'69 40hp LU driveshaft bearing

[baytonemus]

I opened up the lower unit yesterday which is from a 1969 40hp (thanks for ID-ing it, F_R), and the driveshaft (upper) bearing basically fell apart. Some of the pins looked very pitted and generally crappy.

It doesn't look like it will be too difficult to replace that, although I may need to fabricate a tool to get it out of there. Can that bearing be tapped in with a socket or is it too delicate for that? I don't have a tool made for pressing those in.

The lower part of the shaft looks good. At this point I've looked at quite a few driveshafts for these 40hp motors and many if not most of them have grooves worn in the area around this upper bearing. I assume that this is caused by people not watching the oil levels closely enough and failing to fix leaks???

Thanks!

 

[oldcatamount]

Re: '69 40hp LU driveshaft bearing

I've used a large socket to drive them in before and had good luck doing it, just take it easy and use a mallet instead of a hammer.

 

[baytonemus]

Re: '69 40hp LU driveshaft bearing

Thanks, oldcat.

 

[F_R]

Re: '69 40hp LU driveshaft bearing

ALWAYS install a needle bearing by driving on the numbered end of the shell. Pressing on the other end will destroy it.

As far as wear, yes low oil. And/or a bent gearcase.

 

[baytonemus]

Re: '69 40hp LU driveshaft bearing

ALWAYS install a needle bearing by driving on the numbered end of the shell. Pressing on the other end will destroy it.

10-4. Thanks, F_R.

As far as wear, yes low oil. And/or a bent gearcase.

A bent gearcase (or shaft?) would probably produce more wear on one side, right?

 

[F_R]

Re: '69 40hp LU driveshaft bearing

A bent SHAFT would wear on one side. A bent GEARCASE would wear the shaft all the way around because it is spinning in a non-aligned hole.

 

[baytonemus]

Re: '69 40hp LU driveshaft bearing

That makes sense. Thanks again.

 

[baytonemus]

Re: '69 40hp LU driveshaft bearing

I bought a cheap set of screwdriver/prybars from the bargain bin at the hardware store. One worked well to pry the seal out (after a couple of other failed, albeit more elegant, solutions). Then I fabricated a bearing removal tool by taking the big 12" pry bar, heating the end, hammering it to a 90? angle, and then shaping it on the grinder and wire brushing it smooth. This I used to drive the bearing out from below and it worked great. Here's a picture...



Question 1: Can I use a red scotchbrite pad to clean up the seal and bearing races?

Also, I was going to remove and replace the shift rod o-ring and gasket, but that gasket really didn't want to budge. It looks like it might be brass and kind of hammered down in there. So I figured that I might as well drive the bushing out, too, since it looks like I'm going to have to order a couple more parts anyway.

I had previously searched the forum and read about someone who had good luck using an old spade bit with a socket on the wide cutting edge to tap that out, so I gave it an try. That thing is really in there tight. I think I've got a good fit with the spade bit, but I'm pounding so hard now that I'm afraid of breaking the case.

Question 2: How hard do I dare hit that thing?

Other suggestions welcome. Thanks.

 

[baytonemus]

Re: '69 40hp LU driveshaft bearing

Question 1: Can I use a red scotchbrite pad to clean up the seal and bearing races?

I meant the bores, not races. Sorry.

 

[F_R]

Re: '69 40hp LU driveshaft bearing

Well the bushing should come out fairly easy. If you are pounding on it, your "tool" probably is bigger than the hole in the gearcase. Yep, you will break it.

 

[baytonemus]

Re: '69 40hp LU driveshaft bearing

Well the bushing should come out fairly easy. If you are pounding on it, your "tool" probably is bigger than the hole in the gearcase. Yep, you will break it.

Thanks, F_R. I can confirm that it is not bigger than the gearcase hole. The 1"+ hex end of the bit (that would fit in the drill chuck) is fully protruding through the brass washer. I can feel the slightly larger round part of the shaft behind that being gripped by the O-ring. It seems like a perfect fit, actually. That brass washer is just really wedged in there tight.

