@Greasemonkey
2019 Honda Pioneer 1000 (SXS1000M5L A) SOLENOID VALVE | Babbitts Honda Partshouse
If the update hasn't been done, you might want to go ahead and do it while it's apart.
You will need #1, #8, #21 and I would also get every bolt in that assembly. The bolts are really soft and stretch easy plus I know they have been in and out several times. If you use a torque wrench on them, double check the In# to Nm conversion in the manual. I've have found them to be off on some and the Nm setting or lowest is what you want to use.
The #1 clutch update housing adds a lot of oil cooling to the outer clutch. It was a free update through Honda and you might be able to still get it free if you have a good dealer.
Most of that machines problems were burning up clutches until the boot came off and trashed a cylinder.