Narrative:

While cruising at FL350 approximately 90 miles west of ZZZ the le flaps transit light illuminated along with an amber in-transit light for the number five leading edge slat. Initially it appeared to be a false indication as the slat appeared visually to be fully retracted. While [we were] reviewing the QRH the control yoke began to turn slowly toward the right; reaching three to three and on half units deflection. The autopilot was then disconnected and the yoke displacement required to hold wings level remained the same. Completed QRH and informed ATC that we were declaring and emergency and needed immediate descent clearance with a diversion to ZZZ. Informed the flight attendants of the situation and that we would be making a precautionary landing; then briefed the passengers. During the later part of the descent the yoke displacement required began to lessen as speed and altitude decreased. After briefing the approach and QRH checklist for a flaps 15 landing; we went over the overweight landing checklist in the QRH. At this point I decided to configure for landing; approaching downwind leg; for a controllability check. That's when we noticed that both lights had gone out and now all indications were normal. Landing was uneventful but due to the overweight landing; I had the fire department check for hot brakes; which was negative; so we proceeded to the gate.

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Original NASA ASRS Text

Title: A B737-300 LE Transit Light at FL350 indication was initially thought to be false until the autopilot rolled in right aileron to compensate. Once this occurred the crew elected to divert to a suitable alternate airport. Prior to landing all LE Flap anomalies disappeared.

Narrative: While cruising at FL350 approximately 90 miles west of ZZZ the LE Flaps Transit light illuminated along with an amber in-transit light for the number five leading edge slat. Initially it appeared to be a false indication as the slat appeared visually to be fully retracted. While [we were] reviewing the QRH the control yoke began to turn slowly toward the right; reaching three to three and on half units deflection. The autopilot was then disconnected and the yoke displacement required to hold wings level remained the same. Completed QRH and informed ATC that we were declaring and emergency and needed immediate descent clearance with a diversion to ZZZ. Informed the Flight Attendants of the situation and that we would be making a precautionary landing; then briefed the passengers. During the later part of the descent the yoke displacement required began to lessen as speed and altitude decreased. After briefing the approach and QRH checklist for a flaps 15 landing; we went over the overweight landing checklist in the QRH. At this point I decided to configure for landing; approaching downwind leg; for a controllability check. That's when we noticed that both lights had gone out and now all indications were normal. Landing was uneventful but due to the overweight landing; I had the Fire Department check for hot brakes; which was negative; so we proceeded to the gate.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.