• If this is your first visit to the iboats.com Boating Forums, be sure to check out the FAQ. To post a question or comment, begin by signing up. To start viewing messages, select the forum that you want to visit from the selection below.


Announcement Module

Help Tip: If you have a question that has not been answered to your satisfaction in the archives, it is always best to start a new thread of your own. By starting your own thread, you will receive the maximum number of views by forum members.

Below are some additional forum policies in hopes of all iboats members will follow, Thank you.

1. Please do not reply to old topics or hijack existing topics. Old topics of a technical nature are like a library book, Please do not write in them.

2. Old topics should be considered archives and used for reference only. Please do not reply to them.

3. Do not take over someone elseís topic (aka hijack) with your own question, even if it is similar. If you have a question that has not been covered to your satisfaction in the archives, it is always best to start a new topic of your own.

4. If you have a question for the original poster (OP) and the topic is over 30 days old, send the OP a PM, he may not even visit the forums any longer, or may not notice your question in the old topic.

5. By starting your own topic, you will receive the maximum number of views by forum helpers that may not even notice your question when itís posted at the end of someone elseís topic. And those answers will be specific to your particular issue.

6. Please do not post to topics that have been inactive for more than 3 months unless you are the original poster. We have very active forums and any topic that remains inactive for that long should be considered "dead". It is especially confusing when there is an entirely new question posted to an old topic.

7. Posting at the end of any topic is considered to be hijacking the original posters topic which in turn subjects the topic to be closed if it continues to happen thus not making it fair to the original poster in the future had for some reason he/she needed to return for additional information or provide an update of the problem solved which is always welcomed within a reasonable amount of time frame.

8. Please note that you should see a red banner pop up near the bottom of each inactive topic asking you not to reply to old topics. The Red banner will read: Please note this topic has been inactive for 90 days. For the best results, please start a new topic.

Thank you all in advance for doing your part in helping iboats run a smooth ship.

Additional forum rules linked below.
See more
See less

cracked gearcase

Page Title Module
Move Remove Collapse
Conversation Detail Module
  • Filter
  • Time
  • Show
Clear All
new posts

  • cracked gearcase

    I'm trying to help out a disabled friend who can't afford a new motor. The motor is an Evinrude, 70hp outboard. Model# 70573E. Serial# J0007174. Fits a pontoon boat. The gearcase is cracked from winter freezing, with the crack running a bit over halfway around the cone-shaped area at the front of the gearcase. Total crack length is about 5". Can something like this be brazed, welded, epoxied, etc? Is this worth trying?ThanksRick

  • #2
    Re: cracked gearcase

    It can be welded but it must be very clean and probably left to a machine\welding shop cause the heat can cause it to warp out of round if not welded right, but definately doable, and cheaper than a new engine for sure


    • #3
      Re: cracked gearcase

      Thanks for the quick reply. Hopefully there's a good welder around here. I'm not a boat mechanic but do have an automotive background. Am I correct in assuming this gearcase is similar in setup to an automotive differential? I'm hoping that I'm not getting in over my head with this.Rick


      • #4
        Re: cracked gearcase

        Hello Rick, DO yourself a favor and get a Seloc Manual, very easy to understand and it will tell you step by step details and required specialty tools to do the job, I had never worked on a boat motor till last saturday and I disassemble my lower unit all the way down, now for the trick , can he put it back together? Good Luck with your project. CW


        • #5
          Re: cracked gearcase

          even better than a Seloc (or Clymers etc...) is a factroy manual for that particular engine. There are several places that sell them including I-Boats, Ken Cook....They aren't hard to pull apart and rebuild but You need to be sure that is done properly.As for the gear case crack, Like Denis said, get a machine shop or some where that specializes is welding/fabricating aluminium to weld that up for your friend. If that isn't possible, try looking around an outboard wrecker for another lower unit that you can swap over.Good luck and keep us posted.P.S. WELCOME ABOARD!


          • #6
            Re: cracked gearcase

            Thanks, all of you. I very much appreciate it. I've never torn one of these down before so I'm assuming that it's somewhat similar to an automotive differential ring and pinion. I'm a long way from any large marine shops or similar. The nearest place to even get an outboard this size is 75 miles from here so I'll have to check around for a good welder. If I'm looking at that model number right, this motor is from 1973? I'm not sure if this could be a related problem, so I'll ask. Last year, July, she asked me to come over because her boat wouldn't start. What she described sounded like a dead battery or bad connection. What I found was a motor that wouldn't rotate past a certain point. I removed the spark plugs to make it easier to turn by hand and started manually turning it back and forth, managing to get it to turn a little more each time. It felt like there was a soft obstruction in the motor, like a rotton piece of wood. The lake she's on is full of that kind of stuff. Since I'm not familiar with how outboards are set up, I'm assuming it sucked a piece of this debris into the pump, and manually cranking the engine eventually chewed thru it. Am I correct in guessing that this pump is also in the gearcase or do I need to go farther up into the motor to check on this? I appreciate the help and all the patience. If any of you make it over to the computer support forums I work at, I try to return the favor. Thanks.Rick


            • #7
              Re: cracked gearcase

              The pump ia a little higher in the gear case, and is made of ruber so if it did chew in a piece of wood, it might need attention, its pretty close to a ring and piunion except that the pinion has 2 gears on it 1 on either side, so the motor always turns the same way, and the gear that is selected (locked) determines forward or reverse


              • #8
                Re: cracked gearcase

                Ok, we'll assume that the pumps impeller is no good now, you said you rocked it back and forth. That is a bad thing for these water pumps. The motor should only be turned clockwise. Luckily, you can replace this while the lower unit is off being repaired.The motor was built in 1975, not 73. And you will need to get the manual. If purchaseing one is too hard, try your local library.As a last resort, you can check the evinrude website, or ishopmarine.com for exploded diagrams of the engine. They are seperated into sections, try this link and you will see the one you need first. http://www.ishopmarine.com/ishop/jsp...11547~C0143566 Good luck.