10-31-2009, 06:39 PM #1
Stripped Drive Shaft and Impeller
The Back Story:
A few months ago I replaced the ware ring on one of my RXPs after it was ridden at WOT in less than 18 of water. The ring to impeller gap was over .060 and the impeller was bent up as much as 10mm on the trailing edge on two of the blades. I installed the new ware ring and straitened the blades. I also noticed the damage to some of the fins on the pump shoe at the time of the repair; however, I decided to let the damaged shoe ride as this is the guest ski. The repair went smooth as glass; I put the ski back into the lake and took it out for a spin. It preformed much better, but still not as strong as the ski I ride. A week ago, my wife tells me the ski feels slow off the line, I immediately new there was a problem because she is super timid when she rides. I pulled the ski out and found the impeller and drive shaft stripped, as seen in these photos.
I have inspected the motor mounts and they are all fine. The wear on the drive shaft runs the length of the spines. My only guess is something got wedge in the impeller weakening the spines to the point they could strip out. To be honest, I have never seen a splined shaft do this. I have broken output shafts of the gear box of my 240, broken the splined stubs off the drive axles of an M3, but I have never seen spines strip like this. Has anyone else seen this or had this happen to them.
I have gotten a drive shaft and an impeller is there anything else I should be looking for.
10-31-2009, 07:48 PM #2
I can't see how any kind of obstruction could have caused that...my guess is you weakened the splenes when you originally trashed it??
10-31-2009, 08:52 PM #3
i have seen this happen 2 times before only when the pump bolts were either loose or not thighend enough.
10-31-2009, 08:57 PM #4
I've seen it a couple times and it ussualy starts with a stock prop getting stripped and then it takes out the shaft.
10-31-2009, 09:00 PM #5
Wondering if there might have been a big piece of wood ,rock etc. at WOT causing sudden jam.
Only time I have ever seen something like that was a close ratio 5 speed out put flang on a Getrag tranny (BMW) I aquired. Spline damage looked the same as your pic.
Even that had me puzzled.
my 2 cents.....
10-31-2009, 09:00 PM #6
IF the prop was on a spline tool when you straightened the blades, maybe it is possible the prop was not properly seated on the spline tool and stripped when working on the blades.
+1 with Erik...Maybe the pump bolts were loose. I know with my ski, I often have to wiggle the pump to make sure the pump and gasket seat flush on the shoe. --J
10-31-2009, 09:25 PM #7
Thank for the input guys, the pump bolts where tight and the impeller was not on the the spline tool when I trued it up.
My plan so far is to replace the impeller, drive shaft, impeller bearing and the carbon seal. Anything else I should inspect or replace while I'm at it?
10-31-2009, 10:48 PM #8
- Join Date
- Aug 2009
- Beaumont, Texas
cut those plastic fins off, they are useless. plus you dont want them breaking and jamming on your impeller.
10-31-2009, 10:51 PM #9
11-01-2009, 11:18 AM #10
I have picked up a used driveshaft and a Solas 14/19 impeller from Green Hulk members. I'm going to take the stock impeller of my ski and put it on this one. Repair one ski and get to modify my ski, I guess thing could be worse.
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