Clunk on 1-2 up shift and 2-1 downshift
I started hearing/feeling this 1-2 shift clunk a few days after I installed my FRPP 3.73s, Mark 8 DS, and polyurethane trans and x-member mounts. It sounds/feels like two solid pieces of metal hitting and I can feel it when my hand is on the shifter. It doesn’t do it every time I get a good ¾ to full throttle 1-2 shift, there seems to be no rhyme or reason to it. I’ve checked all my trans, x-member, and rear diff mounts. The u-joints in the DS are new, they were replaced when I had the DS balanced. I’ve checked every nut and bolt that I loosened for the install and they are all tight. Another thing, when I ran it at the track last week, the 1-2 shift sounded/felt probably 3x worse. On the streets it will clunk once when it does it, but on the sticky track it clunked like multiple times on all of my 4 runs. At first I thought it was wheel hop, but I don’t get anything like that when I launch. I don’t even really know what wheel hop is supposed to feel and sound like and I don’t know if its common on the 1-2 shift?
Just recently I noticed a clunk or hesitation type feeling when the car downshifts from 2-1 when coming to a stop. Its kind of like the feeling when you have something heavy in the trunk that’s not fastened down, you have to come to a quick stop and whatever is in the trunk rolls up and hits the back of the seat. Just like the 1-2 up shift, there seems to be no rhyme or reason to it? The fluid level is good, I thought the two noises might be related by an internal problem until I went to the track.
Sold = 96 Thunderbird