not enough to hurt nothing on a daily driver. i did this a few times 40 yrs. ago before thay started to make the repair kit, i didn't have a good HB, so it was the only way to get the man going and far as i know it worked out fine. that kit haven't been around for ever. i'm only talking a few hundred thousand. something i did when i had no other choice. dont drive the seal in all the way will work in a pinch also or knock it pass the old place. the first shops i worked in we were 30 miles from a parts store, so we had to make do with what we had.