Now what should I try?

 

[oldcatamount]

Re: '69 40hp LU driveshaft bearing

I've used dentist picks before, to pick out the old o-ring. It's a tedious little job but, it's easier for me to do that then it is to drive out the bushing. Getting the new o-ring back down in there is not to bad, just fold the new o-ring in half and work it down the hole. You will probably need to work it down passed the slot it fits into and push it back up from the bottom. It will fit itself when you get it near the slot. Don't use anything sharp to push it with.

 

[Tim Frank]

Re: '69 40hp LU driveshaft bearing

I did this by running a 5/16 " NC thread into the brass bushing with a tap and using a bolt and a nut, and some carefully selected washer sizes, you can pull the bushing out....worked great.
Make sure that you can get the new bushing before you destroy the old one by tapping it.

I was replacing the same seal/bushing combo on a 6 hp E/rude. The dealers service guy told me that I could remove and replace the seal without removing the bushing.

Worst advice I have ever received.
Took me 20 minutes to get the seal out...I didn't bother fighting with the new seal, went to plan B, just ordered the new bushing and when it arrived pulled the old bushing, and replaced bushing and seal in about 5 minutes.

Be Careful not to tap too far!

 

[baytonemus]

Re: '69 40hp LU driveshaft bearing

I've used dentist picks before, to pick out the old o-ring. It's a tedious little job but, it's easier for me to do that then it is to drive out the bushing. Getting the new o-ring back down in there is not to bad, just fold the new o-ring in half and work it down the hole. You will probably need to work it down passed the slot it fits into and push it back up from the bottom. It will fit itself when you get it near the slot. Don't use anything sharp to push it with.

Meaning that you pick out the O-ring from above through the inside of the bushing without removing the washer on the bottom?

 

[baytonemus]

Re: '69 40hp LU driveshaft bearing

I did this by running a 5/16 " NC thread into the brass bushing with a tap and using a bolt and a nut, and some carefully selected washer sizes, you can pull the bushing out....worked great.
Make sure that you can get the new bushing before you destroy the old one by tapping it.

I was replacing the same seal/bushing combo on a 6 hp E/rude. The dealers service guy told me that I could remove and replace the seal without removing the bushing.

Worst advice I have ever received.
Took me 20 minutes to get the seal out...I didn't bother fighting with the new seal, went to plan B, just ordered the new bushing and when it arrived pulled the old bushing, and replaced bushing and seal in about 5 minutes.

Be Careful not to tap too far!

Thanks, Tim. I need some clarification, though. First, the parts drawing I'm looking at for this shows a bushing going in from the bottom, then the O-ring, then the gasket. What I'm looking at from the bottom of the case appears to be a brass washer that is tightly wedged. An image of the replacement part for that washer/gasket on marineengine.com does not appear to be brass, nor does the one that came with my Sierra seal kit. Is it possible that this was not the correct part or perhaps is the bushing in there upside down? It isn't a cup, is it?

Second, were you tapping the bushing after removing the washer/gasket? I'm not quite visualizing how you assembled the bolt, nut, and washers.

Thanks again.

 

[F_R]

Re: '69 40hp LU driveshaft bearing

Fer gosh sakes. That is a brass bushing, about 1/2" long, driven in from the bottom. The proper tool will knock it out of there.

If you were to be starting with the parts removed, first a gasket goes in the hole, then the bushing. But before you put the bushing in, the o-ring goes in a recess in the inner end of it.

I want one of those guys that claim the seal can be replaced through the bushing hole to show me. The hole is 1/4" diameter and the o-ring is .170" in cross section. Doubled, it is .340". That has to be crammed through a .250" hole, and straightened out at the bottom. I suppose it is possible, but I can knock out 10 bushings and do it right while you are messing with picking the old one out.

