Coach's newest trailing arms.



Hey Guys,
Just finished the new upper and lower trailing arms for my GN. Was inspired by DonWG to make my own after he did the same. I researched this with Paul from HR Parts N Stuff before doing it. I used his new 8 sec bushings so I could still have total streetability and no metal to metal contact. I also added HR's rear drag bar to go with these arms.



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These are a few of the new lowers and my new uppers compaired to my Metco's I just removed. Give your opinion if you wish. They are being painted black and installed today.



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Very nice, Coach.
In future lca's, just use one adjusting nut on the tube. No need for two.

One other note. Is the threaded rod threaded into the front uca eyelet completely? If so, I would try to tack the threaded rod into position through the eyelet hole. I'm not sure how welding the threaded rod in the manner that you did will affect the metallurgy, or strength of the threaded rod. That's a pretty critical area. There may be enough strength in the size of the rod that you went with, welded or not. It's just what struck me when I looked at it.

I guess the same would go for the threaded rod welded to the eyelets for the lca's too.
They are tapped and threaded in all the way, about 3/4 of an inch deep. I welded them to avoid them turning when being adjusted. 7/8 RH and LH threads. I debated on putting a 0.2500 pin thru them but elected to thread them instead,for the sthrength. The rod ends are 420 stainless steel and were preheated before welding. They have a .3125 wall thickness so the bushing will have plenty of meat to push against when turning corners. They are greased also. The fittings are not in the pics. The U-shaped pieces for the uppers are all 1/4" 4130 chromoly plate and center piece.They are being painted now.
Thanks for the observations. I know you know your stuff and it helps us both out.

I was just thinking that if the weld was just for keeping the threaded rod from turning, it would be better to tack on the end of the rod through the eyelet hole rather than taking the chance of upsetting the strength of the rod by welding where you did. By no means am I a metallurgy expert on fasteners. I hope I'm just being overly cautious in my observation.
By knowing the type of steel and preheating it before welding, you avoid changing the properties. The guy who welded these does all of our tool and mold micro welding. He checks the rockwell of the steel, before and after, he welds it. I made sure he knew these were criticle areas and that the amount of pull was incredible. He assured me that they lost no structural integrity. He races too and said the last thing he wants is to know his weld is the reason I got FUBAR'd.

Looking good Coach. When you get her on the track tell us if it's an improvement.

They are an improvement already. I kept pushing the metal pin thru the poly bushings on the Metcos. Paul at HR said that is way he designed the harder Delrin bushings he now sells. He said they wont last for ever, but they do take the abuse for quite a while before they need replaced. I will def need this with the new engine I am having built.

Thanks for the compliments, everyone.