B737-700
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 222; Flight Crew Type 13000
Aircraft Equipment Problem Less Severe
Flight Crew Diverted; Flight Crew Landed As Precaution; General Maintenance Action
Aircraft
On takeoff roll at approximately 130 knots; aircraft abruptly pulled to the left twice in rapid succession causing an alarmed expression from the First Officer (FO) (Pilot Flying).  I noticed the nose track abruptly left twice; but without my hands on the controls did not notice any jolt. After climbing to a low workload flight condition; the FO indicated that he felt a jolt to the left twice like nothing he had felt before in a Boeing. I then remembered that on the previous leg I had a similar jolt to the left; at about 130 knots [on departure]. I had noted this to the FO at the time; but attributed it to wake turbulence. But thinking back; the only aircraft in the pattern was an Air Force T-1. We established a patch to Dispatch and discussed the situation with [Dispatch] and Maintenance. We made a collective decision to divert to have Maintenance check over the aircraft.
During takeoff roll; the aircraft shimmied left twice at around 100 knots and 130 knots. The shimmy felt like there was something wrong with the nose wheel steering.
A B737-700 flight crew reported they noticed an abnormal 'shimmy' on the takeoff roll that might have been nosewheel steering related. They diverted to an alternate for maintenance.