Problem with lower unit

[bassin98]

After running boat last weekend I noticed I have extreme end play on my prop shaft , about 1/4". There is no sign of water or metal shavings in grease. Did not seam to affect performance any. Do I have a broken snap ring, bearing going bad or what? Will I have to pull it all the way down? I have had lower units apart before , but its been over 20 years ago and I can't remember all the details. I guess the memory is the first to go.

[Ricardo Paragon]

Sound tom your second snap ring got loose. To do the job, you don't need take down the gear case, just drain the oil, and take prop off, so then you need take four bolts from bearing housing (torpedo), pull the torpedo out and you will see both snap rings, to get out, you need a special plier for that. and when you install back the snap ring, be sure you a choosing the right side edge toward reverse gear, how to find out.
Each snap ring have two edges, one is sharp and the other one is rounded.
The first snap ring, the rounded side must be toward to propeller, and sharp side toward to reverse gear.
The second snap ring is in oposite way, the rounded edge must be toward the reverse gear and the sharp edge toward to propeller.
Maybe it was miss assembled and the reason why came loose. Put the torpedo back with sealent at orings, and grease on the othe surface end, aply sealent at 4 bolts orings and torque at 24~26ft/lbs.

Take care,

RICARDO!

[bassin98]

Thank You I will pull it apart and let you know what I find.

[bassin98]

I just pulled out the bearing housing and there are no snap rings. Going by the parts books it looks like I have a 90 or newer gearcase. What on the newer housing sets your end play on the prop shaft?





Modified by bassin98 at 11:44 AM 10/28/2007

[ChampioNman]

You have a 1 piece drive shaft if that helps.

[gearcaseman]

If you had the locking tabs at 6 & 12 o'clock positions, you have a '91 or newer case. The rear brg. carrier's location has the most to do with reverse gear location. Are the machined grooves in the housing, where the tabs fit in the case, worn from front to back? Is the propshaft ring right in front of R. gear on the shaft? Does R. gear seem to be severe'ly worn where the ring contacts it? These are a few of the possibilities that could be creating increased endplay. The propshaft itself could also be worn in this area, adding to this increased endplay. It would be advisable to dissassemble the unit and find out what's happening before a major problem occurs.

[bassin98]

Thank you for the reply. The groves for the tabs do not seem to be worn. The gear,prop shaft and bearing housing all seem to be in good shape.Could something have hapened to the forward gear?

[gearcaseman]

Not very likely, as forward gear is "set in stone", so to speak. Did you find the .062 propshaft ring, right in front of your reverse gear? It sounds like it's missing, since all the parts you mentioned are in good shape. Has this situation occurred for some time, or did it just happen all at once? Also, do you have the small diameter propshaft, 1 3/16? These were used on the '91 and down cases, and sometimes parts can easily get interchanged and mixed with the wrong corresponding parts creating a situation like yours. Has it been rebuilt or gone into lately? There's got to be a simple explanation for this endplay. I'm starting to get curious about this one!

[bassin98]

I bought to boat used in the spring and just finished restoring it. I do not know any history on the motor. It is a 1986 150 so the gearcase has been changed. I can't remember seeing the shim , may be the problem. I will check tonight when I get home. I will also check the prop shaft diameter . I did not notice the end play before. I changed props and ran it and when I was done i checked to make sure the prop was tight and noticed the end play.

[gearcaseman]

O.K., Things start to get complicated around the '91 era, because of parts that will interchange in the cases, but were not meant to work for the '92 and up. If you have the small propshaft, the .062 ring is not required, however, if someone has used the big R. gear in this case, you will have excessive endplay. (#336561) You should have a 910994 or even a 910211 R. gear with the small shaft. Keep me posted as this is starting to get interesting

[bassin98]

My gear is a 910994. What do I have? I can't find this listed in the parts list.

[bassin98]

I found that gear listed for a late build 90 gearcase only which does not have a spacer. Wear do I go from here ?




Modified by bassin98 at 10:29 AM 10/29/2007

[gearcaseman]

Don, the case you have is a '91 down, no ring required. Look for excessive wear in the R.gear where it makes contact with the P.shaft. Also look for wear or damage on the front side of the rear brg. carrier where the R.gear thrust brg. washer fits. One other area to check will be the P.shaft itself, where it contacts R.gear. To do a thorough job here will require dissassembly B.T.W., you will have the small P.shaft. Hope this helps!

[bassin98]

Thank you. I decided to pull the gearcase off and take it to my dealer. I called him & explained it to him. He said he could try & find the problem.They are just as curious as we are.

[gearcaseman]

Keep me posted if you can, this is a good one!