Unfortunately the rear shock is sealed unit and a non servicable part. It's cheaper to buy a custom made one than replace with genuine Triumph .
.... and will be a huge upgrade in quality. A real noticeable difference to the ride. If you are canny replace a shock before it goes "off." Stick the OE back on when you punt it. Unfortunately, I'm not. Two pre-load adjuster failures on my Honda CT under 30k miles. 1 under warranty. 2nd, out of warranty, replaced at great expense (£7-800 IIRC) with a Nitron unit. Pure, silky damping. Feel the difference with one click of adjustment. The OE Honda unit was a similar eye watering price to the Explorer price mentioned.
Unfortunately mine was broken from the inside. It was some sort of a long needle like shaft that had snapped. I ended up buying a wilbers type 641 Competition suspension.
I was an original owner of the first series of Explorers back in 2014. I rode the bike one up and two up (occasionally) with Jesse luggage side cases and a top box (about 50% of the time) for touring. At 13,000 miles and just into my second year of ownership the rear shock collapsed during a group ride. When I left the house it was fine, by the time I got home it was like riding on a pogo stick. I contacted Triumph through my local dealer and was told I was not going to be covered under warranty due to the age of the bike and the mileage. I was not too happy. i ended up getting a new shock and the front forks reworked at the Beemer Shop in California. I can recommend the work they do, the bike was radically different with good suspension. Not more understeer, no more tire cupping and best of all the rear let you get the power down better.
It has been 2 months and 11 days of wait till I finally got the bike back. I didn't had proper time to ride the bike yet but all the noises are gone and the ride is more stable. I'll post the photos of old disassembled suspension and some photos of the new one. Thank you all.
