I think it’s a little loose there are bearings under there that you can replace ,there are kits and some videos online showing rebuilding the sm420.check you newer trans the same way and see how much it moves for comparison .I would also take the top of the trans off to see what it looks like inside

Last edited by KEVINSKI; 11/06/2021 10:59 PM. Reason: More imfo
1954 Canadian GMC 9300
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