I have to spend the money and time I will, but I'll probably upgrade next year anyways.


Just looking for opinions, advice, etc...

Thanks,
Austin

 

[boobie]

Re: Bent prop shaft, Evinrude 70hp 1986

Should have no more than .005-.010 out of round. If you want to do this yourself, get an OEM Factory Service Manual. NOT Seloc or Clymer. I would not run it the way it is or more can go wrong in the g/c.

 

[acarter92]

Re: Bent prop shaft, Evinrude 70hp 1986

Ok, I'm thinking of picking up another lower unit on ebay and just swapping them out. Then I'll fix my old one over the winter and have a spare. How likely am I to get one with another problem if I buy a used one? I see alot on ebay that look like they've been sitting around for 10+ years without a motor (I'll avoid them).

Thanks,
Austin

 

[seahorse5]

Re: Bent prop shaft, Evinrude 70hp 1986

factory spec for shaft wobble is 0.002" measured just aft of the thrust washer taper

 

[boobie]

Re: Bent prop shaft, Evinrude 70hp 1986

I was talking about the End of the prop shaft.

 

[acarter92]

Re: Bent prop shaft, Evinrude 70hp 1986

Called the local marine shop that I deal with from time to time. If I drop off the lower unit they can take out the shaft and straighten it for around $150 labor. For that price, it's not worth my time to try to do it. I'll probably have them replace the bearings and seals while they are in there.

Austin

 

[boobie]

Re: Bent prop shaft, Evinrude 70hp 1986

Wise choice...........

 

[acarter92]

Re: Bent prop shaft, Evinrude 70hp 1986

Well, it turns out that $150 was too good to be true... They called me today and said "It's going to take a little longer that we estimated, it turns out that we have to take apart the whole lower unit to get the shaft out to straighten". I'm thinking No ****, I knew that from 10min of googling. They estimate it'll take them about $500-$600 worth of labor to get it fixed (they've already got $100 into it). Maybe they though it would just unbolt in 10 minutes? I thought this was a pretty common engine and the way he talked they fix bent shafts all the time (apparently not).

To top it off I dropped it off last wednesday, he said it should be done by the weekend (last weekend). I didn't get a call untill today (didn't bug them), and now if I say go ahead it might be done by the middle of next week (they dont' even have to order parts). Two weekends lost, there won't be another...

Anyways, now that I'm done venting. I told them to hold off and I'll come and get it, I'm going to give them a little grief about that $100 too (not sure what they did for an hour +). I decided I'm going to do it myself. How hard can it be? I've rebuilt a dozen or so engines (top and bottom end).. I figure I'll get it out and take it to my buddy's machine shop to have them straighten it.

So what am I going to need? What brand book should I get, I've done all my regular maintenance on this motor without one, but I figure I'll need one for this job. So what brand is better/ best? I figure I'll order all new seals (they are cheap) and probably go ahead and get new bearings. What special tools will I need, I figure I need a puller, I have a few regular styles for car and Motorcycle engines, will this require a special one? I've read some stuff about shimming the shaft, does this require a tool, I have feeler guages, and do I need a selection of shims while putting back together? I'm sure I'll have more questions, but this should get me started.

I'd like to order as much as I can at once (with the manual) to try to limit shipping costs.

Thanks,
Austin

 

[orbanp]

Re: Bent prop shaft, Evinrude 70hp 1986

These guys are not really straight shooters! They still say that the shaft has to come out. That is what they told you in the first place.
What is the hourly labor rate? 90 dollars? That is generous. Then it is 6 to 7 hours of labor! Seems a bit too much! Perhaps others can say what is the factory norm for diassembling/reassembling the lower unit.

Peter

 

[acarter92]

Re: Bent prop shaft, Evinrude 70hp 1986

These guys are not really straight shooters! They still say that the shaft has to come out. That is what they told you in the first place.
What is the hourly labor rate? 90 dollars? That is generous. Then it is 6 to 7 hours of labor! Seems a bit too much! Perhaps others can say what is the factory norm for diassembling/reassembling the lower unit.

Peter

I think their rate is something like $80 or $85 which I believe is about average for this area. What I don't get is that they said it would take them $150 worth to pull it, straighten it, and put it back together. I thought that was low and I wouldn't have complained if it came in significantly higher, but I don't get why they had to start taking it apart before they realized it would take more than 3 times longer than they estimated. It seems like a job that wouldn't change much from motor to motor and therefore should be an easy estimate. They didn't even have to remove it from the boat, I brought the lower unit it already disconnected from the motor.

It makes me wonder if they would have even done it right to begin with, when I talked to them when I dropped it off he didn't even want to replace the seals. It seems to me that if your going to put all that labor into taking it apart, what another few bucks for seals?

Austin

 

[acarter92]

Re: Bent prop shaft, Evinrude 70hp 1986

Well, I picked it up Saturday. To make a long story short they told me that the $150 was only to straighten the shaft once they removed it and the labor wasn't included, very misleading and never said a thing about that untill saturday when I started asking questions.

