Chrysler 65hp clutch dog problem

[las]

Ok cool if you have a look this weekend but don't stress yourself over it.
Do you have different washers to compensate for the play? Ah just saw you would order the correct one!!
I must admit there is many things about this lower unit I find very strange and poorly engineered. But that being said I can see many other brands are constructed the same way, and maybe there are some limitations due to it's size and manufacturing cost.
This is actually the first time I take an outboard gearbox apart.

 

[jerryjerry05]

The Chrysler lower units were actually one of the best out at the time. There really isn't too much different than the new stuff out there now.
The newer, bigger ones (from 88 to 95) can be rebuilt without shim tools.

 

[las]

jerryjerry it looks well constructed but at the same time poorly engineered, at least compared to a cars differential.
Now I haven't studied the service manual to any length, but as far as I can tell there's no adjusting forward gear in relation to the pinion gear. The adjustment of play in the prop shaft makes no sense at all for me. The end play depends on the thickness and wear of the "so called" thrust washer adjacent to the forward gear. It doesn't take into consideration where reverse gear is regarding the pinion gear. And yet the adjustment is made with the reverse gears bearing race, called a spacer????? It makes zero sense too me.....
I have the same problem with the way the drive shaft is shimmed, I find it lacking to say the least.

 

[jerryjerry05]

"as far as I can tell there's no adjusting forward gear in relation to the pinion gear"
That's measured and set by shims under the bearing cup for the pinion gear.
Get the factory service manual, you don't need the exact year, just something close.
You WILL need special tools to shim the pinion gear height.

 

[las]

I do have the service manual for my engine but I don't have the tools for pinion adjustment. But I'm not changing anything and hope to just reassemble and sail.
What I meant was, there is no "easy" way to adjust the forward gear in relation to the pinion gear. I know you can alter the height of the pinion but that doesn't make the relation between gear and pinion correct. It can still be to close or to far away even though pinion height is ok.
I think it's a compromise of cost, complexity and expected lifespan.

 

[las]

Ok I got the parts, well most parts, and now I'm planning the rebuild.
The first concern I have is with the prop shaft spool.
It appears to be unpainted and just raw alu, it was somewhat corroded and I'm wondering how to avoid that again if at all possible or even desirable since the anode bolts to it.
I first thought of painting it but leaving the gearcase side and anode contact patch free of paint. But I'm afraid the paint could chip of and end in the waterpump blocking it!
But then again would potential small flakes of paint block it? What about all the other stuff floating around in the water......
Painted or not I think I will use gasket sealer on both O-ringed flanges when assembling it, as well as on the shaft seal to spool like it was.

 

[jerryjerry05]

Try to clean it the best you can, sandblasting and powder coating works.
Just make sure the bearing is out of the carrier and doesn't pick up sand or you'll be fixin something else.

 

[las]

Just finished painting the prop spool and about to install the pinion and driveshaft.
However I have stumbled across some conversion issues.
The Chrysler service manual calls for 600 inch lbs and if I'm correct that's 67.8nm, not a lot!
The Seloc manual calls for 85 ft lbs or 116 nm, almost double.
But I suspect the seloc manual have the data for the larger engines as this is the lowest HP with the one piece lower.
Is 67.8nm equal too 600inch lbs? I just need to be sure....

 

[Nordin]

Yes las you are right. Factory service manual calls for 600 in lbs and it is 67,8 Nm.

 

[las]

Thanks Nordin...
I'm really stressed right now!
After tightening the pinion nut I went ahead and put in the prop shaft and the yoke. Then I tried to engage the gears and to my horror the forward gear would only engage lightly if at all. It could have something to do with the shaft not being aligned 100%, but still! I wouldn't take the chance and assemble all just to find a skipping forward gear.
I was on a timer because I had just given the new pinion nut a dab of red loctite and if something was to be done, it was NOW.
Applying pressure downwards on the shift shaft, the prop shaft would bind from the square nut on the shift arm, touching the plunger attached to the dog.
I figured that limited the forward throw and that being over 40 years old and probably well worn, some play had developed all over the shift system.
So I decided to grind a round grove in the "nut" and shorten the shaft.
Maybe all would have worked fine had I just continued. But maybe I've just discovered a way to achieve more forward throw in the shift linkage.
And maybe I made a bad mistake....... Time will tell. Maybe I've just discovered a design flaw.
Like Nordin mentioned earlier there is very little throw in the shift shaft. I didn't measure it before, but now on the bench, I have 11mm from reverse to forward!
Edit: after measuring again, this time with calibers I now have 13mm throw from forward to reverse.
It's seems like a lot more than before.

Look at the pictures and tell me what you think!

 

[Nordin]

Las your measure of the total throw from reverse to forward and vice versa seams pretty right.
I have measure my spare LU and have roughly 12 mm measuring with a folding rule.
From my experience when I changed LU on my sons 65Hp the throw from when the clutch dog starts to engage the gear and until it is fully engege is about 2 mm. This also seams correct as the height of the dogs in the gear are about 2 mm. This is not to much to play with so it is important to adjust the shift rod and remote cable right and not have something bending in the shift linkage.

