3 Link upper Mount Material

[Truck21]

Hello All,

I read and search this site often. Thank you to everyone who contributes.



I am starting to fabricate my offset 3 link and would like to bounce a couple ideas of you.

I am using the mounting points found from Billy Shope's site. I have the Milliken and Carroll Smith books.

I think I've found the materials to use for the shock tabs and lower mounts. 1/4 steel laser cut.

My question is can I use 3x3 .187 wall square tubing for the upper mount? I would also like to mount the panhard bar to the mount so the extra strength seems intelligent.

I have 2.625 forged poly bushings for the 3 link ends They are 3/4 14 thread. I'm going to use Johnny Joints for the panhard bar. I want the least lateral movement.

Also is 1 x .157 wall enough? I was going to use 1.25 x .281 wall if that's not overkill.

I will post pics of the setup when done.

Thanks
Bill

[dontlifttoshift]

1.25" x .120" wall is fine for your link bars. Use weld in bungs for your threads. It's lighter that way.

I prefer 360 degree brackets on the axle housing. You get significantly less warping on the tubes and a significantly stronger connection for your links. Draw them up and have them cut with your shock brackets. .187 material thickness is plenty for all of that. Look at the Detroit Speed quadra link brackets, that's a pretty good design.

I question the effort put in to building an offset 3 link and then mounting the PHB above axle centerline. I consider axle CL to be a maximum roll center height.

[Truck21]

Donny thank you for the reply.

I was planning on starting the panhard bar level with cg. The upper link is going to be set behind the axle by 8 inches. I was going to get slotted brackets so I can adjust the height down the road then weld into place.

I will look up what the 360 brackets are after bowling.

Bowling in the summer sucks.

Thanks!
Bill

[David Pozzi]

Check out the new ridetech R joints

[y5e06]

side question:
would you be willing to share your offset (upper?) mount design and decisions on using specific measurements/locations? What rear end are you using?

[jetmech442]

Donny thank you for the reply.

I was planning on starting the panhard bar level with cg. The upper link is going to be set behind the axle by 8 inches. I was going to get slotted brackets so I can adjust the height down the road then weld into place.

I will look up what the 360 brackets are after bowling.

Bowling in the summer sucks.

Thanks!
Bill

Hey Bill, the height of your upper link pickup points will play a critical role in percent anti-squat. I'm not sure what vehicle your doing this to, but on my 69 cutlass, 8'' back would have been in the trunk floor(and I'm okay with that), but my welder was not comfortable hanging the pickup point so far behind the axle. The longer arm your planning will obviously help reduce pinion angle changes during suspension movement so your on the right track there.

I just completed my custom 3 link last year, and settled on a range of antisquat from 40-160% in ~30 degree increments. there are adjustment holes on the housing side as well as the frame side to accomplish this wide range. I needed to set my car up for autoX, road course and street use, hence the wide range. I understand your desire to use slots on the upper to dial it in and then weld, but it's unlikely you'll get enough surface area to clamp hard enough to keep it in place while you test and tune. Very accurate measurements can yield proper location as well as robustness.

I included a few pics , I hope this info helps, just want to see you succeed.