changing shift cabler in 1981 OMC 400 stringer

[ybcoach]

Re: changing shift cabler in 1981 OMC 400 stringer

One small reply on your paint and bolts issue.
You cannot heat the paint off like any regular paint does. The gearcases are sandcast or diecast aluminium . So they where painted especially for these alloys. You can get a suitable primer and paint from your local marine store . The old OMC color is still available. In order to get a good lasting paintjob done, you MUST clean the gearcase very carefully. All the parts that where unprotected will carry a thin layer of oxidized aluminium. (White powder stuff when it comes off) This will come off after painted. The same stuff is seizing the bolts into the case. When you get the bolts out , and assemble the drive with new ones, clean the thread holes very carefully and put a layer of blue-silicone-form-a-gasket on the bolts. This will maintain a small layer between the hole and the bolt. When you maintain your drive again (after a few years) the bolts will come out easy.
I used to have this old evinrude 85Hp 2-stroke outboard that had seized-up every bolt on it. After doing the job as discribed, 5 years later i had to re-seal the gearcase + waterpump. All the bolts came out is they where put in........
Good luck with your drive!!

 

[CptTrevor]

Re: changing shift cabler in 1981 OMC 400 stringer

Again thank you very much. I sent you a message. Let me see if I understand you correctly what you are saying I don't have to strip the old paint off just clean the dirt and grease off and prime and repaint is this what you are telling me? I also would like to know if the 120/140 hp OMC stringers outdrives were the same .I can get some parts from a 120 OMC but I have the 140. These parts are off an electric shift no good for me. Have to keep on looking. Cpttrevor

 

[ybcoach]

Re: changing shift cabler in 1981 OMC 400 stringer

correct, just clean and paint.... The 120 and 140 are the same outdrives. OMC made 2 drives: 400 and 800.
400 is used on 120 and 140 Hp , the 800 with the larger engines. From '81 on they did not langer call them 400 or 800 but used the Horsepower as unit number. They also changed from Hydro assist shift to pure mechanical assist (as in the outboards). As for parts, U can even use a 800 gearcase , but change the prop to compete with different gears . I can tell a lot about them , but i think this is off-topic

 

[CptTrevor]

Re: changing shift cabler in 1981 OMC 400 stringer

I have the housing bolts off but am having a hard time getting it to dislodge. When it dislodge it just comes off when I pull on the short cable and that is it. How about when I am ready to install the new cable do I have to do any special adjustment to anything ? This is the first time I am working on a boat and I am enjoying the experience thanks to you for all you expert advice. Is it possible to convert a hydromechanical shift system to a mechanical shift-if it is possible is it very complicated. Cpttrevor

 

[ybcoach]

Re: changing shift cabler in 1981 OMC 400 stringer

sorry about the delay, i was out for the weekend. When you pulled the short cable , and the housing lifts up, you should be able to lift the whole housing off the rack that is visible now. It's rare when it should not come off. Nothing is sticky there. When it's off, you have the housing and the cable as one unit. First when changing the cable, lift the small cover (4 small screws) Then you'll see the two pulleys . The cable wires run in a particular way over and under the pulleys. This is very important: make a drawing if you don't have the manual. Maybe it's better that i scan the pages from my manual and send them by PM? I have some pictures too from my rebuild. I'll try to put them on picasa. Also a picture from the tool i made to pull the rack-pulley off the shifter housing.
To answer your question about converting to full mechanical shift/: Yes it is, but you'll have some serious issues to deal with. You'll need new gears, a forward gear housing+shifter , a new shifter rack, a new prop-shaft and so on. The only thing left are the housing parts really. Once it's rebuild, the way the thing shifts, is reversed. It means that when you put your boat in forward, it will go reverse. The shifter and clutch engagement is just opposite. If you know can find a inverted shifter cable for the remote control, go ahead.
My advise to you is: if your gears look fine, if the bearing in the oilpump is in good shape and the shifter system looks in good shape, continue with this gearcase as is. Many problems with this hydraulic shift assist is caused by water intrusion or shifting at high RPM. You have to handle the controls as it is a beautiful lady: gentle and smoothly. Check your gearcase oil every time you get the boat out of the water. So keep those nylon seals in reach. After a weekend on the lake , having some drops of water is not a drama, but drain it and keep track of the amount. When it's exessive, re-seal the gearcase .

 

[ybcoach]

Re: changing shift cabler in 1981 OMC 400 stringer

i'll think i can make some scans from my manual and Pm to you. Without the service manual , you are a sitting duck.......

 

[CptTrevor]

Re: changing shift cabler in 1981 OMC 400 stringer

Did you send me the scans? I am still trying to find a shift cable I would like to know if you have any ideas about changing this system over to the Mercury system of Alpha one outdrive Cpttrevor

 

[CptTrevor]

Re: changing shift cabler in 1981 OMC 400 stringer

my friend I dont know what happened to you I hope you are ok I was sick for a while I am ok again Cpttrevor