seperating upper and lower units

[pulleyman123]

I'm trying to seperate the lower unit from upper on my 1987 4.3L Cobra. I can't get them apart. I believe the problem is that the gear and pinion in the upper gearhouse are rusted together, I cannot pull the drive out. Any ideas on how to seperate the two units or unstick the gear/pinion? The gear is supposed to come out on the shaft, correct? or do I need to remove the gear then pull the shaft out? I have the manual here and it looks like it all comes out together, but I just want to make sure before I destroy anything further. Any techniques to pry, pull, wiggle the two units apart would be helpful too!
Thanks

 

[manofprawnz]

Re: seperating upper and lower units

It took me about 2 hours to get the units apart. I was not sure where it was binding up, did lots of WD 40 around the studs and light knocking everywhere, finally got a tiny separation of the two plates,got a small wedge in there, from there was able to work it back and forth, but what a job.

In my case there was an old 0-ring that was wedged up inside the splines, also the lower oil seal from the upper unit had rusted away and the spring behind it was also wedged in there. May want to open the top and try to work it from above.

 

[rebars1]

Re: seperating upper and lower units

Have you been able to get any separation between the upper and lower units? It me looonnnggg time to get mine apart. The front bolt had too much corrosion build up around it, even though it was stainless steel. It took alot of heat, tapping, WD, and wedges. The shaft should drop out of the upper gear.

 

[pulleyman123]

Re: seperating upper and lower units

no seperation yet, the top gear is pretty rusted, so I'm sure it's rusted all the way down to the prop. Is there any way to get a penetrating oil into their (onto the shaft)?

 

[rodbolt]

Re: seperating upper and lower units

on the cobra units there is no front stud, in fact from the factory no studs.
on the cobra unit the drive must be removed from the transom assy to seperate the lower from the upper.
other than the oring at the case mating halves there are no other seals for the upper/lower shafting.
make sure you have removed all the bolts including the one under the trim tab.

 

[pulleyman123]

Re: seperating upper and lower units

Think I got them all, six bolts in all. Four main bolts, one under trim tab and one next to annode bolt. Any recommendations on ways to support either lower or upper unit so I can wiggle the other. Now I just have it on my shop table (on it's side) so it's hard to get any leverage without the whole thing moving.
Thanks

 

[rebars1]

Re: seperating upper and lower units

Sorry, pullyman, mine is an Alpha 1 drive. I skipped over the Cobra part of your post. But, for a bench mounted drive stand, I used a piece of 3/4" plywood about 3' long and about 20" wide. I cut a "U" shaped slot at one end just big enough for the drive to snug-slide in and be supported by the caviation plates. I clamped the other end of the plywood to my work bench so the "U" hung out. I don't know if it will work for your drive.

If things are that rusty, you may not be able to repair it...

As a last resort, you coud take it to a marine shop and let them separate it.

Good luck.