Upper pinion bearing race removal

jaschil69

Cadet
Joined
Feb 21, 2005
Messages
24
Getting closer with this project! The upper pinion bearing failed due to me not adding adequate lube. I have removed the pinion gear from the bearing carrier. The lower bearing, of course, came off with the carrier. The upper bearing fell apart upon removalI now have several pieces of the upper bearing. The outer race, the roller bearings, and the cage or retainer. Now, my question. Should the inner race come off of the gear shaft or is this a permanent fixture?
 

jaschil69

Cadet
Joined
Feb 21, 2005
Messages
24
Re: Upper pinion bearing race removal

Reason I ask is that the race that is still on the pinion shaft is chewed up
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Upper pinion bearing race removal

hello<br />the best special tool you will have without the service manualis a 10 lb sledge. beat the gearcase until its no longer servicable and get it over with. then go buy a case and go boating.<br /><br />there are some special tools required to remove the driven gear and bearing assy. you must chect it cause it was dry as well. there are some special tools required to properly press the bearings on and off the drive gear.<br /> it takes some special tooling to properly shim the fwd and aft drive shft bearings. the torque on the spanner nuton the horizontal shaft is 200ft pounds. the rolling torque must be set on the driven gear. <br /> right now you may have a rebuildable case. keep messing with it without the tools and service manual and you will have a junk case. the OMC dog clutch cobra upper is one of the more complicated cases. most the rest are simple. there are no upper and lower bearings on the horizontal or drive shaft.
 

jaschil69

Cadet
Joined
Feb 21, 2005
Messages
24
Re: Upper pinion bearing race removal

Actually, there isn't much to the upper assembly. Input shaft assembly, water pump, and pinion bearing carrier assembly. This doesn't amount to much. I am not doing anything with the case. The assembly is already out of the housing. Only thing I need to do now is remove the upper race. The puller I am presently using is just too thick to go in between the race and the shaft. Believe me. Putting spark plugs in a TT Dodge stealth is more complicated than the parts that go in this drive
 

jaschil69

Cadet
Joined
Feb 21, 2005
Messages
24
Re: Upper pinion bearing race removal

Also, horizontal would either have a left or right side. The bearings I am replacing are the two that reside in the carrier held down by the pinion gear retainer nut. There is an upper and a lower.
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Upper pinion bearing race removal

belive me by your inability to understand there is no upper or lower bearing on the horizontaldrive your in over your head. how willyou reset the drive gear depth while maintaining the shaft position? are you going to check the driven gear bearing? did you realize that plastic "gasket"with 4 holes is actually a non reusable crush shim for setting the rolling torque? did you realize that the aft bearing must be shimmed to correctly place the drive gear in the housing? did you know that there are 2 tapered roller bearings in the driven gear bearing carrier as well. they are most likly toast as well. if you are knowledgable with power transmissions and helical cut spiral bevel gears and tapered bearing rolling torques there are some tools you can eliminate by using a dial type inch pound torque wrench. white lead paste and a dial indicator. gears are gears and all have physical limits to live in. dont care if its a lathe gear head, a tractor tranny or a road tractor differential. all must be correct or the longevity suffers. but if in doubt "loose' lives. a gear tooth contact that is loaded to close to the heel or toe fails. gears without proper depth clearence fails. so buy a manual dont buy a manual, its your case. all we are trying to do is save you some headaches.<br /> I have seen to many upper cobra cases that would have been rebuldable on the first failure but after a patch the second failure took out the case. if you really want complicated replace the main shaft bearings in a hitach-seki CNC lathe :) . living in foat wuth I know you have heard of PENGO ind or GOEX explosives and even owen oil tool. I worked for all three at one time or another. worked for luke industries in joshua and burleson CNC as well as spacecraft machine and a few others. I know complexity when I see it :) when Dans machine shopwas in joshua I ran crank grinders and such as a part time gig :) when I was not playing at lake benbrook or eagle mountain or whitney .
 

jaschil69

Cadet
Joined
Feb 21, 2005
Messages
24
Re: Upper pinion bearing race removal

It is not the horizontal I am working on at this point. It is the bearings under the pinion gear. This would be vertical. The pinion gear lays horizontally with the bearing and race directly underneath it. They would be bearings 3 and 4 on the sterndrive.info site under "Cobra upper gearcase layout"
 

mdrinkwater

Cadet
Joined
Sep 3, 2012
Messages
25
Re: Upper pinion bearing race removal

I realize this thread is really old, but I had this issue as well, and Rodbolt is correct with what he says, however...my favorite saying is 'Can't never could' and I couldn't find anyone who would eve work on my 86 omc cobra....which left me to do it on my own.
I went to Harbor Freight, got a hydraulic press for $130...bearings for the pinion gear $80...found out I needed the bearing carrier, another $80...not to bad so far.
The pinion gear came out ok, the bearing closest to the pinion gear came apart, causing the race in the carrier to spin and chew up the carrier....everything else looked good, the issue is I could not get the race off the pinion shaft, after bending 2 bearing pullers, 1 homemade puller, I finally decided to take a dremel with cutoff wheels, go slow and cut out a section of the race....took 3 days, but it came off, with no damage to the shaft, the new bearing pressed on easy, I never messed with the drive shaft gear, and according to other posts, I should be able to reuse the shims, I just ended up buying the shim tool for $77 off ebay for the bearing carrier, and checking the backlash.
This is a huge job....not for the faint of heart, and you most definitly need the manual....but at the same time, a new upper unit was $1200...I figured the parts were a minimal expense, and as the boat was bought used, I have no idea what type of mechanic worked on it...worst case, I figured about $2000 to get this done....if the new upper is $1200, I have $800 to play with and see if I can get it done.
Yes, this is something you can do...with a lot of stick to it...and at the end, I have the satisfaction of knowing everytime I take the boat out it runs because of my work.
Rodbolt brings up some really great points, and we need to pay really close attention to what we are doing, and follow the manual...but it is something we can definitly do...I know, I did it!!!
 
Top