Hello folks,

I did a search and could not find anything on 3 links. It seems like the 3 link would be a better choice for a street or track car because it doesn't bind in roll. Why is it that no one seems to be building them? Am I missing something?

I am thinking of building one by adding a hump to the trans tunnel and turning it into an armrest for the rear passengers. I have very little experience with suspensions on solid axle cars, so please let me know if there is a reason why this might not work properly.

Thanks...

Buy the book Chassis Engineering by Herb Adams. Lots of info on suspensions and very practical stuff too.
I'd imagine you could use the front spring attachments for the lower links, leaving just the upper link bracket to make.

One problem is where on the rear axle to attach the upper link?

The angles of the links is critical to the proper function of the rear suspension.
Adams outlines this.
David

Thanks Mr. Pozzi,

That is exactly what I was thinking for the lower links. I need to look at the angles and make a mounts that attach to the axle at the leaf spring locations.

For the upper attachment to the rear end, I think there is at least one boss on top that could be threaded plus the bolts on the back side for the cover. I would have to make a fairly complicated bracket to distribute the loads across the top 4 cover bolts and the boss on top. If none of that seems like it will work, I know someone who is an excellent welder (teaches welding at the local tech college), and might be able to weld something to the cast iron as a last resort. I will have to read up on this because I am not familiar with the strength of cast iron welds. Fortunately, I beleive the loads on the upper link are not as large as those for the bottom links, but then again there will be only one upper link. I'm working on computer model of the car that should give me decent estimates of the loads involved for launch and also help me determine the optimum angle for the upper link.

I already have Herb's book and I was fortunate enough to work on a project with him once when he was with SLP (not sure if he is still there, it has been 4 years). It has been a while since I looked at it, so I'll review it.

Thanks, it is very generous of you to give so much of your time to help those of us with less experience.

TireMan,

Just a thought? how about the top third link being a "Y". Weld brackets to axel tubes and fab up a bracket/brace in the trunk/tranny tunnel ? Just an idea. smile.gif

Doug,

I think the top link needs to only have one pivot at each end. I am afraid if it has a Y configuration with two pivots on the axle side, then it will bind in roll when the bottom two links induce their roll steer. Maybe with rubber bushings, this would be negligable, but deserves some thought. At the very worst, I could create a bracket that welds to the axle tubes on each side for the center pivot over the top of the pumpkin.

Thanks...

I saw a three link design before using a 9" ford rear, where the guy added longer studs to where the 3rd member bolts to the housing. Then he bolted the bracket that holds the upper control arm to these longer studs. It had to be off-set to the right some to clear the pinion, so I'm not sure if that would make a difference or not in handling. There is a picture of it on one of the last pages of the current "Street Rodder" magazine if you get that mag.

It might be easier to do a torque arm like the third gen Camaros have. You just need the two lower links and a torque arm running forward along one side of the driveshaft.
If the front pivot of the arm is high enough you could get good weight transfer out of it.

I think Adams gives a height of the three link upper pivot that is minimum. Anything shorter will cause rapid wear of the upper link.
David