I made a rear shock tower brace for my car(’87 325). It’s a fairly simple part to make if you have some basic fabricating and welding skills, so I thought I would pass the steps and a pattern to make the mounting brackets.
Some pictures
http://www.imagestation.com/album/?id=2101971462
Materials:
1/8” thick steel plate
1” square steel tube, 0.06” wall thickness
The first step is to print two copies of the drawing and cut out the mounting bracket patterns. There are two lines 3” lines on the drawing to check if your printer is printing at the correct scale. If it is not, some printers have X and Y scales that can be edited to get a correct print out. The two brackets are the same, you flip one over to get the opposite side. Glue the two patterns to the 1/8” plate. I used a 3M spray adhesive. Once it dries punch the centers of the three holes on each bracket. It’s better to do this first in case the paper comes off at some point. Then cut the along the edge of the line. I used a band saw, which is probably the best bet as it cuts pretty square and doesn’t tend to rip the paper off like other tools. You could also use an angle grinder, a reciprocating saw, jig saw, hack saw, etc. You might want to scribe/draw the outline of the bracket if you use the use one of these in case the paper comes off. After cutting the outline, drill the three holes. Two are 3/8” (9.5mm)holes. The shock mount studs are 8mm, but the extra large hole help make up for any location errors. The big 2”(50.8mm) center hole is clearance for the shock bushing. A 47mm hole would clear, but is an odd size. I used a 2” hole saw. Hole saws often cut as much 1/8” oversize, but I have found that Lenox makes ones that cut quite close to size. I filed and sanded the edges to de-burr and remove cutting marks.
I then bolted both brackets onto the shock mounts in the car. I cut the steel tube to 38.5 inches in length (you will want to double check this with your car), and put it in the car on the two brackets, lined up with the rear edge. The two brackets are angled slightly down to the middle of the car, but I did not feel that the gap between the end of the bracket and the tube was enough to worry about fitting/ bending the parts together. II used a vice grips to as an end stop to keep the bar from sliding back. I centered the bar up on the two brackets. I used cardboard to try and keep weld spatter from getting on the car. I also undid the battery ground as the electric welders could possibly damage the ECU and other electronics. I am not sure if this is actually necessary, but am not willing to take the chance. Then I tack welded the brackets to the bar. I took the bar out of the car, and welded the rest of the joints between the brackets and the bar. I then rechecked that it still fit the car.
The fit of the brackets on the outside to the fender wells is quite tight, but the other three sides of the brackets are pretty much wide open if you want to modify the design. Let me know if you want a PDF drawing of the bracket.
Nic
Some pictures
http://www.imagestation.com/album/?id=2101971462
Materials:
1/8” thick steel plate
1” square steel tube, 0.06” wall thickness
The first step is to print two copies of the drawing and cut out the mounting bracket patterns. There are two lines 3” lines on the drawing to check if your printer is printing at the correct scale. If it is not, some printers have X and Y scales that can be edited to get a correct print out. The two brackets are the same, you flip one over to get the opposite side. Glue the two patterns to the 1/8” plate. I used a 3M spray adhesive. Once it dries punch the centers of the three holes on each bracket. It’s better to do this first in case the paper comes off at some point. Then cut the along the edge of the line. I used a band saw, which is probably the best bet as it cuts pretty square and doesn’t tend to rip the paper off like other tools. You could also use an angle grinder, a reciprocating saw, jig saw, hack saw, etc. You might want to scribe/draw the outline of the bracket if you use the use one of these in case the paper comes off. After cutting the outline, drill the three holes. Two are 3/8” (9.5mm)holes. The shock mount studs are 8mm, but the extra large hole help make up for any location errors. The big 2”(50.8mm) center hole is clearance for the shock bushing. A 47mm hole would clear, but is an odd size. I used a 2” hole saw. Hole saws often cut as much 1/8” oversize, but I have found that Lenox makes ones that cut quite close to size. I filed and sanded the edges to de-burr and remove cutting marks.
I then bolted both brackets onto the shock mounts in the car. I cut the steel tube to 38.5 inches in length (you will want to double check this with your car), and put it in the car on the two brackets, lined up with the rear edge. The two brackets are angled slightly down to the middle of the car, but I did not feel that the gap between the end of the bracket and the tube was enough to worry about fitting/ bending the parts together. II used a vice grips to as an end stop to keep the bar from sliding back. I centered the bar up on the two brackets. I used cardboard to try and keep weld spatter from getting on the car. I also undid the battery ground as the electric welders could possibly damage the ECU and other electronics. I am not sure if this is actually necessary, but am not willing to take the chance. Then I tack welded the brackets to the bar. I took the bar out of the car, and welded the rest of the joints between the brackets and the bar. I then rechecked that it still fit the car.
The fit of the brackets on the outside to the fender wells is quite tight, but the other three sides of the brackets are pretty much wide open if you want to modify the design. Let me know if you want a PDF drawing of the bracket.
Nic
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