1988 mercury 35 - No reverse lock

[Baitcooler]

I replaced the impeller on this motor. When I went to launch the boat for the first time the motor kicked up when I tried to back it off the trailer. Based on some internet research I was concerned that the ramping cam was improperly installed.

After work today I dropped the lower unit again. The cam was in the correct position. With LU in neutral the upper transition from the ramp to the upper flat was centered, pointing forward toward the leading edge of the LU, away from the prop... call this 12:00. The upper flat, where the rod rests in reverse, occupied the 12:00 to 2:00 area.

So I then carefully reassembled with the controls and LU in neutral. I was watching from the port side when installing the lower unit and made sure the tip of the rod was on the ramp as I snugged up the two forward nuts.

The motor still did not lock in neutral or reverse. The claws start to come over the pin but not enough to hold it down. Assuming the rod is resting on the flat, it's like it's not long enough, or the spring isn't strong enough. I backed off the upper lock nut on the rod. It still doesn't catch. If I manipulate the claws by hand it's like the rod needs to move another 3/8" up in order to lock. Should I clock the cam one spline CCW to make sure it's on the flat?

I was expecting an assembly problem when I was examining it today, but now I'm concerned that the rod and cam are worn out? Is it common for them to wear enough that the claws can't hold down the motor when correctly assembled?

This motor has a hose coming out from the same area for a speedometer. I don't have a speedometer that operates this way. Is it possible that the hose is interfering with the rods movement? If I remove the hose do I need to plug the hole?

I need a game plan for when I drop the lower unit next. Any ideas? Thanks in advance for your help.

 

[Baitcooler]

Upon further snooping in the online parts catalog, I think I may be missing the 93336 push rod guide which appears to be not available. I'm able to move the rod left-to-right (if that makes sense) when assembled. In this case the cam is pushing it around not up and down. It looks like the guide restricts the push rod's movement to up and down....

I also had to pull a weird reach around move when sliding the lower unit up to align the shift shaft and the push rod. Does this guide align both? With the LU out does the shift shaft and push rod normally flop around?

Anybody have one of these lol? It's used on several motors from 35HP to 70HP.

 

[GA_Boater]

Did reverse lock work before the impeller replacement? The manual shows the proper clocking - I think it's the flat to the front in forward from memory.

The guide fits into the midsection. Some times it drops out when the lower unit is removed and some times it stays in place. It's runs about 50-50 when I drop my lower.

 

[Baitcooler]

The motor is new to me. The water out of the tell-tale was so terrible I replaced the impeller before attempting to run it on the river. It didn't occur to me to check the reverse lock before and after I replaced the impeller.

So, the guide was either missing the whole time, or it is in my yard somewhere from when I dropped the LU for the impeller work. I definitely cut the grass since then so if that's the case... it's gone, man!

I have another 35 parts motor laying on a pallet. On this one the reverse-lock push rod is tight with no side-to-side play. I'm assuming that means the guide is in place. I'm not excited about pulling both lower units off again just to recover the one guide I think is in the spare one. But I want to go fishing, and in general I'm too dumb to quit, so I'll probably do it tomorrow lol.

 

[Baitcooler]

It was missing the guide. My parts motor had the guide. I moved it over. Reassembling the LU into the midsection was much easier with the guide!

On the top threaded part of the push rod, I still had the lock nut backed way off from where I was trying to get it locked before and at first it locked itself down in forward. So watch out for that.... I had to pull the pin to get a wrench on the nut. Threading the locknut back to it's original position now has the motor locked in neutral and reverse, but free to kick up in forward.

Ready for another water test!

 

[GA_Boater]

Some times a guide is needed to navigate the perils of DIY repair. You have the guide. LOL

Hope you have a good water test.