I'd be surprised if they did - to any extent that could be felt. 

I have them fitted on mine to help keep any road dirt / grime out of the joint,
( if there is any ! ), especially at this time of year when they spread lots of Rock Salt on the road.

I can't think why the Triumph designers would have included this seal unless there was
the potential for something to go wrong, such as corrosion etc, without them ?

Cheers 



 

Sorry. wasn't referring to mine. It was Trophied's on the trip to Arkansas earlier this year. The day I arrived there was the day his engine went south earlier that day.

It would be nice to meet up again, minus the blown engine and tornado warnings! I find myself stuck to the Trophy also. I just checks all of the boxes.

Here you go - it took some digging around in the garage to find them,
but I bought two sets of these ( four seals ) from Motorworks back in
November 2020 and paid GBP £7.74 for them including shipping.

The first Photo shows a comparison of the original Seals removed from my Trophy,
alongside the spare unused set of "BMW type seals" that I still have.
Note the smaller size of the BMW type, which appear to be of a sturdier type
( of nitrile rubber ? ) than the Triumph type, which seem to be more "foamy" 

The second and third Photo's are views of each side of the BMW seal type,
showing a recessed "cup" on one side, with a cylindrical protrusion on the opposite side.

Comparison :


BMW type - Recessed cup :


BMW type - Cylindrical protrusion :


Cheers 

stjim, no it is not legal in my state. I just think it is the sign of our times. The old work ethic is virtually gone anymore. Instead of saying "i'm sorry sir", we get excuses and reasons why we should understand why we got second or third rate service for a first rate price.  fortunately there is a great triumph mechanic at a different dealership but it is 200 miles away. He is more expensive but his reputation is excellent.