2007 Mercury 250 Pro XS Torquemaster Lower Unit - Drive shaft snapped inside LU

[Longboardebo]

Hoping there are some clever mechanics out there that have solved this one already and have a recommendation (Don Weed I'm hoping you'll read this!)

S/N: 1B498673

The single piece driveshaft snapped right in the middle of the lower roller bearing assembly (shaft seal failed and water entered the LU housing).

So the standard procedure of removing the pinion nut clearly won't work as I can't grab what's left of the shaft as its buried down inside the case.

The best idea I've come up to remove the pinion nut is to attempt to rotate the pinion gear with a long punch and hammer while holding the pinion nut in place with the mercury pinion nut tool (#91-61067T03) and a block of hardwood shaped to support the propshaft and the pinion nut tool placed inside the case.

Failing this I've thought about drilling a large hole in what remains of the driveshaft and putting in a large (and long) easy out to rotate the shaft. But this is obviously a huge amount of work I would like to avoid, even though I have access to the tools.

I figure I can't be the first (nor the last) to have this problem, so figured I would throw it out there and see what else folks have come up with?

If the darn shaft had snapped just a tad lower it would have just fallen out when I removed the carrier and moved the prop shaft down... But of course that is not the way the universe seems to work :(

Thanks for any help and ideas!!

Cheers,
g

[JOE54]

try this take that long punch and try to spin nut off of d/s if you get it loose leave it on d/s just lil and wedge large screwdriver between nut and clutch d/s will usually pop out of pinion may have to hit propshft with malett or block of wood to move d/s has worked for me more than i can remember

[EuropeanAM]

try this take that long punch and try to spin nut off of d/s if you get it loose leave it on d/s just lil and wedge large screwdriver between nut and clutch d/s will usually pop out of pinion may have to hit propshft with malett or block of wood to move d/s has worked for me more than i can remember

+1

I've also used a pinion nut tool and a centering ring from another tool, locked the gearcase in gear and used the propshaft to turn the pinion gear (thus backing off the nut). When you get to this point, you're pretty close to the point that "it's junk unless I can get it apart" so you do what you have to.

[Longboardebo]

Thanks for the tips gents, especially the one about not taking the nut all the way off. Joe54 that was the trick!

I sprayed the pinion nut and gear top and bottom with PB Blaster and let it soak overnight.

I then put in the Pinion nut tool and wedged it up tight to the pinion nut by pushing on the drive shaft and with the long punch spun the nut off, it came off fairly easily after the first two hits.

About 4 revolutions or so into loosing the nut, I did exactly as Joe54 describes, I put in a flat piece of steel about an inch wide and 3/16" thick and 12" long and wedged it up between the nut and the drive shaft.

Two hits with mallet on the driveshaft towards the pinon nut and what was left of the driveshaft popped right out of the pinion gear. I then spun the pinion nut completely off and volia! Out came the stubby driveshaft and the drive gear. The driveshaft came out quite easily after that!

I can't thank you Joe54 enough for giving me the idea of leaving the nut on, that was the lifesaver!

So now the question is what parts to replace!

The LU had a lot of water in it, so I don't know if I should just go ahead and replace all of the bearings in the LU or not.

Should I worry about the prop shaft where the roller bearings come in contact with it? There is no pitting and it feels clean and smooth. Is there a diameter spec I can measure?

All the gears look clean with no strange wear pattern, the clutch teeth look great no worn teeth and the forward and reverse clutch teeth look great.

Frankly everything except for the bearings on the drive shaft (and of course the drive shaft bevel gear which I whacked with the punch) look great. I found no metal shavings or chips in the LU.

Its clear that the lower driveshaft roller bearing is what caused the failure, its completely fused into one piece with all the roller bearings still there. I knocked it out of the LU and it didn't wear past the race (which is a good thing!)

You guys have far more experience in terms of what's a must replace vs might as well replace since I'm inside it anyway, so I would appreciate your input on this!

[JOE54]

ssssshhhhhh its a secret only for BBC members your welcome , now for the fun part ,do you know for a fact that that lower brng DID NOT spin in that case , yes is good /no throw it away along with alot of other internal parts that i personaly would not use ,exactly why they stopped using those internals on higher HP engines they fail some even under normal use, thus gen 2 and verado style ;you got a manual for that gearcase ?????? if so use it along with lots of special tools youll need to do it right dont skip parts or pieces youll be sorry, good luck JOE

[Longboardebo]

do you know for a fact that that lower brng DID NOT spin in that case , yes is good /no throw it away along with alot of other internal parts that i personaly would not use - JOE

So I'm better than 95% sure the bearing race didn't spin in the casing, I say this because the bearing themselves took the wear as they are more than half worn away, and also it took a lot of effort to get the bearing race out of the case and there was no horizontal scarring on the outside surface of the race.