Anyways, They had it taken apart down to the shift clutch (didn't know that took two hours). I finished removing it tonight, pulled the drivesahft and shift rod and it came right out. So I've got the shaft out and am trying to decide whether to replace it or take it somewhere to get straightened. Anybody have a luck with having a machine shop do it? I did find one on ebay for $50 that looks pretty good.

Aside from that I have a pretty rough looking pinion gear (pic below). It has one pretty bad tooth, the rest are 100%. The foreward and reverse gears are 100%. I am assuming this happened when I hit the rock (sheared the tooth?), I'm just curious why it didn't hurt the foreward gear. The shavings from the tooth worked their way up to the thrust bearing on the drive shaft and started to wreck that, so I have to replace that also. I'm glad I didn't let it go any longer or I think I would have had major problems. So what do you guys think of the pinion gear, definately replace? I'm thinking so, but if I can't find a used one (didn't look on ebay yet) it's $300+ for the OEM set.

I'm also replacing all the seals and O-rings, except the ones I did in the spring (for the water pump housing). For the little bit of extra cost it's worth the piece of mind to me.

Sorry for the poor quality pic, I was using my phone (didn't want to get the camera dirty)


Thanks,
Austin

 

[orbanp]

Re: Bent prop shaft, Evinrude 70hp 1986

Yes, I would replace the pinion gear. If not, it will shed further pieces of it, and it will ruin other good parts of the gear case.
Two hours of straightening a shaft? That is really excessive!

Peter

 

[acarter92]

Re: Bent prop shaft, Evinrude 70hp 1986

Yes, I would replace the pinion gear. If not, it will shed further pieces of it, and it will ruin other good parts of the gear case.
Two hours of straightening a shaft? That is really excessive!

Peter

Ok, that's what I thought. If I can't find a used one I'll bit the bullet and buy it new.

$150 to straighten the shaft was high I thought, but the part that ticks me off is that they failed to mention that the $150 didn't include the labor to remove or re-install the shaft (which is most of the job). When I picked it up he told me I should have known that. Whatever....

Austin

 

[jimmbo]

Re: Bent prop shaft, Evinrude 70hp 1986

If the pinion is damaged, what about the forward and reverse gears? It looks like 3 of the teeth have varying amounts of damage. I'll gamble and say that these were the teeth in contact with the forward gear when you hit the rock.

 

[boobie]

Re: Bent prop shaft, Evinrude 70hp 1986

Hate to tell you this but the pinion and forward gear come as a set. After that the drive shaft will have to be shimed with the proper tools.

 

[acarter92]

Re: Bent prop shaft, Evinrude 70hp 1986

Hate to tell you this but the pinion and forward gear come as a set. After that the drive shaft will have to be shimed with the proper tools.

Yes, they come as a set and are $300+, but I found a single pinion gear on ebay for $80 and a few other places online for around $100. Is it alright to only replace the pinion gear. I closely examined the foreward and reverse gears and they are 100%. No damage.

After doing some reading I beleive I need this tool, right? http://www.iboats.com/Shimming-Tool...OMC-Sterndrive-Cobra-Sierra/dm/view_id.203960

$360 :facepalm:, I'm sure if I found a "good" shop they could do it for me for a small fee, but I don't know of any near me. If I was reading right, this shimming is done before the shaft is installed and the shims go below the bearing housing in between the thrust washer?

Anyone know of a shop that can do this somewhere around Schuylkill Haven, PA?

Thanks,
Austin

 

[Jim311]

Re: Bent prop shaft, Evinrude 70hp 1986

I would have thought that straightening a prop shaft that is probably made of some sort of hardened metal would be a half azz fix at best. I'm not sure I wouldn't just buy a lower unit in good shape for 500 bucks.

 

[boobie]

Re: Bent prop shaft, Evinrude 70hp 1986

A good machine shop can straighten a prop shaft, but it's the pinion gear that's the issue here.

 

[acarter92]

Re: Bent prop shaft, Evinrude 70hp 1986

Talked to a "real" mechanic today. So I can't just get a pinion gear, they will not mesh properly he said (which makes sense). He said if I found a set it would probably take 1-2 hours to shim it properly, he said it has to be done with the whole lower unit.

So, instead of putting $500+ into mine and waiting for parts and service I'm just going to look for another lower unit. Hopefully it wont' be worse than mine.

Austin

 

[orbanp]

Re: Bent prop shaft, Evinrude 70hp 1986

Talked to a "real" mechanic today. So I can't just get a pinion gear, they will not mesh properly he said (which makes sense). He said if I found a set it would probably take 1-2 hours to shim it properly, he said it has to be done with the whole lower unit.
...
Austin

Theoretically he is right. That is the way to do it correctly...
However, if you find that a replacement gear case turns out too expensive, or a complete gear set is also too expensive, I would not hesitate to replace just the pinion gear. If that replacement pinion gear was also made by OMC, chances are that it will work fine (it could be a bit noisier and have a bit less efficiency). These gears are not made to such loose tolerances. When you shim it, you could check the meshing by looking at the contact area pattern by painting one of the gears with some marker.

Peter