Mercury 1965 9.8 HP: Need HELP with lower unit removal

judavis126 · #1 December 31st, 2006, 03:45 PM

I am trying to replace the impeller on my 1965 9.8 merc. I removed the 2 nuts holding the lower unit on. I got it down about 3/4 in. It will not go down any more. Am I missing something else. I have looked to try to unhook the shifter rod but I cant figure out how. Do I need to even unhook it? If it is all unhooked should I try to pry on it some how or what would you do?

Thanks

WillyBWright · #2 December 31st, 2006, 03:52 PM

It should drop off. The water intake screen under the antiventilation plate probably needs to be coaxed. The tab that goes onto the stud likes to grab threads as the gearcase drops. Push it forward with a screwdriver.

judavis126 · #3 December 31st, 2006, 06:04 PM

The bolt studs are past that point. The lower unit moves up and down about 1/4 in. Its like it hits a point and just will not go any further. I put some rubber in between the crack and then pried down but it will not budge past that point. How is the shifter rod and the drive shaft connected? What about taking the motor off then I could check out the rods inside the case. Any ideas will help.

Thanks

Laddies · #4 December 31st, 2006, 07:22 PM

I have seen the shift shafts on some of the older 6,7.5 and 10 HP engines rust to the point they won't seperate without prying on the unit till you pull the lower shaft out of the lower case then the gearcase has to be disassembled to put the shaft back in, you might seek some help from a marina

judavis126 · #5 January 1st, 2007, 01:08 AM

Is there a way to disconnect the shift rod at the top and then pull the complete rod out with the lower unit.

Anyone have an idea what it cost to get a marina to change an impeller?

Thanks

TriadSteeler · #6 January 3rd, 2007, 02:51 AM

Disassembling the shift mech. from the top down would be more work than it is worth.

Having to dissassemble the gearcase to reseat the shift shaft is worse (The expense in specialized tools alone is a killer)

My knowledge of the 9.8 is limited, but do they have the bolt underneath the trim anode like its bigger siblings?

Also, peer into the forward end of the lower unit where the separation is. The shift shaft should be right there. You may be able to get some PB blaster in there or get something in there to vibrate the shaft to loosen it (i.e. like a strap placed on an orbital sander).

Whatever you do, DON'T grab the spud bar. Like Laddies said, raw force will pull the shift shaft out from the clutch and because of the spring pressure, it can't be easily reseated.

TriadSteeler · #7 January 3rd, 2007, 02:53 AM

1 more thing. The marina route to change the impeller is hundreds less than dismantling the gear case.

As far as an actual number, I've heard anything from 50-250 for an impeller replacement.

Harker · #8 January 3rd, 2007, 12:36 PM

I had a heck of a time taking mine off the first time (67 9.8). Make sure it is clamped to something while trying to pull/wiggle it off. The bolts at the front and rear kept mine from sliding off freely. The bolt under the intake screen backed out with the nut the second time I took it off and it almost fell off when I loosened the other nut. You may have some corosion around the bolts that is wedging against the housing..squirt them with PB blaster and let soak and work it up and down to loosen the crud. If it's down 3/4" I'd bet the bolts are jamming in the holes.

judavis126 · #9 January 3rd, 2007, 03:06 PM

I have put a good amount of pressure trying to pull this off and it will not go any further. Is the shaft/rod splined or how do they go together. About how far up are they splined. Were the lower unit is at now it wiggles freely. It will move up and down about 1/4in but I cant cant get it all of the way back up. Is it the shifting rod or the drive shaft holding it on or could it be both.

Thanks

Harker · #10 January 3rd, 2007, 04:43 PM

Yes, the lower shift shaft and the driveshaft are splined.I'd say the lower shift shaft spline is about an inch long. The shift shaft rotates left and right to shift..not up and down. Having trouble getting it to close was a problem I had too. Someone gave the tip of setting the motor upside down and twiddling the shift lever until the upper shift shaft receptical was centered in the hole..worked like a charm. I still think you have an issue with the bolts. I didn't say this before..but...I used a 16" piece of 2x4 and a rubber mallet the first time I took mine off..I set the 2x4 on the cavitation fin and smacked it..some on each side till it came off..not recommending you do that but, I was desperate.