TECHLINE

I have a few thoughts and will try to run through them quickly here.

- VERNE SIMONS

RADIUS ARMS OR LINKS?

I live in Nashville, Tennessee, and I'm building my first 4WD. I'm disabled (no wheelchair) and all I have to work with is my '84 E-150 and a Dana 44 TTB out of a '92 F-150. I've widened the engine cross member for clearance and made the center brackets. I've been pulling my hair out over the caster gain caused by a mocked-up (from scrap) radius arm. Two-thirds through the suspension stroke and it's at 10 degrees!?!? I'm sure I don't have to tell you that. So, I'm going to use a parallel four-link instead. I was a machinist, so fabrication is not a problem.

What I need your help with is should I use DOM tubing? Also, the stock radius arms use a 1-inch shaft in the rear, so I was thinking about using two 3/4-inch rod ends front and rear. Would 3/4-inch be sufficient? And what diameter and wall thickness should be used? I have a 302 engine. I really need to get this beast going so I can haul building materials to my site in the Appalachian Mountains and live in it while I work. I hope the helpers show up! Thanks so much for any assistance.

MIKE VIA EMAIL

I have a few thoughts and will try to run through them quickly here. Yeah, radius arms cause a rapid change in caster as the suspension cycles. A gain is noticed on compression and a loss on droop. That's usually not that big of a deal because the suspension should only be in full-droop or full-compression for a short time while driving. And honestly, 10 degrees isn't all that much, assuming you mean 10 degrees back and not forward. I frequently set ride height caster at about 6-7 degrees (with the top of the knuckle laid back) and have had great results.