I have all the specialized tools so no worry there.

At the moment I'm thinking of reusing these parts:

1) propshaft
2) reverse gear
3) drive gear
4) clutch body and shifting parts
5) carrier body
6) shift yoke

What I I'm going to replace:

1) Drive Shaft
2) pinon gear
3) Pinon nut
4) all bearings and other components on the drive shaft
5) bearings on the forward gear - inside and conical and races.
6) bearing on the Reverse gear - inside and race.
7) Bearing on the inside of the carrier and race.
8) all seals

Any thoughts?

[JOE54]

pinion gear not sold seprate , sounds good

[EuropeanAM]

+1... will be a gear set (Pinion and FWD gear).

Otherwise, sounds good.

You WILL need to order three (3) different shim sets in order to properly shim the case. All shimming must be re-done from scratch.

[Longboardebo]

Hi Don,

I'll send you a parts list tomorrow for pricing.

Happy New Year, good to see 2020 get the heck out of here!

Cheers,
g

[Longboardebo]

Hi Don,

Sent in this parts list for quote

S/N: 1B498673
Drive Shaft Length: 32"

Drawing Qty # Part
25057 1 8 SHIM SET (#15-47397A1)
25057 1 9 GEAR SET, Forward/Pinion (#43-859321T04)
25057 1 10 BEARING ASSEMBLY (#31-828437A2)
25057 1 11 NOT SOLD SEPARATE, Cup (#NSS)
25057 1 12 BEARING, Needle (#31-30895T)
25057 1 13 RING, Retaining (#53-856823)
25057 1 17 SPRING (#24-78962)
25057 1 20 THRUST SPACER (#23-8241081)
25057 1 21 BEARING, Ball (#30-88957T)
25057 1 22 RING, Thrust (#681001)
25057 1 23 O-RING (#25-31534)
25057 1 25 BEARING, Roller (#31-817072)
25057 1 26 RING, Snap (#53-817071)
25057 1 27 SEAL, Oil (#26-815565)
25057 1 28 KEY (#28-30281)
25057 1 29 PLUG KIT, Drain - Magnetic (#22-8M0058389)
25057 1 29 SCREW KIT, Drain (#10-79953Q04)
25057 2 30 SEAL (#26-830749)
25057 1 31 TAB WASHER (#14-79447)
25057 1 32 RETAINER (#8M2011027)
25057 1 34 SCREW, (.437-14 x 1.75) (#10-66024)
25057 1 - SEAL KIT, Gear Housing (#26-816575A6)
3976 1 7 BEARING ASSEMBLY, Roller (#31-42647A1)
3976 1 12 SEAL, Oil (#26-8164641)
3976 1 15 GASKET (#27-858935)
3976 1 16 O-RING, (799 x .103) (#25-896522)
3976 1 19 NOT SOLD SEPARATE, Pinion Gear (#NSS)
3976 1 20 WASHER (#12-92721)
3976 1 21 NUT, (.625-18) (#11-35921)
3976 1 22 WASHER (#12-77674)
3976 1 25 DRIVESHAFT (#45-881938) 32" Length
3976 1 26 SHIM ASSEMBLY (#15-38657A1)
3976 1 27 BEARING, Tapered Roller (#31-48939A2)
3976 1 28 NOT SOLD SEPARATE, Cup (#NSS)
3976 1 29 SHIM SET (#15-42637A1)
3976 1 30 BEARING ASSEMBLY, Roller/Cup (#31-8M0146566)
3976 1 31 NOT SOLD SEPARATE, Cup (#NSS)
3976 1 33 CARRIER ASSEMBLY (#840836A2)
3976 1 34 O-RING, (2.175 x .175) (#25-8M0142854)
3976 1 35 SEAL, Oil (#26-66302)
3976 1 36 SEAL, Oil (#26-66302)
3976 1 39 SEAL KIT (#26-816575A2)
3976 1 40 GASKET (#27-430331)
3976 1 41 GASKET (#27-8172771)
3976 1 43 IMPELLER (#47-43026T2)
3976 1 44 COUPLING ASSEMBLY (#832942A1)
3976 1 45 O-RING, (.796 x .139) (#25-21836)
3976 0 46 O-RING, (1.046) (#25-35027)

[EuropeanAM]

You're now working with the Parts Department through the website, which has all of your pricing information (for the items you actually will need, rather than every piece in the gearcase, individually).