On my new to me 252. My bolts sheered off on my right driver sprocket. I just rewelded both my tentioners and tightened the tracks up till the track was just off the 2nd boogie. The tentioners appeared to off been inoperative for quite some time. So the question is Why? Do the bolts thread in from the back side or tack welded in place. I see they have hex heads on them. I tried to drive one out a little force but it didn't budge. luckily my driver lug holes look un scaved, which leads me to believe I sheered them from to tight of track????????