Well here is a look at a cracked frame on a 1994 F-150.
We tried to fix it however if your frame looks like this, your not doing so well! This caused a SERIOUS sudden jeark to the right. The entire frame rail would tweek when turning the wheel from side to side. REAL NASTY.
You could not tell the extent of the crack until after we got everything out of the way. An order come in for the motor so we cut this truck up.
More than once (hell.. more than 5 times) I've had to repair broken welds on the #2 crossmember on Chevs... The K2500s loved to break on the left side. This would be back in the early 90s on trucks a lot "newer" than this. I can even recall a similar occurance on a Dodge one ton... a late 80s truck...
And we wont talk about the rear control arms on Tercels rusting out...