Two Link Suspension Questions

[Ratcrazy]

I am thinking about running a 2 link suspension from a late 60's to early 70's Chevy truck. What are the pros and cons of a setup like this?

The car will only weight about 2200 lbs when finished. Engine is a stock 230cid straight six with a powerglide so there is not alot of torque. Rearend is a 9" Ford with a 3.25 gear.

The radius arms will be mounted solid to the rear axle with a panhard bar to center it and setting on coils. The front of the arms will be at an angle in the front toward the center of the chassis, similar to a wishbone setup but not as close.

I have been told not to run the radius arms in a straight angle/line off the rear end like ladder bars for this would not allow for articulation.

How much articulation will be needed in the rearend and will this setup supply what is needed.

Any pictures of this kind of set up and suggesting would be appreciated.

Thanks and God bless

Larry

 

[Flipper_1938]

In order for them to work right, the fronts need to be mounted close together.

 

[Ratcrazy]

How close is close together? Close as in touching or some spacing between them like maybe a couple of inches.......more?? less??

Thanks for your reply

Larry

 

[Gastrick]

Just angled in as much as possible, on either side of the driveshaft at the front would be best. They don't need to touch.

Something like this would be propper

 

[Ratcrazy]

Thats exactly what I needed to see and hear. This is the set up I am looking for. One more question about this set up, does it ride and handle as good as the old late 60's-
70's trucks?

Thanks for the photo and the info.

Larry

 

[bob w]

I put truck arms and Corvair front coil springs in the rear of a '31 Model A sedan 25 years ago. The owner is still driving it without any changes or problems.
While I agree that is the best 2 link geometry, I have done a parallel 2 link recently and it works well. I used large thick, soft rubber bushings (some surplus upper A arm bushings) at the front of the links which allows the necessary movement.

 

[Ratcrazy]

Thanks Bob, another question. Can truck arms be cut and welded back together again? This is only about 3 feet between my rearend and my transmission crossmember. 100 inch wheelbase. short lil rascal..

Here's a couple of photos of the chassis.
The bar in front of the rearend will be removed when attaching the rear suspension. Its just there for support and squaring the frame when I welded it up.

Any suggestings or comments would be welcomed and appreciated.

thanks
Larry

 

[bob w]

http://ratrodsrule.com/forum/showthread.php?t=3030
A friend built this coupe. You can see how he did the arms from scratch. This car is street driven and has gone mid 11's at the strip.

 

[Ratcrazy]

Can you give me the diameter of the tubing used to make the bars? Looks to be 2x2x(wall size)? Also what size bolts and bushings (what to order or ask for at the local auto parts store) was used on the front of the bars?

After seeing this build it pretty much answers alot of my questions as to how and what to build. I do appreciate this info. It does help alot and that ride is awesome.

Would it be possible for me to write to your friend to pick his brain a little on some more unanswered questions? With his permission only. If so please e-mail me his address.

Thanks again Bob for this help and God bless
Larry

 

[bob w]

You can send a PM to him. He is "tator" on this site. I'll send him an email, in case he doesn't visit here soon.

 

[Ratcrazy]

Thanks again Bob

 

[Flipper_1938]

Don't use tubing to make the links, it can't twist like the GM truck arms do. It needs to be an I-beam. Rigid links will cause something to fatigue and break.

I have seen people make their own I-beams by slicing the tubing down the middle and then put the newly made c-channels back-to-back and welded into an I-beam.

Longer links work best. If you don't have the room, 4 link it.

 

[tator]

The 2 link suspension Bob W showed on the 31 Chev uses 78-79 monty carlo front bushings for the trailing arms, they pound in tight in 2 in exhaust pipe welded in the front . It takes 1/2 in bolts. Tubing is 2 x 3 3/16 with 3/4 to 0 slot cut out of the center welded back together, makes them tapered for looks. Rear has two steel slugs welded in up and down with 5/8 bolts, bolted to saddle welded to rear end. Saddle is 2 x 4 3/16 tubing with a 3 in. hole drilled in center, then cut in 1/2 down the center. Keep the bars 30 in long or more, too short of bar will cause the rear end to travel in an arch and upset the drive shaft angle. Add pan hard bar and you are done. When these bars are installed, level with the ground is best. Tator

 

[Ratcrazy]

Thanks for the reply Tator.

