Fiero Tips and Tricks

Battery Box Replacement

Have you ever looked under that battery to see the condition of the battery tray?  Also the insulation under the battery tray is the perfect place for rust to start.  This is the one area I think the Fiero engineer could have done a better job or come up with a better idea.  You have an open vent above the battery, rain or washing the car allows (along with the owner before you who let the battery start to leak and did not notice) the acid to run down on the tray and through the insulation and starts to eat away at the metal area.



I should have taken a picture of what I started with (there was not very much) but here was a piece that I cut out.  This project took me a day and a half.  A die grinder and a Dermul tool help greatly to remove the spot welds.



I started by cutting out part of the old tray to get some working room.  Use a razor blade to remove the insulation (do this neatly, it will be put back in when the job is completed).  On the front bracket I cut it off about one and one half from the forward wall.  This gives you double thickness of metal to attach the new tray to.




On the side panel you will find four spot welds, at the rear there are three spot.  This is the hardest part of this project.  Carefully grinding out the old spot welds just enough to break them loose.



When the battery tray is out, clean out as much rust as you can.  I recommend you trial fit the new tray and drill the new holes for mounting.  I prefer to use #8-3/8 sheet metal screws, pop rivets can also be used.



I recommend using Por 15 product to prevent the rust from returning.  This product can be found on the web.  If you have any small holes that need to fill in, you can use some fiber glass cloth and the Por 15 as a resin.  After the Por 15 dries, mount the battery tray and install the insulation.  I put the front and side insulation pieces back in but left the piece directly under the battery out.  I bought my battery tray and the heat shield through the Fiero Store.