Weak '86 Tri-Z Swingarms ??

[Tri-Z 700]

I'm running an '86 swingarm on my '85 Tri-Z, and I noticed there is a hairline crack starting to form near where the rear shock support brackets are welded on. My buddy has an '86 swingarm on his Z too, and his is splitting in the same spot. I've never seen the '85 swingarm split like this. Was this a flaw with the '86 design? Should I weld up the '86 and keep running it, or should I replace it with an '85?

[Bryan Raffa]

yes I think the 86 were prone to crack,..I weld mine and forget about it..

and I also think the 85's were stronger,, I have cracked one ... but there less prone

[Tri-Z 700]

Thanks, I have a '85 swingarm lying around I could use, but I was using the '86 beacause I'm running a Raptor 660 rear shock, and it seemed the '86 swingarm kicked the bottom of the shock rearward just a little, and I needed all the clearance I could get for the shock.

[Mosh]

The 85 Swingers only cracked in front of the shock, in the center cossbrace.
I have never seen a 85 cracked near the shock mount.
The 86 was redesigned with beefier supports at the shock mount.
Odd they would crack there with more gussets.
If you do go to a 85 swinger, they take different pivot bearings and bushings than the 86.