I never had problems before doing them, but I started to notice not so desireable traits in my elbows recently.
My injury background:
I had tennis elbow in my left elbow from upping the weight, but I solved that by cutting the weight used and rest. However, I know have golfers elbow in the right elbow. I don't believe it was soley attributed to pullups at all, because of was mimmicking a serve motion in tennis in between sets, and the next set I felt a tweak in the position. Now, I can't do a single full pullup without pain in the top position. I can still do sets of reps, and it hurts less with each set, but that is still bad. Anyway, I cut my frequency from 3x a week to 2x a week for two weeks. Due to it still hurting on the first set, I dropped my frequency to once a week this week. After 7 days rest, still pain. I quit after one set. So, currently, I will do another session next Friday, and see how I feel.
Besides the pain:
My left elbow joint rubs when close to the top position when flexed and extended.
My right elbow seems to have the slightest rub sometimes in the suppinated position only. It is tough to detect, but I can feel it on sometimes.
I don't want to wear my elbows down to where I can't maintain my fitness improvements, and enjoy exercise in my later years. I read article talking about shearing forces with a fixed bar. So, now I wonder if I should switch to ring pullups only.