Anyone ever had a crack in the rear frame bracing?
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750H.P.V6
Brutal 6 Racing
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- Sep 4, 2001
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My old car had a crack in a similar place. The car hadn't been in any accidents however I did drag race it quite a bit. I kept an eye on it and the crack didn't seem to grow so I can't say for sure what the cause was.
Nea
Nea
A friend brought his 84 T over and it had cracked in the exact same area. His car had the small support plated behind it. I noticed a couple of my 84's had the same small plate but those cars were not raced until I got them. The 85's I had had a wider plate as does my 87. My 87 gets raced and I have not noticed any cracking as of yet.
Looks like I have a large plate behind and then there are one on each side welded inside diagonally. I wonder if wheel hop, would cause the crack? Probably bad springs and shocks wouldn't help either. I've never tore one of these down this far, so I was kinda curious if this is a known problem area.
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- May 26, 2001
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These G Body frames do NOT hold up well under performance conditions, especially drag racing - either strip or street. 
We do lots of mods to reinforce the frame, and one is to weld a bar between the frame rails just behind that frame brace.
We do lots of mods to reinforce the frame, and one is to weld a bar between the frame rails just behind that frame brace.
These G Body frames do NOT hold up well under performance conditions, especially drag racing - either strip or street.
We do lots of mods to reinforce the frame, and one is to weld a bar between the frame rails just behind that frame brace.
What size bar and exactly where do you weld in. I'd rather not have to worry about it cracking again.
Master series silver (rust primer) and ag111 top coat satin black. I bought 2 of the kits they offer(2 quarts of each). I had enough to do the whole under side of the body, the inside floor pans, the entire frame, and the complete rear end. The top coat is uv stable. I sprayed it on and it is some awesome stuff.
The MasterSeries Coating Line By PM Industries: Headquarters of MasterSeries Rust Preventive Paints and Coatings For Less - Get Rid Of the Pits!
Here are some pics:biggrin:
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turbofabricator
Well-Known Member
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- Mar 7, 2004
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They interfere with some exhaust systems. Have to check your particular system, but they should help.
Probably too late now, but you should have welded the front cross member hole shut (so you don't lose a socket in there), boxed the frame rails and also narrowed the rear frame near the tires for more room. Boxing the frame rails is pretty simple using 3.5" X .190" bar stock and some gussets. I'm currently doing that right now and will post pics some day soon. I am also going to add a cross bar as soon as I get the engine/exhaust installed to check for clearance. It will have the three muffler system and room is at a premium behind the rear cross member.
Probably too late now, but you should have welded the front cross member hole shut (so you don't lose a socket in there), boxed the frame rails and also narrowed the rear frame near the tires for more room. Boxing the frame rails is pretty simple using 3.5" X .190" bar stock and some gussets. I'm currently doing that right now and will post pics some day soon. I am also going to add a cross bar as soon as I get the engine/exhaust installed to check for clearance. It will have the three muffler system and room is at a premium behind the rear cross member.
My frame is still the same as pictured. I'm doing lower ball joints now
I hate doing them, but can't overlook that part if I have gone this far already.I'm looking foward to some pics from you Ken.:biggrin: Send me a link when you start posting the info please.
Squid4life
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- Jul 5, 2004
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- 6,275
Mine had a crack clear through that cross frame support. When you lifted the body off to do bushings you could grab the ends of the frame in the rear and move them around like they were completely separate from each other. Mine had a pinion snubber on it at one point, and I think it was very low, so put those together and something bad is bound to happen. I got a piece of another frame and opened the ends up just a tad, then welded it over my cross support. Basically the frame is doubled up in that center 18" or so. I assumed I was the only one with this issue!
At that point, the rear lower control arms are pushing on the frame and the rear upper control arms are pulling backwards on the cross support - the rear axle is trying to lift the front of the car. Often times the traction is not equal from left to right, as the axle is also rotating, forcing one tire down and lifting the other. It's all those forces together that can tear the cross support.
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