I wrote a note to Scott. Here it is and his response.
Scott,
Sorry to show my ignorance here. In some pictures of the crossmember, you have a metal tube where the bushing for the lower a-arm will be. What is that?
You describe the lower a-arm being bolted in. Assuming I buy the Global West arms and they use ½ inch bolts, do I just buy 4 bolts long enough to fit?
I would presume it best to buy grade 8 bolts. I have thought about bolts from Totally stainless. They sell grade 8 I believe. Is it a bad idea to use stainless?
Would you use nuts and lock washers or nylock nuts?
Is it possible to over tighten the bolts and pinch the bearing on the lower a-arm? Your cross member is pretty strong looking or do the bushings come with a metal sleeve in them that will bear the force of the tightened bolt?
Thanks for any help.
Todd
The metal tube was a spacer used to weld up the first prototype as we (myself and fab shop) were working on ways to weld the cross member both in the jig as well as the areas after we pulled it out of the jig.
I would check with Global West on the diameter and length. They may even supply the bolts
I have never found a grade 8 stainless. I would stay away from stainless. If you are worried about corrosion, I can point you in a few directions for “ultra coated” That is what the military uses. They are available thru Fastenal and McMaster Carr. However GM uses standard Black Oxide fasteners which last many many years and miles for a daily driven vehicle. They should last another 60 years on a ‘bolt. I would recommend Flanged head bolts to match the Prevailing Torque Nuts. am including a few images from McMaster for reference Again, these are what GM used.
Prevailing torque lock nuts are required on suspension parts – available at any hardware supply. That is what is stock from GM. Nylocks may come loose.
No, the lower bushing has an inner sleeve that you tighten down on. The sleeve then remains fixed to the cross member and the bushing actually rotates on the inner sleeve. This is true with stock rubber, urethane, delrin, etc.
BTW, I did order A-arms from Global West. In talking to them, they use 12mm bolts, so hopefully they will bolt right in.
