iv'e ran them for the last 8 years and haven't had any probs, still running the same constant load coils i fitted 8 years ago and have had a tjm bullbar and hydraulic winch with a steel cable, i just recently changed the front struts to the foam cell pro and they are much better than the normal foam or gas struts, my d40's live in the bush from getting firewood and 4wdriving and i think there good value for money.