I bought my signature truck a cpl yrs age with 68,000 miles. It now has 108,000. The transmission has never been serviced as far as I know and shifts fine. I know I'm late I am planning on doing a drain and refill using the cooler line method. While I have the pan down I was going to replace the accumulator springs with this kit from Sonnax. I did this mod on my 1999 with a single spring kit. It shifted nice and firm. What I am slightly concerned with is with the age and miles could this shorten the life of the transmission or cause some damage?

Performance Rated Accumulator Spring Kit - 36948-18K - Sonnax

 

No, I don't believe it would cause any damage. Age and mileage are not factors in this case.