1971 Chrysler 70hp reverse problems...HELP!

[Philip0812]

Hi, I am new to boating so please be patient. My 1971 Chrysler 70hp will not shift into reverse. When I try to shift it makes a "grinding" sound like it doesn't want to go in. I changed the lower unit oil when I purchased the boat and found no water or metal. I used the marine oil from Walmart, I think supertech. I have been told by some that if my engine has an electric shift, that the lower unit oil that I used could be the problem. I'm not sure that the engine has an electric shift. If the oil is the problem, can anyone tell me the correct oil to use? I don't want to force it into reverse, I'm afraid it will break. Also, it will shift into forward and it still makes a little grinding sound but once it's in forward it works great. Thanks for any help....Philip

 

[eurolarva]

Re: 1971 Chrysler 70hp reverse problems...HELP!

Not sure on the 70 HP but on the smaller ones there is a nut about 3 inches long that has reverse threads on one side and forward smaller threads on the other side. This is the coupler between the upper and lower shifter. It should be located in the motor leg. Turning this nut will adjust the shifter travel on the lower unit. Before messing with anything else disconnect battery and spark plugs for safety reasons. Place shifer dead center in the neutral position. Use your finger to turn the prop both directions. It should spin freely in both directions with no clicking noises. Have someone slowly shift forward while turning the propeller by finger. When propeller locks in place have the other person stop moving the shifter and mark its position. Go past neutral to reverse and do the same thing. If shifter is not centered in above test the shifter needs to be adjusted. You may be too far forward on the shifter so you can get enough reverse, however if you go too far the other way you may have reverse and not be able to achieve forward.