Weakness in the hamstring relative to the surrounding muscles is quite common. And with lifts like deadlifting, what ends up happening when the hamstrings are not contributing their full input, is that the majority of work is then performed by the back muscles on a short lever versus long lever contraction.
Here is an exercise that I commonly use to help my athletes build strength and endurance in their hamstrings.
Perform the Iso-pulsing contractions in sets of about anywhere between 8-12 reps. You will likely spasm around 7-8 ☺ when you first start out. Do about 3-4 sets worked in with your regular training about 2 times a week or alternatively you can do one set every day.
You will feel the difference in your performance while gaining that performance with less aches and pains. Give it a try and let me know how it goes.