Random slamming out/in gear when going forward

[Stinkytoots]

I have a 1979 Evinrude 85hp Model 85999r. When I am shifting into forward or reverse the unit seems to slam into gear more so than normal, and randomly when moving forward slow or fast it seems that it will shift out and back into gear. What should I look into 1st?

Thanks!

?I like nonsense, it wakes up the brain cells. Fantasy is a necessary ingredient in living.?
Dr. Seuss

 

[Scurvy Knave]

Re: Random slamming out/in gear when going forward

sounds like rounded/worn clutch dogs. You will likely have to open the gearcase and inspect.

 

[Stinkytoots]

Re: Random slamming out/in gear when going forward

That's what I was thinking too, I had just told my wife that tonight as we were taking the boat out and did some fishing. I guess I will have a good winter project this year.

Thank you!

 

[Stinkytoots]

Re: Random slamming out/in gear when going forward

ok, I finally was able to take the time to disassemble the lower unit and inspect the gears and clutch dog. I took a video of the gears and posted them on youtube in hopes that someone can look at them and tell me if I need to replace the forward and reverse gears. There is some wear on them, but nothing like I was expecting, it seems minor to me and they are not rounded to a point of replacement. So please watch the short video and tell me if there is something that I am missing or if there is something else that I should be looking into.

Video at: Evinrude 85999R lower unit gears question - YouTube

I have also inspected the drive and prop shafts and there isn't any major wear on those either. When I did disassemble the lower unit I was expecting to see many metal shaving/chips, but there wasn't any big chunks. They were just the standard fine sand feeling in the oil with a few chips stuck to the magnet of the drain plug.

 

[multimech]

Re: Random slamming out/in gear when going forward

Can't really tell from your video about the wear on the clutch and the gears. One thing to check is the shift rod height, make sure it is set correctly. If it is and the lower unit still jumps in and out of gear at different speeds, it is definitely your gears and or clutch dog. There is no other explanation for it.

You wouldn't find chunks with that kind of problem. If the oil feels like fine sand, you have too much metal for normal wear and I would go for the dog and or the gears.

 

[Stinkytoots]

Re: Random slamming out/in gear when going forward

So I got everything apart and the only thing that seemed to be an issue was that the cluch dog had some minor scratches on it compared to the new one. Since I bought it I replaced it anyway and am putting everything together. I noticed that when the drive shaft is loose but screwed to the pinion that it almost or does touch the clutch dog. Is that normal? Will it correct when I put the drive shaft plate and water pump back together? Or is there something that I need to be adjusted to correct this. Thanks!

 

[multimech]

Re: Random slamming out/in gear when going forward

That is completely normal for the small clearance. Scratches are not an issue with the clutch dog. Look at the "dogs" themselves, are the rounded? Are the gear dogs rounded? That is what you would be looking for, as well as a lot of minute shavings in the gear oil.

Not really sure about your engine (I don't work on anything older than 20 years old. Saltwater you know) have you checked what the shift height should be, if it is at all adjustable. If it is the wrong height you would have an issue with shifting and engagement.

 

[Stinkytoots]

Re: Random slamming out/in gear when going forward

Not really sure about your engine (I don't work on anything older than 20 years old. Saltwater you know) have you checked what the shift height should be, if it is at all adjustable. If it is the wrong height you would have an issue with shifting and engagement.

I am glad to hear that. I am pretty sure that is what the problem was this whole time. The shift rod is adjustable and should be at 26 27/32, The oil did have some grit to it but overall wasn't that bad. The dogs are not rounded, it was like the dogs were just barely catching the gears. I replaced the clutch dog, cables, and all the seals since I had it apart and once I get the correct height set I should be in business. But Since I was working it, I also did complete carb kits and cleaned up the engine. Next weekend all should be done and ready to try in the water. getting excited

 

[Stinkytoots]

Re: Random slamming out/in gear when going forward

I have the boat completely reassembled now and I am wanting to verify that the control cables are set correctly.

For the shifter cable, I put the controller in neutral and the gears in neutral, I then adjusted the cable to gently slide onto the holding screw and tightened.

For the engine adjustment cable, I placed the controller in neutral and adjusted the cable so that the idle screw was touching the engine.

please let me know if I did this correctly, I cannot find any information on it in my service manual.

Thanks

 

[Stinkytoots]

Re: Random slamming out/in gear when going forward

Anyone?