You can also replace the passenger side arm with an adjustable type - the arm itself is notched on the underside with a sprung clamp that allows the length of the arm to be altered simply by hand in seconds. They look identical to the originals (except for an extra rivet head), but this allows you to reduce the length of the arm to prevent the passenger arm slapping the windscreen trim. I have one on my Royal Blue Mk1 and it works a treat. Of course, the height of the swept area is reduced slightly but I've never found this to be an issue.
Might try that solution johnnyd, do you have a link to a selling site
I have never seen them advertised on EBay, but then again, I have never specifically looked for them. As they aren't an original fitment for our Triumphs, they probably wouldn't show up on a search for 'Triumph 2000 wiper arms'. The ones I bought were from autojumbles over the years. I may have a couple spare, but would have to check. As said, they look identical to the originals; stainless steel but with a chromed cap over the wheelbox and the same dimensions. They were no doubt made by the same manufacturer as the originals.
Excess travel resulting in the blade rubbing on the windscreen trim can also be attributed to slop /wear in the motor or wheel boxes. I'm sure this has been talked about before on here - excessive wheelbox wear can be addressed by removing the wiper motor from its bracket, undoing the large nut at the cable tubing, and gently pulling the cable out complete with the motor as a unit. Don't forget to remove the wipers first (!!) as the wheelboxes will spin round fast as the cable is pulled out. Turn the wheel boxes 180 degrees and then feed the cable back in. The wheelboxes then should be in a different position which should reduce any slop from wear in the teeth.
The only problem I have found doing it that way is that it is impossible to know which teeth are worn as one cannot see the cog. I did try it once but I had to take the dash out to enable me to take the back of the wheelbox off, mark the worn cog part, remove the cable, feed in (in my case) a new cable and adjust as necessary for it to run along the unworn part of the cog. Re-assemble. Bit of a faff but it did cure the "slap".
I think removing the dash just to reposition the wheelboxes to remove any slop is a lot of extra work. It is a 20 minute job to remove the wipers, wiper motor bracket, the electrical connector, and undo the nut at the start of the tubing before pulling the wiper motor and worm drive cable assembly out in one, turn the wheelboxes whilst the cable is out, then reassemble. The chances of the worm drive contacting the same teeth again when reassembled, I would say, is worth 20 minutes work! Perhaps the longest part of it would be regreasing the worm drive cable before putting it back!