Ugh. Dealin' with this right now. Funny thing is, neither the bolts or the nuts welded to the BS bracket look rusty. Soaked with PB Blaster and they still won't budge. Tapped with a hammer and soaking again as we speak.
Warning - the metal used in the rear bump stop bolts is soft and the heads round easily. Fortunately - so far - the factory nuts welded to the BS bracket and the welds themselves seem solid on mine.
In agreement with Blackoutt about the cussing and alcohol...
The latter not being for the 4R.
$%#^&@!!