Lower unit problem in a '67, 10hp Merc

[gmarshall43]

I'm working on a 1967, 10hp Mercury. I had a problem in the lower unit and I replaced the bearings in the forward and reverse gears. I also replaced the roller bearing on the drive shaft. I can put the drive shaft onto the pinion gear and onto the forward gear but I can not turn it. It seems to be hung up on the forward gear. The gear will turn freely by it self and I'm pretty sure I have the forward gear bearing pressed in as far as it will go. I do not have the reverse gear in. I'm wondering if the roller bearing was pressed in to far. Should it come out any pass the opening where the pinion gear sits? <br /><br />Thanks

 

[Laddies]

Re: Lower unit problem in a '67, 10hp Merc

It sounds like the fwd gear race might be cocked in the hsg, pull it back out ck the hsg and reinstall, warm the hsg with some thing and it will go in easyer---Bob

 

[Chinewalker]

Re: Lower unit problem in a '67, 10hp Merc

Hi Radar,<br /> What bearings did you use as replacements? Were the "GB-Series" bearings? If you used standard B-Series bearings, then they won't work. They "look" the same, but they are a couple thousandths off, with the OD of the B-Series bearing being slightly larger - enough that when pressed into the housing it will compress the bearing and lock it up. This is a common problem if you took the old bearings to a bearing store for them to mic up....<br />- Scott

 

[gmarshall43]

Re: Lower unit problem in a '67, 10hp Merc

I'm not sure what type of bearing it is. I'll have to remove it to see the number but the person replaced it with sealed bearing, not the roller bearing that was in it. With out the pinion gear in it, I can reach down in there and turn it freely with no restrictions. I can install the pinion gear to the drive shaft and it seems to seat ok with the forward gear. But I can not turn the drive shaft by hand. If I look up through the lower end I can see the drive shaft roller bearing coming through the opening where it is seated. I'm not sure if this was pressed to far. Where exactly should that seat?

 

[gmarshall43]

Re: Lower unit problem in a '67, 10hp Merc

Hello, I'm back with a couple of questions. One is that I replaced the gear bearings with sealed bearings and I was told that this may cause a problem with the oil flow. <br /><br />The other question has to do with the roller bearing on the drive shaft. I think I may pressed it a bit too far. I can see the bearing poking throught the bottom of the shaft. Does any one have any opinions/thoughts on these?<br /><br />Thanks,<br />Gary

 

[Chinewalker]

Re: Lower unit problem in a '67, 10hp Merc

Hi Radar,<br /> The sealed bearing can be used IF the plastic covers on BOTH sides are removed. It's also recommended that the thick grease in the bearing be rinsed out (kerosene, mineral spirits, etc.)<br /> As for the pinion bearing being pushed in to far, it should only be a problem if it's improperly supported (not enough meat to hold it in place and true) or if it's binding on the pinion gear. That may be the cause of your binding issue...<br />- Scott