https://support.oracle.com-->Servise requests tab --> Right side corner you can see support identifier search tab.
Below that tab you can see drop list there you can select SR number and in next tab give your SR number and search.
I tried this but didn't work. Says no information returned.
Do I need special permissions to view hardware SRs?
Yes you need permission on the hardware CSI. Normally Oracle has a know contact for hardware like a Unix sysadmin team.
By default they get the administartion for the hardware CSI. If Oracle is not willing to share the HW CSI you can find it in the Exadata deployment doc created by ACS on delivery.