Hello.
I searched and searched online to find the "DIY" on fixing the common 2-1 downshift clunk on the 440T4 transmission. I read online somewhere about changing out the spring on the back of the transmission inside the cup (i think it's called a servo?) I guess GM revised that spring. Does anyone know the GM part number for it or a link on the fix website?
Any help would be greatly appreciated.
Thanks!

Hello.
I searched and searched online to find the "DIY" on fixing the common 2-1 downshift clunk on the 440T4 transmission. I read online somewhere about changing out the spring on the back of the transmission inside the cup (i think it's called a servo?) I guess GM revised that spring. Does anyone know the GM part number for it or a link on the fix website?
Any help would be greatly appreciated.
Thanks!

Hydramatic changed their naming scheme in 1989. A THM-440T4 is the same as a 4T60 which was last used in the 1990 Regals. The 1991 and later Regals used a 4T60E until the late 1990's when they changed switched to the 4T65E.. I sifted through over 100 transmission-related TSBs and couldn't find any info regarding a harsh 2-1 downshift or revised parts. A few of them did say to make sure the customer's car is doing a harsh 3-2 downshift and not a harsh 2-1 downshift though.