1986 5.7 upper gear case shim question?

[stackz]

so, apparently there are 4 different shims?

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0911 (678-681). they are all very similar aside from thickness/color. I took mine apart to check bearings and tore my original. its an orange color (well whats left of it). I have no clue which one I need?

I was thinking to ERR on the side of caution and go with 0911680 (.005") as thats "middle of the road" on thickness but any help would be appreciated?? these gears are expensive as hell and I dont wanna chew them up when they were otherwise good...

I'm trying to look at this from an automotive standpoint as in rear axle gears with a crush washer where you can put past on them and look for a wear pattern that is acceptable. without going into all of this (I mean I do have the paste and will do that) but these things are either at trolling speeds or wide open throttle all the time so maybe marine is a bit different? or am I looking too much into it and just slap some RTV on the mating surface and tighten it down and be happy? lol.

 

[kenny nunez]

The plastic shims under the input retainer are for setting the pre load on the input shaft bearings. Used bearings are happy with 6-8 inch lbs of rolling torque. Without the shims hold the retainer tight against the bearings, measure with a feeler gauge under the retainer, then subtract 2 thousandths. That determines which thickness/color shim required. Then recheck the rolling torque.
There should be 006-008 backlash when the gears are mounted in the gear case.

 

[stackz]

hmm, ok, so clean the mating surfaces, bolt it back together, then from inside the case push in on the driveshaft and measure behind the gear attached to it? lets say I have feeler gauges but no clue what you mean. is there a youtube video on this?

I mean I found a video on how to take the thing apart...but not one on how to put it together...

 

[kenny nunez]

You should get a genuine OMC Cobra service manual.
I like the video. Why are you taking the gearcase apart?

 

[stackz]

You should get a genuine OMC Cobra service manual.
I like the video. Why are you taking the gearcase apart?

it sat in a field for 15 years pulled as an outdrive from the boat sitting literally in the grass... I was making sure it was good inside and not all full of water and that the gears were good and such. as you can tell, I do not have a service manual. had no clue all I had to do was pull the top cover off. I pulled the driveshaft out first and got gear oil all over my feet (I was wearing sandals...wife was really mad as I smelled like gear oil all afternoon haha).

then I got the bright idea to look at videos on youtube after looking at the interchange on boats.net and seeing multiple "shims" instead of just a "gasket". if I had known to just pull the top cover...I would have never touched the stupid driveshaft but hind sight is 20/20 lol.

 

[stackz]

to further explain....just helping a friend as he knows I'm mechanically inclined. I "assumed" the driveshaft would just pop out once the retainer was loose. didnt realize it would have come with the stupid gear and bearing as well. thats also what I get for "assuming" on a 100*F sunny day. he had another driveshaft that was bare. was like ok. probably has a cir-clip like an automotive cv joint.

if you are wondering why we were replacing the driveshaft...welp...this is what the one on this unit looks like:

had I know all this fun stuff. I would have told him to return the one he had and go online and just order a new yolk shaft and swap it on after pressing off the front u-joint. but since it was open, decided to look at everything and clean it out to put in new gear oil.

but yeah, this is what I get for being a good friend who cant turn down a case of beer and concert tickets for helping an idiot friend who takes his stuff apart and leaves it in the dirt for a decade...

 

[kenny nunez]

Does the inside of the drive look as good as the driveshaft?

 

[stackz]

Does the inside of the drive look as good as the driveshaft?

inside of the shaft looks great to be honest. even the u-joints looks fine. oil was clean and no water mixing or intrusion. swap this part and it'll be fine...well once I figure out which shim I need to use. and yeah, I'm going to replace the o-ring as well while its open. I just need to figure out where to use the feeler gauge. will take pics of where I think I need to use it.

 

[kenny nunez]

Under the front bearing retainer where the shims go. That is where you place the feeler gauge while holding pressure on the retainer. Once you figure out the clearance select the shims and subtract .002. The rear bearing cup is what sets the back lash. The shims provide the preload on the bearings.

 

[stackz]

ok, so measure across here? (yes I know its not completely together in this pic)

and man this thing is a darn tight fit! having to slowly hammer it in. how am I supposed to properly measure this thing if I end up accidently hammering it too far on? I'm done helping him with this thing after this. going back to outboards lol.

also, in case you were wondering, here's the inside of the case. some dirt fell in there but it will clean up just fine.

you can see the u-joints in the first pic as well. fine shape. are the u-joints press together? I have a 6" vice can I do like on automotive driveshafts and just use a large socket on one side and a small one on the other, press out one side cap, and then swap/repeat? to get the yolk off or is there a trick to that as well?

