Ayuh,..... How old are the bellows,..??..??
If more than 5 years, I'd replace all of the rubber parts, 'n the lower shift cable, while you have it apart,.....
Hmmmm. My bellows, gimbal bearing, uni-joints and shift cable are now into their 14th year. I check them every 6 months, and still not even the first inkling of any age or wear related deterioration. And that's the same story for all my customers and friends.
Chris.....
... thought it was more related to fresh water and shorter northern summers....