Are these Splines bad?

[tonydiato]

This drive shaft was replaced less than 3 years ago. Could this be bad already? Sometimes the ski loses speed or thrusts(slips).

Thanks for your response.

Tony

Seadoo Gti 155 SE 2007.

 

[dcm0123]

I do not think it will cause loss off thrust or slipping but there is a lot of wear.
If it was slipping I would expect a grinding sound.
Do you have an alignment issue?
How bad is the spline on the mating piece?

 

[tonydiato]

There was no grinding noise. I did not take out the entire drive shaft so I do not know what it looks like on the other end. This was replaced less than 3 years ago so I am surprised it's worn that much. I do not know if the person who installed this aligned it. I know I rebuilt the jet pump and didn't do any alignment...i just put it back on. What would cause it to get that warm? Do you think the impeller would slip on those warn splines causing occasional slow speeds and a thrust when the impeller tries to catch on to it?

 

[dcm0123]

The alignment would be done by adjusting the motor mounts. There is no alignment on the pump itself.

This would not cause your speed issues.

The top edge of the splines would be worn if they were slipping and they were not.

 

[tonydiato]

The alignment would be done by adjusting the motor mounts. There is no alignment on the pump itself.

This would not cause your speed issues.

The top edge of the splines would be worn if they were slipping and they were not.

Thanks again for all your help in answering my questions. So, I do not need a new driveshaft at this time. I just need someone to check my alignment.

 

[dcm0123]

If it slips it may wipe out the mating spline.
If the mating spline is in good shape you my want to replace the shaft now.

 

[200mph]

Is there proof slippage occurs or just feels like it could be slipping?

Perhaps mark shaft and propeller to establish an index. Operate and check if marks are no longer aligned.

 

[ski-d00]

There will not be any grinding when the driveshaft slips. It will just slip under full acceleration at first and then gets worse quickly the more you make it slip until you can only go idle speed and any throttle will make it slip. From your pictures, I can't tell much, you should show a side view which will show the flat spots created. Whay was the driveshaft replaced 3 years ago? Was the impeller replaced at that time as well?

 

[tonydiato]

There will not be any grinding when the driveshaft slips. It will just slip under full acceleration at first and then gets worse quickly the more you make it slip until you can only go idle speed and any throttle will make it slip. From your pictures, I can't tell much, you should show a side view which will show the flat spots created. Whay was the driveshaft replaced 3 years ago? Was the impeller replaced at that time as well?

Yes. The driveshaft was replaced three years ago (2.5 years) and the jet pump was rebuilt last year with a new impeller. I also included some new photos. Let me know if you can tell if the driveshaft is bad from this angle. Also, the jetpump had the bushings for the 4 bolts. These plastic bushings are worn, but when I look to order them its only for a GTI Rental. Do I need to put these back on the ski since mine is not the rental class? Thanks in advanced

 

[dcm0123]

In my opinion they both show considerable wear. It is best seen from the angles below. The areas I circled in red look like pockets where there "should be" metal.
You could run it and when they start to skip. replace both. The risk being if you are far from shore, you may need a tow.

Was this properly greased?

 

[tonydiato]

It was not greased. The ski is up for sale. I may just replace the driveshaft.

Thanks,
Tony

 

[tonydiato]

Also. Could the wear on this also be because the mechanic didn’t align the engine with the new driveshaft?

 

[dcm0123]

It was not greased.

Based upon the above, this is the cause of the wear-

 

[ski-d00]

Definitely wasn't greased at all and they both look bad to me. When the leading edge of the splines wear like that they act as a ramp and promotes slipping. Start over with new and use the BRP synthetic grease this time.