Jim,
I don't know of any way the 2003-2005 transmissions would have received the improved reverse thrust washer unless the transmissions received full high performance rebuilds by one of the big builders at owner's expense.
The decision to "refresh" your transmission is probably more personal than factual. If it has been serviced occasionally it will probably continue to provide good service for quite awhile longer.
To make it nearly bullet proof for heavy and frequent towing and use of an exhaust brake it will require a significant upgrade and rebuild.
I had a complete heavy duty towing rebuild done on my '06 48RE by James Northrum, a skilled Texas rebuilder who was an authorized DTT builder. He used all the high dollar billet components available including input shaft and other hard parts. The job was not cheap but the result was impressive.
I have no experience with mild upgrades so can't comment on how much good a torque converter and valve body would do.
I had my 48RE rebuilt at around 135k miles because I thought it had been damaged. It had lost the tailshaft bushing and seal and a lot of fluid. I figured that was a good reason to have it rebuilt. As it turned out, when disassembled no damage was apparent.
I don't know of any way the 2003-2005 transmissions would have received the improved reverse thrust washer unless the transmissions received full high performance rebuilds by one of the big builders at owner's expense.
The decision to "refresh" your transmission is probably more personal than factual. If it has been serviced occasionally it will probably continue to provide good service for quite awhile longer.
To make it nearly bullet proof for heavy and frequent towing and use of an exhaust brake it will require a significant upgrade and rebuild.
I had a complete heavy duty towing rebuild done on my '06 48RE by James Northrum, a skilled Texas rebuilder who was an authorized DTT builder. He used all the high dollar billet components available including input shaft and other hard parts. The job was not cheap but the result was impressive.
I have no experience with mild upgrades so can't comment on how much good a torque converter and valve body would do.
I had my 48RE rebuilt at around 135k miles because I thought it had been damaged. It had lost the tailshaft bushing and seal and a lot of fluid. I figured that was a good reason to have it rebuilt. As it turned out, when disassembled no damage was apparent.