 

[las]

The numbers ad up! I also tried measuring from when the gear start to touch to fully engaged and I have around 3,5-4mm now. So it seems I have a little more positive engagement. Or if I'm correct, double almost!
It could be something else going on in my system, but I felt that the forward didn't fully engage and that reverse had a lot of throw. So much that it would lift the prop shaft out when the carrier was not in place. Now it feels quite good in forward too.
But you are absolutely correct that there is where little room for fail adjustment before you destroy the forward gear.
When you go mess with your next lower leg next time, try to see if you can feel the shift lever touching the gear dog plunger when pressing on the shift shaft and if you do, then I think this could be a great improvement.
But if it turns out you can't get the lever to touch the plunger then this has no effect!

 

[Nordin]

Las I will check it soon, I am in order to disassemble the spare LU cause of the incorrect prop shaft end play.
Maybe in this weekend.
Then I have to correct myself about the height of the dog in the gear.
It is 4 mm (0,16 in) not 2 mm (0,08 in) as I said before. Sorry!
The throw at the shift rod is not equal to the height of the dog cause the movement of the clutch dog is coming from a pivot of the gear shift arm.

 

[las]

Ok if you have 4mm measured on the shift shaft then it's the same and my initial problems must have been a misaligned prop shaft, not allowing the shifter full forward action.
Did you receive a new "spacer"? Or are you using one from a spare unit?

 

[Nordin]

I have not order a new thrust washer "spacer" yet, if it is that what you mean.
I have to disassemble and measure the one that is in it now.
I have about 1 mm end play now and the service manual calls for about 0,20 mm.

 

[Nordin]

Las I pulled the spare LU apart tonight and I will update the measurement.

The height of the dogs in both gears and the clutch are 4 mm (0,16 in).
The fully throw from reverse and forward is 12,4 mm (0,49 in) with the shift rod turn all way down in the shift arm and 12,7 mm (0.50 in) with the shift rod turn 2 turns out from bottom.

I have 4 mm (0,16 in) in throw at the shift rod when the clutch dog starts to engage untill is fully engaged. It does not matter if the shift rod is turn all way down or turn out 2 turns from bottom.

Now I also have measured the prop shaft end play.
I have 0,60 mm (0,024 in) play and the thrust washer which is in now is 1,42 mm (0,056 in) thick.
Factory service manual calls for 0,010 plus/minus 0,001 in end play.
Out of this I need a new thrust washer 1,78 mm (0,070 in) thick.

I will order from Franz marine.
BTW: There is only a thrust washer between forward gear and clutch dog.
No thrust washer between clutch dog and reverse gear.,

 

[las]

It's strange you have more throw with the shift rod turned 2 turns out! Could that be the small protrusion of the threads making contact with the clutch dog plunger? Did you feel for any resistance when applying pressure on the shift shaft?
Otherwise it should be the same regardless if it's all the way in or 2 turns out.

Did you hear any gear whine when sailing with the lager prop shaft play?

Yeah I know there's only a washer at the forward gear, I just don't like that they call the reverse gear thrust bearing race a spacer!!!!

 

[Nordin]

Las, I have not checked for any resistance on the shift shaft yet. Will try tonight.
The different in throw from reverse to forward depending on how far the shift rod is out from bottom can be a measurement error from my side.
I noticed that when the dogs at gear and clutch dog are align perfect and at the bottom of each other the spring pin is at the end of the milled slit in the prop shaft.
This is at the reverse gear because I can not se at the forward gear.
It is still left in the gear housing.
But as the height of the dogs are 4 mm and the throw from when the dogs start to engage and until it is fully engage also is 4 mm, I suspect it it has done the whole travel as is could do.
I have not use the LU with the wrong prop shaft end play.
The LU I put on in the summer is still at the engine and it is working as it should.
The LU I have in my workshop are the one that jumped out of gear and I changed the forward gear.
When I reassembled it I notice the wrong end play.

 

[las]

I think you are correct about the 4mm travel front and back being full throw, I must have made some small mistakes when I tested before final assembly.
But I'm okay with making the curve cutout on the shift lever, I know now that it will not interfere with the plunger if for some reason I was able to achieve that much throw.
My plan is to make sure that the travel from reverse to forward on the throttle control box equals 13mm travel now.
Maybe that involves altering some of the levers in the system, I haven't decided yet.

 

[las]

Ok now I'm closing in on the problems!
It appears that the total throw on the shaft going into the gearbox coupler is only 10mm from full forward to reverse! That means I'm missing 3mm, almost the 4 mm needed to fully engage either forward or reverse.

The day it skipped gears I tried adjusting it to as much forward bias as I could and like I said earlier, it wouldn't engage reverse correct then.

I suspected the lever the gear cable attaches to was mounted incorrect. I already tried setting the shift cable one hole down and that made the cable bind. I then thought the lower rod going forward was supposed to go in that hole and that was the fault. See pictures in post#3.
I then looked in the service manual to see if my suspicions were correct, nope! The extra hole was not even supposed to be there.
Meaning the previous owner had the same problem and trying to fix it that way and for some reason gave up on it.

Well, I now think the majority of the play comes from the remote control box as the handle is quite lose and wobbly.
Then I found this beauty on the german ebay, like the one I have but without trim/tilt in the handle. Mine is broken anyway so perfect!