Stripped splines
- Thread starter ngerk
- Start date
- Location
- North Carolina
Looks like full engagement to me.
- Location
- Long Island
a lot of things can cause splines to strip.
- not enough engagement
-Improper engine alignment
- worn pump bearings
-worn o rings in the mid shaft. So it doesn't hold grease and lets water wash out everything in there.
- Landing the ski upside down all the time ( crashing) causing the motor to move the shafts-couplers at crazy angles
- Non oem shafts(both midshaft and driveshaft) that are not the same quality metal as oem
-Shafts that are 20 years old and have the wear from a ton of hours.
In your case its probably got hundreds of hours on the shafts and as you're pushing the ski to do tricks its finally given out.
get a new oem mid shaft, check your bearings, carrier and seals and hit up @Sasquachcrap and he will get you a high quality drive
shaft so you can get back on the water!
- not enough engagement
-Improper engine alignment
- worn pump bearings
-worn o rings in the mid shaft. So it doesn't hold grease and lets water wash out everything in there.
- Landing the ski upside down all the time ( crashing) causing the motor to move the shafts-couplers at crazy angles
- Non oem shafts(both midshaft and driveshaft) that are not the same quality metal as oem
-Shafts that are 20 years old and have the wear from a ton of hours.
In your case its probably got hundreds of hours on the shafts and as you're pushing the ski to do tricks its finally given out.
get a new oem mid shaft, check your bearings, carrier and seals and hit up @Sasquachcrap and he will get you a high quality drive
shaft so you can get back on the water!
Thanks. I’ll be hitting you up for another driveshaft.
Great info! Let’s see if we can get down the list. Spline engagement seemed to be ok. I aligned the engine best I could tell so I hope this isn’t it. I used the cold fusion tool for the pump alignment. I rebuilt the pump before assembly beginning of the season and it still feels great. My dumb self rebuilt the midshaft but didn’t get orings so this could be one issue. How would I know? Maybe when I pull the midshaft, it’ll be clear of grease? Ski has landed upside down of course. Anything to help here besides learn to land stuff haha? The midshaft was oem from a GP760, maybe the splines weren’t great, honestly don’t know. Driveshaft was custom length cut by Sasquachcrap. Driveshaft was new this season.
- Location
- central florida
Note to op: look closely at the 2 o rings inside near the end of the midshaft. You'll note that they are worn flat. Water was able to enter the inside of the midshaft then carrying with it those elusive, tiny "grease worms" that ate all the grease- causing that wear.
Anytime I remove my engine, I pull the m/s, just so I can replace those o rings!
Anytime I remove my engine, I pull the m/s, just so I can replace those o rings!
- Location
- North Carolina
Besides alignment, grease is the most important key to not stripping shafts. Even with perfect alignment you will strip shafts without grease. New o rings and grease often.
O rings definitely could look better. Inside of the midshaft is basically dry besides metal dusted everywhere.
- Location
- Long Island
I usually pack a a few finger fulls of grease inside the midshaft so as it heats up and moves around it can keep lubricating. It spits some and makes a mess inside the intake duct every once in a while, but the shaft stays lubed. every time i pull my pump / midshaft i clean it all out and repack it
Freakrider
X247
- Location
- Tampa Bay area
This is so true...I pull my SB 155 pump 3 times per year and grease re-pack it after stripping one shaft after one year use with no maintenance. I bought this latest driveshaft from you and it's been holding up with proper maintenance.
Quinc
Buy a Superjet
- Location
- California
Watch the pump, midshaft, and engine alignment videos:
Pretty positive it was lack of grease after taking it apart. I greased upon assembly but it was my fault for not putting in new o rings. Lesson learned but at least I know the cause.
Watched those a few years ago. Good videos to show the concept but the pump alignment video is only good if your driveshaft tube is centered with the midshaft bolt holes. My current hull isn’t so eyeballing it wouldn’t work very well.
Freakrider
X247
- Location
- Tampa Bay area
Another issue I failed to mention is excessive runout on custom driveshafts is going to wear out midshaft seals prematurely. The only option then is to monitor the grease washout frequency or replace the shaft with one that is true to oem specs; along with new M/S seals . Couch oem shafts that have been cut and resplined meet this criteria.
Freakrider
X247
- Location
- Tampa Bay area
When you install your midshaft, it's imperative that it's bolt holes line up perfectly without putting midshaft in a bind regardless of where the driveshaft is centered in the bulkhead.
Quinc
Buy a Superjet
- Location
- California
I use an old midshaft with the shaft part removed to confirm that everything lines up centered etc. Can also use the CF tool. The video helps explain how to adjust the driveshaft and where to shim etc.