'59 Evenrude Big Twin 35hp pops out of gear

[ORnewBoater]

Hello all,

I have and old 1959 (I think) Evenrude Big Twin 35hp. I just got it running nicely and I have a new problem. At high rev after a few minutes it seems to pop out of gear or something having that kind of effect. Once I bring the throttle down there is a small thud as it re-engages. I checked the sheer pin and that is not the problem. I am thinking of pulling the bottom off and apart to inspect the gears. Before I do I thought I'd ask if anyone has an idea or suggestion.

I also have noticed a crack starting just below the exhaust port. I was wondering if that can be welded (heli arc) or should I look for a replacement. I really like this motor since it goes with the year of the boat ('58 17' Uniflight)

Thanks for your time.

 

[horsefly38425]

Re: '59 Evenrude Big Twin 35hp pops out of gear

I had one of these TUFF old motors. If the Lower has a crack in it it's let'n the down shaft move to the side/ hard to fix. That may be why it jump's out/ I put a heavy spring on mine to help it stay in forward. Let us know

 

[F_R]

Re: '59 Evenrude Big Twin 35hp pops out of gear

I had one of these TUFF old motors. If the Lower has a crack in it it's let'n the down shaft move to the side/ hard to fix. That may be why it jump's out/ I put a heavy spring on mine to help it stay in forward. Let us know

The jumping out of gear is caused by a worn out clutch dog and often a worn forward gear as well. Every time it jumps it increases the wear. It also is death on the shift linkage. It pays to fix it before it gets worse. BTW, holding it with that spring is going to result in death to the shift linkage too.

ORnewboater, are you speaking of a crack at the exhaust relief on the rear of the midsection housing? If so, it probably isn't a 1959 but a 1957 or 1958. Anyhoo, that was a fairly common problem. They reinforced the area on newer models. You might get away with welding it, but it probably is so full of grease & oil from the exhaust that welding won't be easy.

 

[ORnewBoater]

Re: '59 Evenrude Big Twin 35hp pops out of gear

Ok, I went ahead and welded the crack. The mid-section is solid again however the gear problem persists. I am going to drop the lower and inspect the gears, dogs, linkage, ect. Any idea where to get replacement parts? I am guessing the local marina is not going to be much help due to the year.

Thanks for the replies.

 

[1946Zephyr]

Re: '59 Evenrude Big Twin 35hp pops out of gear

I would check for any slop in your shift linkage first. Worn clutch dogs are the most typical suggestions people will give you here, but is not often the case. If your motor has good oil in it and no sign of leaking water in, then it's less likely the case. I just rebuilt one of these a couple weeks ago and the clutch dog was not the culprit. The first thing I would do, is disconnect the shift coupler and drop the lower unit. Once the lower unit is off, place your finger tip on the upper shift rod portion that you see in the access hole and check for up and down play. There should be no up and down play on the upper shift rod whatsoever. If you do find up and down play, then the connection at the bellcrank is loose and needs to be tightened up. If this is allowed to run loose and you spend a million dollars rebuilding your lower unit, your problem will still persist. In order to tighten the connection at the bellcrank, you will need to pull the powerhead.
Once you get all the linkages tightened up, then re-install your lower unit and then check your shift linkage adjustment. On the shifter, you will find two clamping screws. By the way, these motors that have these, have them because over time, you need to make adjustments to them....kinda like having to adjust the clutch in your car or brake shoes. The clutch dog is actually the last place to check and it seems everyone here would make you believe it's the first. When you get it all put back together, check and make sure forward and reverse disengage at the equal distance from the neutral point. You can accomplish this, by puting a mark at the point, where the pin on the shifter, rides in the shifter lock at the point of disengagement. Your marks should be the equal distance from the neutral point.

 

[F_R]

Re: '59 Evenrude Big Twin 35hp pops out of gear

I guess it is the age old question of which came first the chicken or the egg. Worn or loose linkage certainly will cause jumping out of gear, which in turn causes severe wear of the clutch dog and gear. On the other hand, worn dog and gear will certainly cause jumping which beats the daylights out of the linkage. They go hand in hand, and fixing one without checking the other is a waste of time, IMHO.

 

[1946Zephyr]

Re: '59 Evenrude Big Twin 35hp pops out of gear

About 90% of the lower units that I seen doing this was due to linkage.

Usually, the clutch dog isn't the culprit, unless you could fit a quarter in between the shift cradle and the groove in the clutch dog.

The last one I just rebuilt, had a perfect set of gears, and clutch dog. The shift cradle had about .010 gap, in the groove of the clutch dog, so I sold him a new one I had sittin around. Turned out, he had an 1/8" of up and down slop in the upper shift rod. I learned about this problem, from my very first customer in the business, when he had me rebuilt a lower unit, on his 60hp Gale Soveriegn. He was nice enough to have it all torn down for me, when I got there.

Unfortunately, after I got the lower unit all put back together, I noticed an unusual amount of slop in the upper shift rod. When I pulled the powerhead, I found that the bolt, holding the bellcrank to the shift rod was about to fall out.

BTW the chicken came first. After all, Adam and Eve came first to have three boys. So, a chicken must have come first to lay an egg.