trailing arms: Goodmark vs. ECE vs. OEM

[SCOTI]

Originally Posted by 69Tom

Question: are 3/4 ton and 1/2 ton 115" wb arms the same length?

Yes. The 3/4 ton arms have plating on top & bottom for gusseting.

[biketopia]

Originally Posted by SCOTI

Yes. The 3/4 ton arms have plating on top & bottom for gusseting.

To prevent flex??

[SCOTI]

Originally Posted by biketopia

To prevent flex??

More for increasing the structural strength is my bet. Since the arms were originally 2 pieces of C-channel butted together & spot welded, they could in theory (reality) come apart. I had one split on my high-school ride in the 80's.... Scared the crap out of me when it happened.

Imagine if it happened under severe duty apps (heavy towing/loads)? The plates added that additional strength/security. The entire arm was not plated, just the top/bottom F/R sections close to the bushings/U-bolts where the flex/twist would be minimal since that's where they're bolted solid to the mounts/rear end.

If I'm upgrading OE arms, I clean between the seams as much as possible w/a wire brush & use air/water pressure to get the funk out. Then I'll do some short 1-1.5" length stitch welds in the horizontal seams about every 6-8 inches of the length. I also weld the vertical seam @ both the front & rear of the arm. Less weight vs. plating & stronger than OE.