Yeah, maybe they just haven't heard about it yet. Could still be a lack of flow past the motor requiring a flow inducer shroud. Won't know until you pull the pump. If the motor shaft stickup is less than 1.5", the thrust bearing is the problem and a shroud will probably solve it. If the motor shaft is still 1.49" or 1.5", then it is probably the top bearing in the motor, which is the one I think they are having problems with.
Sigh.
First, let me say that this is a great forum and I really appreciate the time and effort people put into helping others.
I've decided to bite the bullet and replace the pump and motor with a different brand (likely a Goulds GS series but input is welcome). I have some misgivings about this since I went through the process of abandoning a VFD and installing a CSV in early 2016 (see long thread
https://terrylove.com/forums/index.php?threads/well-pump-help.63737/). I also had problems selecting a CSV that worked (see long thread
https://terrylove.com/forums/index.php?threads/pressure-tank-sizing.64492/#post-477223). Ultimately things seemed to work out well using a CSV 125 60-1 so I want to make sure that the new pump and motor will also work well with the CSV. (Note that the dead head pressure on the Grundfos when installed was 100 PSI and that the CSV sits 20' below the surface. Also, though never adequately measured, I suspect draw down is minimal and water levels pretty constant) The max pressure of the current system is about 67 PSI, so a 40/62 setting works pretty well. It originally took about 30 seconds to fill with no load (much to the chagrin of installers mistakenly looking for a 2 minute "cycle" time ) but with the degraded motor, it now takes about 1 minute to fill. If these numbers are good, I'm wondering whether the bearings are likely to go out again or whether the bearing problem is likely elsewhere. (I'll certainly add a cooling shroud.) Is it possible that the low flow rate (1 GPM) forced by the CSV is the cause of the failure even though it is for a short period?
This:
http://documentlibrary.xylemappliedwater.com/wp-content/blogs.dir/22/files/2014/11/GSSPEC-R1.pdf
Is a link to pump curves for Goulds. (It's too large to upload)
In looking at pump curves, I have some questions:
1) Does it make sense to take my maximum likely TDH (300), lowest reasonable flow needed (15 GPM with outside irrigation) and pick a pump that way?
2) How do I choose between the 13GS20 and 18GS15, both of which satisfy 1)? Is there a way to look at the Grundos pump curve and find a Goulds pump that is very similar without knowing the exact TDH but knowing the dead head Grundfos pressure?
3) With the CSV, how important is the minimum operational flow given the short amount of time the pump is running at 1 GPM.
4) Other than cost and power use, what is the downside to slight oversizing of the pump?