Shift Dogs slipping on '77 Johnson 25 HP

[Tom Ireland]

While under way, the shifter will slide backward and kick out of gear. If I hold the shifter forward and throttle up, it will slip momentarily every few seconds. It sounds like the shift dogs are worn to me. Can the average Joe with pretty fair tools tackle this replacement or are specific tools needed to pull gears, etc. And if it is a project that can be done under the shade tree, can the appropriate parts be acquired for a motor of this vintage? Where?

 

[plywoody]

Re: Shift Dogs slipping on '77 Johnson 25 HP

Get a service manual for it.<br />That I believe is one of those split gearcases, and relatively easy to work on.<br />Parts are available, either on-line, and perhaps thru your dealer.<br />Sounds to me like your assessment of your problem is precisely correct.<br />Work patiently, and follow the manual's instructions, and you should have no problems.<br /><br />Good Luck,<br /><br />John

 

[DJ]

Re: Shift Dogs slipping on '77 Johnson 25 HP

Tenn,<br /><br />Not sure if your '77' has a split gearcase or not. If so, it's simple. If not, the L/U guts come out from the propeller area. Some special pullers may be needed.<br /><br />Your assesment is correct on the problem.<br /><br />A manual is a must. The Clymers or Seloc would be sufficient-for that job.

 

[plywoody]

Re: Shift Dogs slipping on '77 Johnson 25 HP

My 82 Johnson 25 had a split gearcase. All of the other models in that year had thru the hub exhaust except for the 25, for some reason.<br />All I know it was a heck of a good engine before I finally sold it, and it is probably still at work somewhere in Alaska now.<br /><br />John

 

[Bear]

Re: Shift Dogs slipping on '77 Johnson 25 HP

If you don't have the split gearcase it might look like this: just the picture <br /><br />The whole page: Johnson Evinrude Gearcase 20-35HP 1985-1997 Parts Guide <br />

 

[Schep]

Re: Shift Dogs slipping on '77 Johnson 25 HP

Tenn Vol ....ok here goes, i had the same problem with my 76 evinrude, 25hp. it has a split gear case and you can drop everything out in a few minutes. drain the case, remove the bolts holding the lower case together.on mine remove the pin fastening that holds the shifter yoke and remove the prop.(makes it easier to handle) drop the lower half, slip the yoke off the shaft and the whole unit comes out into your hand. now here's the trick, i had the same problem, but there's a hidden bolt securing the shifter shaft inside the exhaust tube. try and move the shaft once its off the l/u, the shift handle on the side should move, if not the connections are loose. if there tight look at the clutch dogs and see what they look like, you can still get parts no problem at a marine store, for a money saving tip, on my evinrude, you can slip off the forward clutch and swap it with the reverse clutch dogs, they are the same and you'll have better if not new dogs for your forward gears. good luck

 

[Joe Reeves]

Re: Shift Dogs slipping on '77 Johnson 25 HP

Tom..... That engine does indeed have a split gearcase and can be worked on without any special tools, however, I would suggest strongly that you obtain a service manual.<br /><br />If it has been jumping out of gear bad as you state, I'd assume that the lobes on both the shifter dog and the forward gear are worn. I do not have either in stock but I'll list the OMC original and superceeded part numbers and the approximate prices below for your convenience. You may use any of the numbers if you can locate them.<br /><br />Shifter dog - 316501=390030 - $75.00<br /><br />Forward Gear - 389236=391085=390972 - $240.00<br /><br />Hopefully you can locate a good used gear if needed.

 

[P.V.]

Re: Shift Dogs slipping on '77 Johnson 25 HP

Once you get the gears and cluth dog out you will note that they have two "dogs" that engage each other. If you check with your friendly OMC (BOMB) dealer, he can look up an old sevice bulletin and you can purchase the "severe service three dog" gear set. This is a better set-up as the loads are spred and the forward bronze bushing is replaced by a needle bearing assembly. Much better way to go !!!!All the later units went to the more heavy duty "3 dog" gears !!!

 

[plywoody]

Re: Shift Dogs slipping on '77 Johnson 25 HP

If it were me, on a 1972 engine, I would find whichever set was cheaper, or even a used set that looked to be in good shape.<br /><br />As it is, you got 30 years of use from the set you had, and I would not spend a whole bunch more dollars to improve that on a 30 year old engine. If you are careful, and make sure you shift into gear firmly and quickly, and not allow the gears to "grind" before engaging, you should get all the life you might need out of a standard set. Or even a used set in good shape.<br /><br />John