Talked to a transmission rebuilder at a swap meet last weekend

He told me he never uses aftermarket shift kits anymore, just stacks factory plates carefully. Said it's about fluid pressure curves and I never thought about it that way - has anyone else dropped aftermarket kits for stock parts?

3 comments

3 Comments

milessmith5d ago

I rebuilt a TH400 back in 2005 and used a TransGo kit. That thing shifted like a truck hitting a wall. My buddy stuck with factory plates in his own truck and it still runs smooth 200,000 miles later. But I think the rebuilder's advice skips over how much modern aftermarket kits have improved. The new ones from companies like Sonnax actually let you dial in the pressure with springs and valves, not just stack metal. Stock plates are fine if you want factory feel and longevity, but if you want a crisp shift without the bang, the new kits work better. I wouldn't toss them out just because some old timer swears by the old ways.

kelly_craig5d ago

Man I miss when you could actually adjust stuff with a screwdriver on those old transmissions.

skylerrobinson5d ago

Aw man, I gotta disagree a little. There was just something about those old screwdriver adjustments that made you feel like you actually understood what was going on in there. These new kits are nice and all, but they take some of the... well, the soul out of it I guess.