 

[kenny nunez]

The joints r&r just like a auto drive shaft. To ease your mind just replace the the shim with the same color that was there before. And it will be good.
I had all the special holding fixtures for the stern drives. They are just a real PITA to work on without them. Clamp the drive on a Workmate if you have one or a pair of saw horses just below the cavitation plate.

 

[stackz]

The joints r&r just like a auto drive shaft. To ease your mind just replace the the shim with the same color that was there before. And it will be good.
I had all the special holding fixtures for the stern drives. They are just a real PITA to work on without them. Clamp the drive on a Workmate if you have one or a pair of saw horses just below the cavitation plate.

you have been soooo very very helpful, I cannot thank you enough! its what makes me want to pay it forward when I can help people as well.

continuing on...

I have a saw horse I was exactly thinking of.. here's my issue though...which is why I posted this originally...so...100*F and just rednecking it...tear it apart and look at it. tell him, yeah bro you gonna need a new yolk at least. open it up. yeah it looks good. we'll clean it up and slap it back together and put it on vs your one that is all tore up. why didnt you call me ten years ago? oh yeah, you went through some stuff...you could have at least kept everything in the shed...

anyway, popped it all apart and didnt really see much of note so yeah, good usable upper section. counted gears. they matched up (he actually did it right lol) so no weird issues with gear ratios. yes, we will clean it out and prime/paint it and put new seals on. install and let him go. god knows I owe him as he is a brick mason and helped me. I go to look up the "gasket" for the driveshaft. and low and behold...fuuuu

OMC Sterndrive 5.70L 350 CID V8 OEM Parts Diagram for Upper Gear Housing | Boats.net

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#30 is not a gasket...voila, its a thickness shim...fuuu. ok well thats all good. lemmi look them up online real quick. this thing is pink and they normally are colored...
0911681 (.010") https://www.ebay.com/itm/313632914305?epid=1335102422&hash=item4905fa7b81:g:VEMAAOSwimFhEdI3
0911679 (.003")https://www.ebay.com/itm/175177455094?hash=item28c963d5f6:g:cXwAAOSwj6ViGkcp
0911678 (.005")https://www.ebay.com/itm/255559007666?epid=1937694983&hash=item3b8080fdb2:g:TKMAAOSw8BRik~1F
0911680 (.005")https://www.ebay.com/itm/203845360571?epid=1940358726&hash=item2f76215bbb:g:SmsAAOSw3DtiGqRd

man, I looked them all up on ebay because people love giving pics of actual parts...I was hoping for a smoking gun of PINK...

here's pics of whats left of his:




.5mm and you can see in bottom right that its not pink. its kinda bland/whitish? and an online conversion shows .5mm as being being .019" I think I need the 911681 "shim" and just send him on his way after tossing the dipstick gasket and the driveshaft gasket and throwing whatever weight gear oil in it. let it eat. I already told him, I'm not a marine mechanic and there is no warranty for his douche baggery and he knows this thing. it may tear itself apart. at this point I told him, dont crawl back to me cause I dont care anymore and will shed no more sweat after this is done.

but again, thank you so much for your help!!

 

[stackz]

so should I use the 0911681 (.010") shim?

 

[kenny nunez]

That is going to be the best way. Just be sure that you can feel some “back lash”. Just like a ring and pinion. Too much will use be a little noisy but you know what no “back lash” can do.
When filling the drive there is a vent screw mid point on the side of the lower gear case, when the oil comes out of it put the screw back in and continue filling just like an out board.
It is also 100* here in the New Orleans area.
I had a stern drive shop for over 30 years. I closed up in 03 but so far I still remember a few things about them.

 

[stackz]

gotcha. a little "clicky clacky" but if I use GM gear mesh yellow lube and I get a good pattern on the face I'm good? so they can be a little loose like rearend gears? they almost look like dog tooth gears which is why I'm kinda going...uhhhh....

 

[kenny nunez]

The thing I liked about the stern drive repairs is the shimming tools. With those you knew it was right.
Is the gimbal bearing good?