BTW, I am biased. I make those tools. But if your bushing is as tight as you claim, I don't want to sell you one. Better tap threads in it and yank it out.

 

[baytonemus]

Re: '69 40hp LU driveshaft bearing

Fer gosh sakes. That is a brass bushing, about 1/2" long, driven in from the bottom. The proper tool will knock it out of there.

If you were to be starting with the parts removed, first a gasket goes in the hole, then the bushing. But before you put the bushing in, the o-ring goes in a recess in the inner end of it.

Thanks, F_R, that's really helpful. Having never seen some of these parts, it's a little hard to tell, especially from the parts diagrams. Take a look at this image...



First, it shows the shift rod bushing, O-ring, and gasket above the gearcase, as though they go in from the top. Then, they are in reverse order from what you just described. Also, it's impossible to see the shape of that bushing. Based on this image and what I was seeing in my LU, I thought the gasket was on the bottom and that it had the same outside diameter as the bushing, which I assumed was a straight cylinder.

So, you've really cleared that up for me. I think I should be able to tap it and then rig something with the puller I used on the flywheel. I'll let you know how I come out. Thanks again!

 

[Tim Frank]

Re: '69 40hp LU driveshaft bearing

I read the drawing differently.

http://shop2.evinrude.com/Index.aspx?s1=1c99ab8229d29ff3c22dff01d7acb232&catalog_id=5&siteid=1

Items # 19, 20, 21 are in play and R&R from the top I think.
From the top, you would tap enough of a thread into the bushing to give the bolt a good grip, in fact now that I think back, I cut the head off the bolt and ran a thread at that end ~ 3/8" of thread....that end got screwed into the bushing and the other end with ~ 1 1/2 " of thread had the nut which I tightened down onto a socket which ID was larger than the bushing OD. A 5/16" stud would work fine, too.

The bushing draws out really easily, does not need a lot of force.

The bushing shows "limited availability" so as always, before you render a part unusable, have the new one in hand.
The manual should show you how to get that bushing out and reuse it if you want....I just decided to replace mine for 5 or 6 bucks and it made it easier to remove the old one....i didn't have to be so careful...

One caution; I am using my 6 HP as a reference, and the shift rod setup in the drawing link that i sent sure looks to be the same principal, but since we seem to have differing views of the same thing, you might want to wait to hear from one of the Gurus.
You should verify that the shift rod is 1/4" material. If it is larger (or smaller) you would have to use a different size bolt/thread than the 5/15 NC that I suggested.

 

[Tim Frank]

Re: '69 40hp LU driveshaft bearing

Fer gosh sakes. That is a brass bushing, about 1/2" long, driven in from the bottom. The proper tool will knock it out of there.

If you were to be starting with the parts removed, first a gasket goes in the hole, then the bushing. But before you put the bushing in, the o-ring goes in a recess in the inner end of it.

I want one of those guys that claim the seal can be replaced through the bushing hole to show me. The hole is 1/4" diameter and the o-ring is .170" in cross section. Doubled, it is .340". That has to be crammed through a .250" hole, and straightened out at the bottom. I suppose it is possible, but I can knock out 10 bushings and do it right while you are messing with picking the old one out.

BTW, I am biased. I make those tools. But if your bushing is as tight as you claim, I don't want to sell you one. Better tap threads in it and yank it out.

One of the Gurus weighed in while I was posting...and a good thing because it looks like I was wrong about the orientation of the seal and bushing.
If FR says they go in from the bottom....they DON'T go in from the top.

And I'm with FR, I'd still be assembling my LU if I tried to get that o-ring in with the bushing in place.
It may be "all in the way you hold your mouth", but I was very hapy popping out that bushing and gently seating the seal...piece of cake!

 

[Daviet]

Re: '69 40hp LU driveshaft bearing

I just finished doing one of these, the bushing, o-ring and washer go in from the top (water pump side of the housing). They can come out kind of hard, but doable.