MTFCA Forum

Hey guys. I'm looking to make a lowering setup like the one pictured but need to make a threaded rod. I can't find a long enough bolt so I was planning to have threads rolled on each end of a 9/16 rod to pass through the perch and custom shackle. I was wondering what if any specific steel you guy would recommend.

Thanks!

Shane a 5/8 bolt grade 8 machined down is the way I have done in in the past. Don’t forget to put your ring gear on the other side of the housing, a lot of reverse options and limit forwards!

Hank

Hey Hank thank you. I searched 9/16 bolts and everything over 6" long seems to be on intergalactic back order. I think to span the gap from the perch to the radius rod I would need a little under 10" although I haven't taken a real measurement yet. Just checked to see if the 6" bolt would work and it came up far too short. Fastenal has some listed but once added to the cart they state that there's none in existence. I'll look at 5/8 options and see if I can find someone to turn them down.

9/16” are now very specialized, so taking 5/8” extra long shanks are the way to get around the issue. I like the larger head anyway with suspension for attachment displacement.

Hank

Grainger's website shows 5/8" x 10" bolts in UNF, UNC and various grades.

Thanks guys. yeah it seems 5/8 is much more readily available. That seems like the solution to my problem.

Shane, I would not mount the forward end of the rod to the radius rods in the manner you have. All radius rods are prone to internal rust, especially the later split seam ones, and the worst rust is at the downhill end at the rear. The bolt hole drilled through the rod at that point only compounds the problem. A better solution may be to fabricate a bracket which clamps around the radius rod at that point. This will add strength rather than weaken it. Others may have a different take on it.

Allan from down under.

Hey Allan I was thinking the same thing. I was going to make something that hooked over and clamped with a bolt under the radius rod so it's a tight fit in all directions. I just liked the general idea of the one I posted.

1045 Steel carbon might be a choice, then maybe have it surface hardened. MY OP; I would stay away form drill rod, might be easy to single point, not easy using a die. I was thinking today about having a bolt go thru the radius rods and decided...NOT! Good idea on the "J" bracket going over it.

Don’t forget to put your ring gear on the other side of the housing, a lot of reverse options and limit forwards!

My Grandpa told me his first hand story of lowering his first speedster by flipping the rear end over. He didn't swap the ring gear and backed into the side of my Great Grandpa's brand new Studebaker when he hit the low speed pedal.

Kim R. Wynn

Shane 4140 tool steel is what I would use,machines nicely and is a strong tough steel but not hard and brittle cheers pete

I like the set-up shown for lowering the rear of the car. As for the rear radius rod being weak...if you look at the way a radius rod is made, it seems to have some real strength in this area. There is a roughly 1/4" thick bar that is split to form the two legs or the radius rod. The radius rod tube is also split and the "Y" shaped 1/4" bar is inserted into the tube then it is brazed or welded (don't remember which) into the tube. So, I believe in the area where the bolt is shown going through may be about in the middle of the 1/4" bar. I found out about that 1/4" bar when I just cut, removed, and welded the tube back together (several inches forward of where the bolt is sown here) when I installed a Warford years ago. The weld I made broke. That is when I discovered there was a solid bar (the 1/4" "Y") that I should have welded the tube to. I did that and have had no more problems.
Verne Shirk
Wichita, KS