TOPIC: 68 Merc 1000 Shift Cable Adjustment

My motor isn't shifting into reverse until the throttle is starting to engage.

In forward, when you shift out of neutral into forward you feel it engage. You have idle for about half of the range, then the throttle kicks in.

In revers, it doesn't shift into gear until it's starting to rev. That kind of makes it difficult to get into gear. Going backwards full throttle is not fun.

My question is how the heck to i adjust the cable?! I have a Seloc manual and it give all of a page and a half to adjusting the shift cable.

So by that i believe it should be easy. I watched a couple of videos on youtube but can't find one exactly like my setup.

It looks like i should be able to pop the cable up and turn the brass barrel to move the cable forward or back. The throttle is on the top and the shifter is on the bottom.

There is a spring lever going through the housing where the brass barrels are, but i don't see what it does.

I'm sure it's something simple I'm missing but i can't find it!

PLEASE HELP!!!
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1 914 310 7086 Dave

So i called Dave today and he helped me out!

Turns out you need to remove the cable from the motor to adjust it. (putting that here in case someone else runs into the same thing)

You just take off the 2 nuts.

Push in on spring lever, turn it 90 degrees and pull it away from the brass barrel.

Then lift them out.

He told me if the white plastic spacer is missing from the shifter barrel i can move the one from the throttle to the shift because the throttle doesn't have as much problem with play as the shifter.

I have spun the barrel as far as it would go. It is up against the brass grommet on the cable. It shifts into reverse before the throttle engages, but just barely.

I'll know more when i take it out. It's storming now but i'm tempted to go to the river anyway!

Still no reverse! Once or twice we did get the boat to go backwards. But most of the time it would just grind.

I have the cable adjusted as far as the barrel will go to pre-load towards reverse.

What else could be wrong?

Are there any adjustments in the control unit? can you adjust the cable on that end?

Does the control only take a bump to get it into forward? I had a problem with my 1975 Mercury 500. It had a square shift shaft and it was well worn and had a lot of free play. I am pretty sure your motor does not have a square shaft, mostly likely a splined shaft. However, it still could be worn and you would be loosing some travel in that. Do you have problems getting it back into neutral?

It sounds to me like one or both of the following components are worn too much.
Either the shift cam on the bottom end of the lower shift shaft is worn too much or the plunger on the front end of the propshaft is worn too much - or - a bit of both.
There are two options to correct this.
1) Replace these two components with less used ones,...OR
2) Determine the amount of wear totalled between these two components and install a washer of this total amount to correct to amount of movement required.
Either of these - of course - requires a total disassembly of the lower unit, and hopefully the 'dogs' on the Reverse gear & the 'clutch' are not too horribly worn to respond to a better set of a cam & plunger.
Thom

PSUrandy wrote:

Does the control only take a bump to get it into forward? I had a problem with my 1975 Mercury 500. It had a square shift shaft and it was well worn and had a lot of free play. I am pretty sure your motor does not have a square shaft, mostly likely a splined shaft. However, it still could be worn and you would be loosing some travel in that. Do you have problems getting it back into neutral?

Mine has the splined shaft. I just put the lower unit on, got it from Tim on the forum here, so i'm sure the splines are not worn.

Before i adjusted the cable it would go into forward about half an inch after coming out of neutral. It goes back in neutral fine.

Thanks!

PS. You're just up 83 from us! We live down in York.

Dr_Frankenmerc wrote:

It sounds to me like one or both of the following components are worn too much.
Either the shift cam on the bottom end of the lower shift shaft is worn too much or the plunger on the front end of the propshaft is worn too much - or - a bit of both.

I've only ever seen 2 of the shift cams so i don't have a lot to go on. I'll have a look at them and see what i see. Then i'll post some pics.

As I recall, the one cam had a sort of ramp on it. If i didn't position that correctly would that cause a problem?

There are two options to correct this.
1) Replace these two components with less used ones,...OR
2) Determine the amount of wear totalled between these two components and install a washer of this total amount to correct to amount of movement required.
Either of these - of course - requires a total disassembly of the lower unit, and hopefully the 'dogs' on the Reverse gear & the 'clutch' are not too horribly worn to respond to a better set of a cam & plunger.
Thom

I just bought this lower unit from Tim and when we were at his shop and shifting it manually it seemed to shift fine. He would have probably replaced any parts on the unit that needed replacing.

