Thinkly
I recently had similar issues with my 3-year old Multiport Valve. I have the same model valve as your's.
My main valve issue was with the valve rotation, noisy, friction moving positions, etc. I didn't have the issue with the handle being loose (tension was ok, no issue with the spring).
I wasn't experiencing any of the usual leakby/sealing issues associated with a worn or damaged Diverter Seal (knwn as the "Spider" Gasket) P/N 271148 , so I left the original gasket installed at that time. I ended up replacing it later as a preventative action.
I tried the following things in this order:
- Inspected the Diffuser (grey cone-shaped part, P/N 271168) shaft and O-ring channels.
Both areas looked ok but I replaced the 2 O-rings P/N 191479 since I had the top valve assembly disassembled.
- Inspected the Spring. Since I wasn't experiencing the usual symptoms associated with a weak Spring, I didn't replace it.
- Inspected the Handle Washer P/N 271157 and the Spring Washer P/N 271160 . Both looked ok, didn't replace either Washer.
- Inspected the inner sealing surface of the Top Valve Cover P/N 271169 . I noticed some wear markings on the inner circumference where the Diffuser Shaft O-rings seal against the Valve Cover:
This is the part, along with the 2 shaft O-rings, that can produce the rotation/noise issues when moving the Valve Handle. It's also the area which will cause a water leak underneath the Handle when the valve is reassembled and installed.
- Lubricated the Diffuser Shaft, O-rings, and Top Valve Cover inner circumference surface with standard pool silicone gasket lube.
After I reinstalled the Top Assembly P/N 270067, I noticed that most of the same issues related to valve rotation were still present, although the rotation movement was smoother than previously experienced, due to the new O-rings and lubrication.
However, I still had the "noise" issue when rotating the handle. Also, after a few rotations to give the valve a small workout, a small leak developed under the handle.
I suspected the Top Valve Cover since the inner sealing surface displayed wear indications.
- Replaced the Top Valve Cover.
That fixed all valve issues: no rotation noise, rotation is smooth, no handle leak.
I have since ordered and received a new spare Top Assembly so I can swap that assembly fast for future valve maintenance.
I ended up replacing the "Spider" Gasket a few weeks later as a preventative measure since the Gasket was worn and was getting near its end of life cycle.
That Gasket replacement activity was no fun

but it was the first time I had done it. The hard part for me was in removing the originally-glued in Gasket from the gasket channels while minimizing channel area damage/scarring.
After talking with my pool tech guy about this, he told me "It's a 'bear' of a job, depending on how the original gasket is glued into the valve." That made me feel better about the time it took me to get that job done. I ended up using a small Utility Blade Knife to remove the old Gasket material which was a lot easier than using a small slot screwdriver.
The pool guy also said that subsequent Gasket replacements should go a lot smoother since often the new Multiport Valves have glued gaskets completely covering all of the channel surfaces.
I used the "spot" glue approach when installing the new Gasket, not covering the entire channel surfaces.
I used
Permatex Blue RTV Gasket Maker P/N 80022 for my Gasket glue after consulting various 'net sites and my local pool guy.