2002 SL front seat mount

[Jerry (archive)]

The front seat of my 2002 SL is kind of low for me, so I want to remove two rear bolts that hold the seat in the place, replace them with longer bolts, and have ~1.5" spacers between a car floor and seat mounts. So armed with 8mm socket I tried to unscrew those bolts, but they were so tight that I could only slightly move them about 1/16 of a turn, and then there was a great resistance. I didn't want to break a bolt head nor damage a thread, so I didn't apply a full force, and left it alone. Did anyone do something like that? Any suggestions?
Thank you.

 

[Dan Hicks]

The front seat of my 2002 SL is kind of low for me, so I want to remove two rear bolts that hold the seat in the place, replace them with longer bolts, and have ~1.5" spacers between a car floor and seat mounts. So armed with 8mm socket I tried to unscrew those bolts, but they were so tight that I could only slightly move them about 1/16 of a turn, and then there was a great resistance. I didn't want to break a bolt head nor damage a thread, so I didn't apply a full force, and left it alone. Did anyone do something like that? Any suggestions?
Thank you.

Since they're a critical part of the restraint system, I would suspect that the bolts are somehow special. Certainly they are extra-strong material, and you will need to replace them with ones with a similar rating. And they may be lock-nutted or cottered or some such to keep them from rattling loose.