Prop Shaft End Play Spec

[sam am I]

92 Merc 2.5L 175HP SN 0D103921

I think mine is waaay toooo much, I'll put a dial on it in a bit but, in the mean time............

I have read and searched the manual and here, seems to not really be a official spec documented on "prop shaft" end play (push/pull on shaft w/o prop on), anybody ever seen/read one in a merc document/manual/spec sheet? If so, can you print screen me a copy and/or link/quote where it can be found? S&F posts also seem to be not really knowing either.

I have "drive shaft" end play spec, that I found.

Gears/teeth (forward and back) and needles all look actually pretty good, no metal on mag plug (little powdered metal is all). Shifting although seems to be getting a bit persnickety........Seems edgy/touchie to get center and still have forward and reverse lock in good at detents...wants to pop out of reverse/be grindier if I don't go by reverse detent it w a bit higher throttle and come back to detent, then it stays in okay

Thanks a ton!!

 

[sam am I]

Also........If I adjust to make up for that (above), the forward lock-in at detent seems too far out............Questioning I suppose, might this difficultly to have/find both positive lock-ins on both sides at once be due to the end play I think is too much. That is, of course, if it's out of spec, which I can't seem to find.

 

[Faztbullet]

There is no spec but it will be between .040-.060

 

[sam am I]

Thx FB for confirming what we don't know, errrr do know. Think I re-looked for two hours last night......nothing!!

It measured at 0.0525".........Hmmm, guess merc wanted it to float a bit.

Well cool, I can go fishing this weekend then, muy apreciado

 

[Texasmark]

When you push on the prop you can expect ⅛-?" back and forth (end) play........what I have gotten on engines in the vicinity of 100 hp give and take.

Engine off. Shifter in F gear. Rotate prop CW looking from the rear and watch it closely. It should move back and forth as the teeth between the rear of the F drive gear and front of the clutch dog move over each other. This is your over run clutch action (F gear only) which allows your prop to turn faster than the engine rpms like when you are on plane and chop the throttle.....prop slows as the rushing water past it allows. Without the overrun clutch, if the prop and engine crankshaft were locked together like they are in R, when you chopped the throttle the prop rpm would chop too and guess what........you'd have to dig your teeth out of your windshield frame........somebody put on the brakes and forget to tell me sort of thing.

The F drive lockup mechanism gears resemble the teeth on a hand saw....slide over the hump in one direction and an audible clicking sound in the process, and lock (when the engine is driving the prop....acceleration) in the other.

If in doubt, go to a dealer and roam his sales lot pushing on the props on rigs sitting there.....BTDT. Helps to put your mind at ease.

 

[sam am I]

Thx TM, all good stuff from FB and you to know!! Prop shaft, clutch teeth, pinion teeth, F teeth, R teeth/bearings, needles all looked perfect and was back to tightening up the carrier, seemed a bit excessive somehow, so a bit of worry/panic ensued........Fishing was on the line here!!!

I didn't pull out the forward gear/bearing (didn't want to pull the pinion if I didn't have too) so wasn't able to inspect those closely, so naturally, I thought there was an issue inside still not knowing how much play was okay....whew

Still a bit odd, no numbers written on this...hmmmm

All is well however and it held 10lbs over night, oil is in........Look out fish!!

 

[Texasmark]

If everything else checked then the F gear functional parts probably are ok too. It and associated parts can be fished out under the pinion with it still in place.....BTDT in case you go back in at some point in the future.

On play numbers not published, no big deal as it is all spring loaded by the shift cam spring in the front end of the prop shaft and the spring picks up the slack.