1967 Evinrude 80 HP (Gearcase troubles).

[kjones734]

I currently own an 1967 evinrude (model #80753) it is an speedifour motor (Manual shift) that runs good but I am having problems with the gears (I think).

Here is the issue, when I have the motor in forward gear at idle it will go fine but when I give it some power it will make a clunk noise and lose power for a split second, this clunk is very rhythmic and comes around about every 4-5 seconds. and now if I give it any power when it is is gear it will jump out of gear completely and rev out of control until I shut the engine off. Then after the last time I took the boat out and this happened it leaked a large pool of thick grease on the ground beneath the engine it was yellowish-green in color. do you know what this is from?

Now I have been researching on the web for a little bit and come up with "you are jumping out of gear. The lugs on the fwd gear are worn. A new clutch dog will not correct this. You need a gearset and now another new clutch dog. Been there, done that. It's the only way to correct the issue."

I would like someone to confirm this before I start doing any work to the engine. I also looked up the forward gear (part # 377870) and it is pricey (+$100). I have heard that it is possible to swap the forward and reverse gears, is this possible? When it says lugs is he talking about the washers behind the gears? I do not see the word lug in the parts diagram.

Finally what is all involved in doing this work my self? Can I just take the lower end apart and replace the parts (I have the manual) rather easily? Will I need to replace any other parts such as seals or gaskets?

Thank you so much for any and all help you can provide, I really want to get my boat working again so I can do some fishing this year.

 

[yorab]

Re: 1967 Evinrude 80 HP (Gearcase troubles).

kjones, there are numerous threads on this forum that describe the clunking/jumping out of gear problem. Joe Reeves has explained this very well on a few occasions. Search the forums a bit. And yes, you will need to replace seals and gaskets when you get in there. There are lower unit seal kits available right here on iboats.

 

[kjones734]

Re: 1967 Evinrude 80 HP (Gearcase troubles).

Thank you for the reply, Is it possible for you to post a few of those links? I tried searching and was unable to find them.

 

[dew2]

Re: 1967 Evinrude 80 HP (Gearcase troubles).

The clunking every few seconds sounds as though a bushing is bad,The jumping out of gear is normally the gear and clutchdog they have ears that protrude and when shifted lock together.You need to open it up get a manual and see what is bad
the dog and gear or bushings

 

[yorab]

Re: 1967 Evinrude 80 HP (Gearcase troubles).

Here's a link: http://forums.iboats.com/showthread.php?t=460562&highlight=clutch+dog

You can learn a bit from it and use some of the key words to search for other links. If I get time later, I'll look for that post that describes how the clutch dog gets worn down over time and what needs to be done to correct it. I read that thread a few weeks ago.

 

[yorab]

Re: 1967 Evinrude 80 HP (Gearcase troubles).

Here's another link:

http://forums.iboats.com/showthread.php?t=459451&highlight=reeves

If it turns out that you need gearbox parts, you probably won't find them on iboats. I have a gearbox from a 1961 Speedifour that I could part out for a price that would make you smile. This assumes that the part numbers are the same. But first, be sure of what it is that needs to be adjusted/replaced. There is no buying/selling allowed on the forums so if you want to discuss this further, PM me.

 

[kjones734]

Re: 1967 Evinrude 80 HP (Gearcase troubles).

Thank you very much for the helpful replies, I will call my brother over and we will take it apart and have a look. Is there anything I should watch for as I take it apart? Also does any one have any ideas about the thick grease that leaked out?

 

[kjones734]

Re: 1967 Evinrude 80 HP (Gearcase troubles).

well I took it apart today and I confirmed the problem is the dog is hella worn down and the gear has taked some damage where the dog meets. Can I swap the foward and reverse gears with out problems?

 

[F_R]

Re: 1967 Evinrude 80 HP (Gearcase troubles).

You can, but are you sure the reverse is good? It takes surprisingly little wear to make it jump. Worse, a worn gear will destroy a new dog in short order. Then you will be right back to where you are now, but with less money in your pocket.

Not to even mention, you won't have a reliable reverse.

 

[dew2]

Re: 1967 Evinrude 80 HP (Gearcase troubles).

If he can swap out the gears R to F and F to R why cant he turn the dog around??

 

[F_R]

Re: 1967 Evinrude 80 HP (Gearcase troubles).

Well of course he can. But how can we assume the reverse isn't worn? Has he never used reverse?

 

[kjones734]

Re: 1967 Evinrude 80 HP (Gearcase troubles).

The forward gear and the forward dog was beat up pretty bad, but the reverse was in good shape. But i will not be swapping them around I found a new in box forward gear for $75 shipped on ebay. I also picked up a new dog ($25) new lower seal kit ($20) and a new impeller kit ($24). So for a boat it was a cheap fix. Thank you all for your help.

 

[kjones734]

Re: 1967 Evinrude 80 HP (Gearcase troubles).

Just a quick question, What kind of oil do I use for the gearcase? Do I just use standard 80 weight gear oil? thanks.

 

[5150abf]

Re: 1967 Evinrude 80 HP (Gearcase troubles).

LOWER UNIT OIL, just looking at it you cna't tell the difference from 80/90 but it has addatives to deal with water intrusion.

You can get it at any Wal Mart and most auto parts stores.

I normally get 2 and fill one completely up, it is easier to get the lower full.