Pinion Height tool for Sportmaster

[TMI INC]

Hi,
I replaced the driveshaft and both tapered roller bearings. When I went to set pinion height I realized I do not have the right tool for pinion height for this specific case. I do not have the manual for this case, and it is back ordered at mercury so I'm a month away for the direct info. Does anyone know which tool specifically is required for this case. It is a 1:87 sportmaster on a 225 prom max efi 2002 vintage. engine s/n 0t430335

Thanks in advance

[97mirage]

I looked at my Mercury Racing gearcase service Manual...

For Sportmaster cases with 1.87 gears, the Pinion Height Tool number appears to be:

91-12349A05 (Disc 2, Flat 7)

Alternate Pinion Height Tool: 91-74776

Not sure if this is what you need and I’ve never built a Sporty but that’s what I see in the OEM Manual.

[wolfgangb]

Seconded. Recommend to set pinion height 0,65 to 0,66mm. It does take some patience and a looong feeler gage. Turn driveshaft by hand and measure in 3 positions. Add up, divide by three = median. This and the shimming of the forward gear will give you the backlash. Fwd gear shimming also important to limit prop shaft longitudinal travel (important for correct engagement of the clutch). I strongly advise you buy or borrow Mercury Bearing Preload Tool #91-14311A04 for these adjustments and follow the service manual #90-842009 to the letter.
These gearboxes, due to their intended use, require good/correct setting up equipment, the manual (although there are some textual errors in some paragraphs), and patience. The gearboxes look deceptively simple - they are not! Wolfgang (South Africa)

[FMP]

A couple of good gearbox threads on the go , very interesting info. Proper setup etc. When finally set, is a wear pattern checked or does the correct and proper care to achieve depth etc make that redundant?
Marking compound

[TMI INC]

Thanks very much for all the excellent feedback. The proper manual is backordered so I’m 1 month out. I operate a small dry land marina where we handle mostly stern drives, so I have almost every other tool. And I totally agree, high revs, high pressure, tighter tolerances. Lol

[patchesII]

Set it up exactly per the manual with good parts and it will live

[wolfgangb]

A couple of good gearbox threads on the go , very interesting info. Proper setup etc. When finally set, is a wear pattern checked or does the correct and proper care to achieve depth etc make that redundant?
Marking compound

Thanks for the reminder Frank - even with the preload tool, marking compound is the only safe way to ensure correct mesh.

[capteliminator]

You need the correct tool to set the pinion height first. Then you need the preload tool to check backlash and there is no need to check the pattern. Not sayin you cant do it any other way, but that's how the manual has ya do it. Look for sportmaster build tutorial by capt insane(?) on here, it is complete with pics.

[TMI INC]

Thanks for the info. I got the tool and set pinion height, but am still waiting on the manual. Can I trouble you for the forward hear backlash specs ?

[Capt.Insane-o]

.021-.025 is what to shoot for.

[Merc 2.5]

I know this isnt text book or even correct way ,but my cousin can take 3 lowers and build 1 with no special tools or even use a feeler guage, just a "feel" by hand , hes a very good mechanic but never really built outboard, I ran a 70 hp with one those lowers fir many yrs til I sold it ,then next guy sold it still workin, no certain reason for posting this except he either really gud at lowers or just real lucky haha
Of course we ain't talking big hp either

[patchesII]

I know this isnt text book or even correct way ,but my cousin can take 3 lowers and build 1 with no special tools or even use a feeler guage, just a "feel" by hand , hes a very good mechanic but never really built outboard, I ran a 70 hp with one those lowers fir many yrs til I sold it ,then next guy sold it still workin, no certain reason for posting this except he either really gud at lowers or just real lucky haha
Of course we ain't talking big hp either

That might work under small power but it will crater on a big power engine. I’ve been there and done it. Trae Appling does ours now. He’s a stickler for new parts and is anal about doing it exactly how the manual says. In the drag racing world he has a perfect record as far as I know. I ran a 1.78 XR6 case that is inherently not the strongest case under a very strong methanol 2.5 for years with zero issues and the fluid always drained out looking great