Unable to keep to the schedule while Boeing turned out 747s which therefore had to have concrete blocks hung on the pylons while Pratt did their best to catch up, the JT9 clearly suffered from the rush, as well as having to be financed from company (United Technologies) funds.
About the same time, Douglas was having similar delivery delays with DC-9 components - landing gear, IIRC
Meanwhile, Boeing too was bleeding money, resulting in the famous 50% workforce cut, and even so nearly went under.
...But that was partly due to the
B-2707 SST cancellation.