Also thanks Flipper for your reply.

 

[Ratcrazy]

The 2 link suspension Bob W showed on the 31 Chev uses 78-79 monty carlo front bushings for the trailing arms, they pound in tight in 2 in exhaust pipe welded in the front . It takes 1/2 in bolts. Tubing is 2 x 3 3/16 with 3/4 to 0 slot cut out of the center welded back together, makes them tapered for looks. Rear has two steel slugs welded in up and down with 5/8 bolts, bolted to saddle welded to rear end. Saddle is 2 x 4 3/16 tubing with a 3 in. hole drilled in center, then cut in 1/2 down the center. Keep the bars 30 in long or more, too short of bar will cause the rear end to travel in an arch and upset the drive shaft angle. Add pan hard bar and you are done. When these bars are installed, level with the ground is best. Tator

Started building the trailing arms today. Here's what I have so far. I decided not to do the split like tator did on his but will cap the ends of the arms and sharp them in to meet the profile of the bushing sleeves. Total cost on these arms is $70.00. Not bad for new arms. I really like these because they can be removed if something ever happens to them.

Good design Tator and thanks again for your help here.

 

[rainman]

Bob that coup has a set-up very much like my truck I used 2x2 box and cut the front eyes off some leaf springs welded them in the box. I've always heard you need to triangulate the arms but I went straight. I haven't encountered any probblems with this set up yet. Oh yeah also made panhard bar. Sorry don't have any pics.

 

[tator]

Ratcrazy-
Look at #5 picture in Bob W's on the 31 chev post...There is 1/4"x2" wide pieces of steel straping that is welded to top and rolls around the end back to the bottom, welded back to the botom and both ends of the round tubing. In the way you have shown, the round tubing is not strong enough. If you would have drilled the hole strait thru and welded it all the way around the tubing on both sides the tubing would be holding just the bushing and the arm would be making the strength. So you need to wrap the 1/4" x 2" around the end and weld the exhaust tubing all the way around on both sides and the 2 in strap to your square tubing Tator

 

[Ratcrazy]

Ratcrazy-
Look at #5 picture in Bob W's on the 31 chev post...There is 1/4"x2" wide pieces of steel straping that is welded to top and rolls around the end back to the bottom, welded back to the botom and both ends of the round tubing. In the way you have shown, the round tubing is not strong enough. If you would have drilled the hole strait thru and welded it all the way around the tubing on both sides the tubing would be holding just the bushing and the arm would be making the strength. So you need to wrap the 1/4" x 2" around the end and weld the exhaust tubing all the way around on both sides and the 2 in strap to your square tubing Tator

I had already cut the 2' straps to wrap the sleeves but decided not to use them being I have no way to heat and bend it around the sleeves.

I took another piece of 2x3x3/16 and drilled a two inch hole and then split it down the middle to make two caps. Guess I should have thought of this first but we learn as we go. Will know better next time. Not a nice looking as I would have liked but it will work and be strong doing this way also.

Larry

 

[Ratcrazy]

Up date on two link.

Haven't welded anything in place as of yet. Just have it clamped to the frame for the time being to see how things are lining up.

Seems that I might have to do a little more adjusting to the saddles before welding them solid to the axle.

Shock plates kinda at an angle at the moment.

Larry

 

[Ratcrazy]

Here it is all but the panhard bar in which I plan on finishing this coming weekend:

Thanks for all the comments and suggestion from everyone.

Larry

ps: forgive the blueness of the pictures, new camera and havent figured out all the settings on the lighting