So, if I read this right, just replacing the converter with a beefier unit may not mean that we're in the clear unless we make those other mods. Do I have that right?Good decision to install the zip kit…
For more context around 6L80 TC and related failures: The factory pump pressure regulator valve (pump cover) and TCC regulator valve (lower valve body) wears on the “balance spool” end of the valve allowing oil to bypass the valve sealing surface. This results in insufficient converter clutch pressure (in a nutshell) which, combined with the .020” converter clutch (way too thin), leads to premature converter failure. This is known to frequently happen inside of 100k.
All 6L80es should receive at minimum those two drop-in valves installed, along with the Sonnax boost valve, on overhaul to prevent recurrence of those issues. The Sonnax zip kit has all three and more…New converter should have a converter clutch that’s at least .045” thick (thicker=better).
Also, I just chatted with my local transmission shop (Hyltons Transmission Service here in Mechanicsville, VA) and he said that he no longer installs the CVC converters because they were just bought out by another nationwide company that doesn't stand behind them the way CVC did. Still the same remanufacturing process though so he thinks they still build a great converter, but he just doesn't want to do business with them any more.
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