How do you tune torque converter clutch lockup?
Tune lockup in Transmission > Auto TCC: the TCC Apply/Release Speed tables set the MPH-vs-TPS lock and unlock points per gear and mode, and the TCC Duty Cycle Max/Min tables set how hard the clutch applies — 100 max / 90 min is the common setting for aftermarket converters. Disable wide-open-throttle lockup unless the converter is built for it, and never enable TCC Lock During Shift: it stays locked through the shift and destroys the clutch lining.
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Who this applies to
- Computers: P01, P59, E38, E67
- Engines: LM7, LQ4, LQ9, LS1, LS2, LS3
- Transmissions: 4L60E, 4L65E, 4L80E
- Years: 1999-2013
- Not for: 6L80E/6L90E (T43 TCM — different TCC strategy)
Part-throttle lockup schedule
- Keep release speeds below apply speeds so the clutch doesn't cycle at the boundary. release < apply
- Fix the speedometer/gear-tire calibration first — every TCC table indexes off MPH.
Clutch apply firmness (duty cycle)
- Auto TCC > TCC Duty Cycle > Maximum/Minimum: for an aftermarket converter use Max 100 / Min 90 for a solid, low-slip lockup.
- Leave stock or softer values on a stock converter and daily driver — full duty hits like another gear.
Wide-open-throttle lockup
- In the Full Throttle apply/release tables, put the max value (318) in all apply cells and 317 in release to disable WOT lockup on street single-disc converters. apply 318, release 317
- Only enable WOT lockup on multi-disk converters built for it — it can be worth trap speed, but it kills single-disc clutches.
Never do this
- Leave TCC Lock During Shift disabled — it keeps the clutch locked through the shift and destroys the lining.
Careful
- Never enable TCC Lock During Shift — expect broken parts.
- Don't lock a stock or single-disc street converter at WOT; locking through 3rd or 4th flat out with a converter not designed for it is asking for a blown converter.
More in transmission tuning, or build a checklist for your swap with the tune checklist tool.
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Check this first
- Log TCC Slip RPM, TCC Mode, and current gear on a steady cruise: slip that won't drop near zero with lockup commanded points at the tune; slip with full duty commanded points at the clutch.
- Confirm the speedometer is right first — wrong MPH input corrupts every TCC apply/release decision.
Try this, then this
- Correct the speedometer/gear-tire calibration. — All TCC scheduling is MPH-based. Worked if: Scanner speed matches GPS.
- Set a sane apply/release schedule per gear with release below apply. — Stops hunting and sets when the clutch actually engages. Worked if: Lockup engages once and holds.
- Raise duty cycle toward 100 max / 90 min if it slips on apply. — More apply pressure means less slip and less clutch wear. Worked if: Slip RPM drops to near zero.
- Disable WOT lockup for street single-disc converters. — WOT lockup on a converter not built for it destroys the clutch and sends debris through the trans. Worked if: No slip codes, no shudder at WOT.
- If it still slips with 100% duty commanded, the clutch is mechanically worn — replace the converter. — No table fixes a worn clutch. Worked if: The new converter holds at stock duty.
How you know it's fixed
- TCC Slip RPM drops to near zero when lockup is commanded and stays there.
- No lock/unlock cycling at steady cruise; apply feels like a clean extra shift, not a shudder.
Key numbers
| What | Value |
|---|---|
| What the apply/release tables control | lock/unlock speed vs TPS and gear |
| Lock-during-shift warning | do not enable |
| Aftermarket-converter duty cycle | Max 100 / Min 90 |
| Disable value for WOT apply tables | 318 apply / 317 release |
| WOT lockup payoff on a converter built for it | up to 2 mph and 0.2 sec in the 1/4 mile |
Every option we know of
| Maker / product | Part # | Fits | Price | Where | Status / notes |
|---|---|---|---|---|---|
| Circle D Specialties multi-disk lockup torque converter (built to order) | 4L60E/4L80E; specify WOT-lockup use when ordering | direct / dealers | Small batch built converters need matching duty-cycle tuning |
Prices are approximate as of September 2026. We list every option we know of, including small shops and used parts we can't link to. Confirm fitment with the seller.
Time and cost: Tuning time only; a converter built for WOT lockup is the expensive fix.
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