The truck was carrying a digger when it struck the rail overbridge and toppled over.
Train services are mostly back to normal following a "network control" issue that shut down Auckland's network today.
Auckland Transport earlier said trains across the city were delayed or cancelled, with no news on when the service would resume.
It is the second suspension of services this morning.
Trains across the network are delayed or cancelled due to a Network Control matter. It is unknown when normal service will resume. Updates to follow. pic.twitter.com/MuRHNq3hYw
Earlier today a truck that crashed into a rail overbridge in New Lynn forced the suspension of all trains on the Western line for two hours.
All trains were cancelled or delayed, Auckland Transport tweeted, as trains could not run over the bridge until it was inspected after the 8am crash.
Rail services were restored just before 10am but delays were expected to continue.
Clearance has been received and recovery is in progress. Please continue to expect some disruption as normal service resumes. Thank you for your patience and understanding. https://t.co/8zmjDsj5aK
The truck, which was carrying a digger, ended up on its side. It is still at the scene with a heavy haulage vehicle on the way to remove it.
A rail shuttle is currently operating between Swanson and Henderson and vice versa, so customers can connect to scheduled bus services at Henderson. https://t.co/feyt2wuv5w
"If you are travelling into the city from the west, multiple bus services depart New Lynn into the city," AT said.
"The 18 bus runs every 6 minutes along Great North Road, and the 22 along New North Road."
If you are travelling into the city from the West, multiple bus services depart New Lynn into the city. The 18 bus runs every 6 minutes along Great North Road, and the 22 along New North Road. https://t.co/feyt2wuv5w
Scheduled buses are accepting all train tickets and AT HOP cards.
In 2017 a 10-wheeler truck hit the same overbridge and flipped on its side, also bringing trains to a halt.
Due to a truck hitting a rail over bridge near New Lynn, all trains are currently cancelled or delayed on the Western Line. Trains can not run over the bridge until it is inspected. Scheduled buses are accepting all train tickets and AT HOP cards. pic.twitter.com/leSViy8l8b
Due to this truck hitting a rail bridge, train services on the Western Line are currently halted. Please expect delays and cancellations. We will have more information shortly. https://t.co/wd3QMKYHpO