Tunnel mount bolts
02-17-2011, 01:12 PM
#1
Tunnel mount bolts 95 Z28 w/ TH400 and UMI 2203. The four bolts that hold the mount to the chassis are 8 MM. On this car they pass through the sub frame connectors too. Seems like a small bolt for the size of the bracket. Wondering just what kind of forces are applied to the bracket. I'm guessing the force is almost straight up or down depending on whether the car is accelerating or accelerating. Am I close?
Anyone doing this different?
Al
95 Z28, soon to have an S-60
Anyone doing this different?
Al
95 Z28, soon to have an S-60
02-17-2011, 03:02 PM
#2
Under acceleration, the cross member is forced up into the floorboard so there will likely never be an issue with those forces.
However recently I noticed that the drive side stamped metal bracket was broken off of the floorboard so that is a problem. On deceleration or especially clutch braking, the cross member pulls down on the floorboard so the factory spot welds decided to let go.
I welded the broken bracket back on the bottom of the floorboard but I dont have 100% confidence in this repair so I am going to fab some 14 gage flat brackets to go on top of the floorboard for much greater reinforcement. I will run bolts through the cross member, through the floor and into the fabbed brackets and it should then be plenty strong.
However recently I noticed that the drive side stamped metal bracket was broken off of the floorboard so that is a problem. On deceleration or especially clutch braking, the cross member pulls down on the floorboard so the factory spot welds decided to let go.
I welded the broken bracket back on the bottom of the floorboard but I dont have 100% confidence in this repair so I am going to fab some 14 gage flat brackets to go on top of the floorboard for much greater reinforcement. I will run bolts through the cross member, through the floor and into the fabbed brackets and it should then be plenty strong.
02-17-2011, 05:20 PM
#3
Under acceleration, the cross member is forced up into the floorboard so there will likely never be an issue with those forces.
However recently I noticed that the drive side stamped metal bracket was broken off of the floorboard so that is a problem. On deceleration or especially clutch braking, the cross member pulls down on the floorboard so the factory spot welds decided to let go.
I welded the broken bracket back on the bottom of the floorboard but I dont have 100% confidence in this repair so I am going to fab some 14 gage flat brackets to go on top of the floorboard for much greater reinforcement. I will run bolts through the cross member, through the floor and into the fabbed brackets and it should then be plenty strong.
However recently I noticed that the drive side stamped metal bracket was broken off of the floorboard so that is a problem. On deceleration or especially clutch braking, the cross member pulls down on the floorboard so the factory spot welds decided to let go.
I welded the broken bracket back on the bottom of the floorboard but I dont have 100% confidence in this repair so I am going to fab some 14 gage flat brackets to go on top of the floorboard for much greater reinforcement. I will run bolts through the cross member, through the floor and into the fabbed brackets and it should then be plenty strong.
http://www.rksport.com/main/part_det...mdid=1&catid=3
Al
