1983 Mercury 70hp not shifting into gear

[artu01]

Hello, I have a 1983 Mercury 70hp which jumped out of forward while traveling at full throttle. Now I cannot shift into forward or reverse and water pump also looks like it stopped working at the same time could all be related but I don't know. Why is my outboard not shifting into gear?

Any assistance much appreciated.

Thanks

 

[Hoosmatroos]

Re: 1983 Mercury 70hp not shifting into gear

Adjustment is probably off. Should not be related to your cooling issue. For your cooling you probably need te replace your impeller or you have a blocked channel. Remove your lower unit and check your impeller and adjust your shifting rod.

 

[dwco5051]

Re: 1983 Mercury 70hp not shifting into gear

Possible broken driveshaft.

 

[Maxz695]

Re: 1983 Mercury 70hp not shifting into gear

You need to drop the lower and inspect the driveshaft and shifter shaft If you ran this engine for some time and didn,t have shifting problems I suspect trouble with the LU

 

[artu01]

Re: 1983 Mercury 70hp not shifting into gear

Thank you for the replies I will check the lower unit hopefully tonight and post my findings.

 

[artu01]

Re: 1983 Mercury 70hp not shifting into gear

Hi

Looks like it might have stripped splines in the crank shaft. I have to get a closer look. Anyone know if this can be repaired successfully.

Thanks
Arturo

 

[Bosunsmate]

Re: 1983 Mercury 70hp not shifting into gear

Is the drive shaft seized in the LU?

 

[Hoosmatroos]

Re: 1983 Mercury 70hp not shifting into gear

I have replaced a drive shaft in the past but the other half was is perfect condition. Check the side were the drive shaft goes in. If that is stripped also then you have a challenge.

 

[Maxz695]

Re: 1983 Mercury 70hp not shifting into gear

If the water pump isn,t pumping the shaft is not spining if the shaft is not spining the clutchdog won,t engage. You either boke the shaft or stripped the splines. LU Removal is in your future. Hope the crankshaft is not effected. check the spline on it as well.

 

[Maxz695]

Re: 1983 Mercury 70hp not shifting into gear

If he driveshaft splines are shot. Your best bet is get another one. Re splining a shaft is possible but very expensive. I have a 60 HP shaft that fits 60 65 70 HP in decent shape with good outer end bearings and good journals. You will have to use your center mains reed blocks etc. Message me if interested. It is for a newer engine after 1982 I believe with a 132 firing order. The old firing order on the older models is 123 I,m running a 132 shaft right now in my 123 70 hp 1979. Just took swaping the coils wires on 3 and 2 cylinders. You can manually shift the LU when you get it off and spin the shaft to see if the LU is shifting correctly. as long as the splines are good and shifter properly it,s a good bet the crank splines are shot. View attachment 179161

 

[artu01]

Re: 1983 Mercury 70hp not shifting into gear

I have removed the LU, the drive shaft is good condition then I manually changed the gears into forward and reverse by hand and they shift good. Had a look up the drive shaft assembly and looks like the splines in the crank are stripped, there is also some corrosion, looks like I need crank replacement or repair. I rang the local outboard mechanic and he said the crank repair/replacement will cost around $2000 more than the motors worth, unless I do the work myself. The mechanic has a good second hand crank for $350, still trying to decide if I should try this myself, sounds complicated.

 

[Maxz695]

Re: 1983 Mercury 70hp not shifting into gear

It is a do able operation that if you have some minor skills can be accomplished. Having a manual first for information and instruction is best. Where here to help guide you through it if you want to do the job. Removing the bolts to remove the powerhead is probably the hardest part. Taking pictures of the engine componants will help assist you in reassemble. If you order the gaskets and sealers necessary to complete the job you can do this between several hours to a day or two depending on the amount of time you have to get it changed over. The crank I have needs a wear sleeve or good clean up of the one on it and it,s much cheaper than any you have posted here. You have to write me for info I cannot post it here in the forum. PM sent to your inbox, Along with the mini manual

 

[Bosunsmate]

Re: 1983 Mercury 70hp not shifting into gear

yep go for it, just set up a couple of pulleys to help lift the head.
You might be able to get a crank for cheaper than $350 as you will be getting it bare and not with conrods etc. Be careful with all cranks that the journals havent being ground down to change the bearing/big end size unless yours arent standard.
Are they needle roller bearings or are they sleeves? You really need to work out why it stripped in the first place too, it wouldnt be nice to repeat it after a rebuild. In my opinion a motor jumping to neutral wouldnt stuff the splines at all. Jumping to reverse could but that is quite a positional change with a shiftshaft cam lobe if thats what happened but i cant see how that would happen when in full throttle forward.
Maybe you hit something solid with your prop and the bushing didnt give.

 

[quicktach]

Re: 1983 Mercury 70hp not shifting into gear

Can you get a good look at the splines in the crank - to be absolutely sure they're damaged ? Try one of the scopes for looking in walls or can you get a digital picture and blow it up ? Wise to confirm before starting work on this.

 

[artu01]

Re: 1983 Mercury 70hp not shifting into gear

Thank you all for the posts, I will do a better check of the splines in crank first chance I get, I am currently on the road and wont be back home for another 4 days so hopefully next weekend I will be in a position to do some work on it, and know exactly what happened. Also the boat and motor is new to me so I don't know the history of it or the problems it had. Also when I did take it for a run I definately didn't hit anything. Thanks for the mini manual maxz695, I will have look and get back to you.

 

[artu01]

Re: 1983 Mercury 70hp not shifting into gear

Thank you all for the posts, I will do a better check of the splines in crank first chance I get, I am currently on the road and wont be back home for another 4 days so hopefully next weekend I will be in a position to do some work on it, and know exactly what happened. Also the boat and motor is new to me so I don't know the history of it or the problems it had. Also when I did take it for a run I definately didn't hit anything. Thanks for the mini manual maxz695, I will have look and get back to you.