I pulled the LU this morning and found that I put the shift cam on in a different position than the original. this may be the problem?

The picture with the white cam is the originl LU. the black cam is the new one.

Incidently, the original white cam will not come out. is it stuck Orr is it attached? The black one comes out fine. since the white one is stuck I assume it is in the correct position.

New


Original

After talking to Tim it looks like it is either the control box or cable. it takes 2 inches of travel to shift into reverse. but it doesn't go back to neutral until right before it goes vertical.

I'm stumped.

I took apart the control box and lubed it up. here is a pick if the shift lever. does it look too warn?

I installed a new shift lever tonight. Still the same problem.

While I had a helper to turn the prop I removed the cables from the motor end.

I can shift it easy as can be by hand sliding the post the cable connects to. it pops in reverse near the end of travel in the guide.

So that only leaves the cable, right?

Joe Poole was helping me out a lot. He sent me detailed instructions on how to test the cable travel. I didn't do that yet. too frustrated! but tomorrow after work ill give it a try.

Here is what i've replaced and still not reverse:

1. Shift lever in control box.
2. Both throttle and shift cable

I've adjusted the shift cable numerous ways, with it in neutral i adjusted it to exactly slip on the shift connector, or with a slight per-load to reverse. NOTHING!!!!

Today we took the boat out. I un-bolted the cables from the motor. I tried actuating the shifter in the mother by hand to reverse. It slides the whole way back to the end of the channel. Still it will not shift into reverse!!! Shifted into neutral and forward by hand no problem.

When i put on the new cable, i ran the motor with my garden hose. It shifted in the driveway.

So why won't it shift in the water, but it will in the driveway?

Thanks.

It will shift on land because there is no load on the prop. You have a problem with either the shift shaft, or the shift mechanism in the L/U.

still no reverse.

talked to 2 members, Tim and Joe, and tried many more things. thought maybe upper and lower shift shafts were off by a spline. so I spent some time after work trying to get the upper shaft to turn more towards forward while putting the pu back on. every time I raise the pu the shift linkage moves back to center.

I did have the cables disconnected. upper and lower in neutral.

tested the movement of the upper shaft by marking one spline and observing its travel while shifting to forward or reverse. they were the same.

tested movement of lower shift shaft on old and new. they both seem to only need to move 30 degrees from neutral to shift forward or reverse.

any ideas how to test the upper shaft further?

here is a picture of the upper part of the linkage. it looks like the arm is welded to the shaft. is that right?

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here is where the linkage insists on resting in neutral. the mark on the tap coincides with the location of the threaded shaft when the cable was on.

It still sounds to me like you need to open up the lower unit, inspect, and be prepared to replace the shift cam and the cam follower.
Until you do,...You simply won't have Reverse.
Doc F

I have to agree with you. we've replaced everything else so ill stop beating a dead horse. since this is a temporary LU I will live without reverse until the original is rebuilt. thanks everyone !

I just started having the same problem with my '63 Merc 850. I know I saw a thread here about which lower units with the stainless shafts that would fit on mine, but I can't seem to find it. Thom, I think you were the one that had the answer, as usual. I think that would be the better way for me to go, instead of rebuilding the 50 year old one and end up with seal problems in the future because of a pitted shaft, ect.
Bill

I don't know if this will help, But it is worth saving in case needed later.

So I got my original Lower Unit back from Tim and the reverse on it works with no problem.

Except that i put the shift lock cam on wrong and it won't drop the bar. Ramps in the wrong position, but that's easy and it's my fault.

So i'm sending the replacement back to have it fixed, no charge!

After all this i'll have 2 working Lower Units AND all new cables and shifter internals.

Finally got around to dropping the LU and moving the cam. Have a page from the service manual with a picture of the cam in reverse and neutral. So i know it's in right.

But it still won't lock.

Is there an adjustment to the bar that goes up to the hooks?

When i shift the bar moves up and down and seems to move the hooks. But in reverse i can still lift the motor off the stop bar manually.

Just went back to it before i hit submit on this post.

I shifted into forward and dropped the LU a couple a inches. The bar that goes up to the hooks is not moving down, even though the ramp on the cam is out of the way.

What do i check on the bar and hooks? i can't find anything in the manual.