IP485 Python CV Drive System

IP 485 2009 with just under 1200hrs. Thought I was the only 485 with premature problem with the CV joints on my Python drive. Did see previous post with problems on their 485s. Spoke with IP and PYI they spoke as if they were addressing the problem for the first time.

Problem had vibration coming from prop shaft with noise around Python shaft. Removed Python shaft and found the grease cap on the end that connected to the thrust bearing had been punctured by the Python shaft. When we disassembled the entire shaft we found the other end had the same problem and was about to wear through the cap. Both CV joints were worn on the extreme outer ends with the balls portion of the CV joint also wearing into the end caps. When we removed the CV disk from the spline portion of the shaft they were very difficult to remove as if they had been jammed on. IP and PYI both claimed that something must have shifted in the drive train to cause this. I have looked all over and have found nothing. After taking some measurements from the flanges at thrust bearing, engine adapter, and where the CV joints should be riding we think the shaft was to long. Everything was being compressed causing the CV joints wear in the wrong areas. I am working with Kevin Yutani at Constant Velocity of Ocala, Fl. We have ordered new CV parts and will shorten the new tubular shaft to the correct size.
Has anyone else shorted the Python shaft?
I will let you know how it works out.

mrrigy

I have an IP485 #25, 2004. Approximately, 1200 on the engine.

I had issues with my thrust bearing, which I replaced last year. I also believe that my CV joint is wearing improperly as well based how much play there is. Working with Python in the past, indicated that the tolerance of the length of the CV joint is very tight, like +/- 1mm. Outside of this tight range, results in improper ware, which sounds like what you are currently experiencing. Working with Python was a nightmare and I am currently looking for another source and, hopefully, a more reliable implementation so I am very interested in hearing about your experience with Constant Velocity of Ocala.

Based on my limited research, it seems that the Python drive was a weak point in the 485 design. I find it very interesting that IP has designed out the Python Drive for their current models of the 485, going with a direct connect to the prop shaft at the transmission.

Any feedback on Constant Velocity of Ocala would be greatly appreciated.

Spoke with Kevin at Constant Velocity and he said he spoke with you. We are going to build a new,shorter tubular shaft. Also will be getting spares. You might want to remove the shaft and check the ends of the grease housings to see if the shaft is making any contact with the caps. Also PYI says you should flip the shaft every 6mo to a year like rotating tires. I will let you know how I make out with the new one.

Thanks for the update. I am going to bring my Python Drive to Constant Velocity to replace the current CV joints with new ones on Tuesday, May 6th. They will also inspect the current drive for unusual wear. If the current joints are still serviceable, I will keep them as spares. Otherwise, I may order additional ones.

Haven't heard about flipping the shaft. Does seem that would let wear a little more evenly.

I am also planning to get a spare thrust bearing and additional rubber mounts. PYI sourced the rubber mounts when I replaced it last year.

Joe

Picked up new CV joints on Tuesday. Old ones were worn and it was good to have them replaced. The old ones will serve as emergency spares. Installed the new CV joints on boat yesterday and they seem to work fine. Kevin was very helpful.

Thank you for posting this issue. I'm having the same problem and difficultly finding the right folks to get fixed this fixed. Maggie Clipper 485-19 has about 1000 hrs on her engine.. I'll contact Constant Velocity.