Author Topic: upshift flare  (Read 630 times)

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Offline bbbbuick

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upshift flare
« on: October 01, 2015, 02:22:27 PM »
Hi all,

I'm trying to troubleshoot an upshift flare I am having during slow acceleration. It occurs only after trans warms up, then is fairly consistent. Under more throttle the shift is as normal. I also notice the flare when shift occurs in a corner. Manual shifting of the trans from L to D works as normal. Per advice from local hydramatic shop (only quality place around that does 60's era GM trans work) I tried a slight overfill of the fluid to check for short pickup pipe, as from what I can tell all replacement filters have incorrect length pipe and need to be trimmed. It didn't fix the issue. Perhaps related, or the cause, I also have no kickdown. It would seem the switch is bad, but I am not sure I tested it correctly.

Hoping to get ideas of where to start. What's the proper method to check trans downshift switch, and can that affect the upshift at all. Is there a switchpitch control that might be working incorrectly, causing a different stall point at the shift or would that feel different than a flare? If my downshift switch is bad, any ideas on where to source one?

Sorry for so many questions but as much as I read my chassis manual I can't find a section that clearly addresses this. Last details, 300ST trans was rebuilt 40K ago and other than the flare works as expected. Any help appreciated guys. Thanks.

Elvin
65 GS Convertible Auto

Offline bbbbuick

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Re: upshift flare
« Reply #1 on: November 07, 2015, 11:50:25 AM »
Bump. Kickdown switch testing method? Anything? All suggestions appreciated, thanks.
65 GS Convertible Auto