Technical 49 Buick Rear Suspension Questions

The 49 Buick I bought has a shortened, cobbled up triangulated 4 link rear suspension. It's ugly and doesn't work very well. It uses a GM 10 bolt rear with factory 4 link setup.

I have been researching and trying to figure out what I can do to straighten out this mess. It seems that the late 60's-72 Chevy truck suspension might be a good direction. It doesn't look like a 4 link parallel setup will fit vey well.

I have not been able to find any good pictures of the Chevy truck setup. I know that the bars are sort of triangulated inward and that it uses a pan hard bar to locate the rear laterally. How does the rear axle "pivot? I.e. How does one side go high while the other goes low without binding?

Is it easy to custom fab one of these setups using tubing? Are there any pre- engineered kits available?

Please post some pics showing me the business ends of these setups so that I can understand them better and/ or point me to some links. Any precautionary advice is appreciated, too.

Thanks!

 

Any experience with adding a 4 link parallel?

 

I used a rear frame section from a 1978 El Camino, Chevelle etc. its all in one unit and you wont need a pan hard bar as it is also tri-angulated. They are easily available cheap. If you're lucky your rear end might just bolt right up to it.

 

PM telekenfun (KB) here on the HAMB. He updated the rear suspension on his wife's 49 Super. Can give you the low down on what he did to it.

 

I don't think there is room for it. That's why the original 4 link arms have been shortened. It's also not aligned very well, so it binds up on droop.

Thanks

 

After some research, I found out that Hot Rods To Hell makes a kit designed after the Chevy truck suspension but made for the Buick. This is an option but I'm not sure I'm ready to bite it off at this time.
http://hotrodstohell.net/truckarm/truckarm_index.htm

 

The Chev pickup bars are made in an I beam shape, of 2 stamped mild steel C channels rivetted together. They did this so they could twist.

If I was making them I would use square tubing but at the front, use a donut shaped rubber bushing the same as Ford used on their twin I beam front axle. This would allow twisting, forward and rearward compliance, while being silent and shock absorbing.

A lot depends on how bad the car is hacked up. With the original rear axle springs etc gone, it might be easier to do the 4 link. Or even a full IRS.

 

Thanks for that explanation. It makes perfect sense. I've got some other fish to fry before I tackle this but I appreciate the inputs.

 

We had a '54 Special that someone had grafted in a frame section from like a '69 Riviera (which then rotted out at the forward kick up) to convert it to open drive. I can't imagine there not being room under one of these for something like that. But I would look at keeping the Buick side rails and transferring over the frame crossmembers and mounts only.

 

How about building the arms out of square tubing and using jonny joints?

 

Square tubing, or round tubing for that matter, totally defeats the engineering that GM
put into the 'truck arm' suspension design. Even with compliant/flexible front bushings, which GM had in their design by the way, the control arm being able to twist along it's length allows the suspension to function without undue stress in any of the components. The GM design "I" beam arm is the design to copy. Other kits and homemade square/round tubing designs either misunderstand, or ignore, the forces at work. Also, it is important that the front of the arms be located as close to the center as practical, i.e. immediately either side of the driveshaft. That triangulation also greatly reduces the twisting forces.

Besides, the Buick 'X' member may as well have been custom made for the truck arm suspension. it is so much easier, and probably more effective, than any of the other alternatives commonly tried.

 

I had a friend that does fab work bend up a set of truck arms. I made a bracket that mounted them to the x member. He made up a new pan hard bar. I put in a rear end from a 78 Malibu and the set up works great. Didn't break the bank either. I can e mail pics if you want.

 

Art Morrison triangulated 4 bar works great

This is one we put on the 47 Olds



This one went on the 1955 Buick


Russ used metal plate to make sure the frame was strong enough at the mount points

 

That AM set up looks pretty simple and slick. Is that a standard kit?

 

there is a thread on here that I just read a week or so ago about installing a Chev truck system on a Buick.. Done in a rod shop with a 348 up against the Buick drive train that did not work long, then back to the shop for the conversion. I can't seem to locate the thread if anyone can help find it.

 

Found it! Scroll down thru the posts and you will see how he did it. Nice install.

http://www.jalopyjournal.com/forum/threads/buick-torque-tube-to-open-driveline.578566/#post-7794950

 

I used an 81 Caprice rear end and joined the original trailing arms to the Caprices and mounted the front of the arms to the X frame. Used the original pan hard bar. It sounds like you don't have any of the original rear suspension left so this may not be possible.

 

As Fat 47 said, I was about to suggest the same, use OEM Buick arms and brackets, coils if you still have them and adapt coilovers or conventional shocks to your open drive train. I adapted a 1947 Olds '66' trailing arm suspension with centre X-member to a friends 42 Chevy PU and used coilovers in lieu of OEM coil springs and lever actions. Olds trailing arms are top hat design like Chevy truck and should work a treat with OEM sway bar. OEM rubbers and bushes are still available as well.

 

OEM Olds arms and OEM Buick arms are apples to oranges. The Olds arms are much stronger as they are comparable to the Chevy truck arms in that they are the sole control of axle torque. The Buick diagonal "arms" did not control ANY torque forces, the torque tube did that. The Buick pieces only served to keep the axle housing 'square' with the torque tube in exactly the same manner as Ford torque tube so-called radius rods. It has been proven several times that neither the Ford or Buick radius rods are strong enough to control a rear axle torque. They fail in one manner or another.

 

After seeing that Art Morrison Tri 4 Link, that may be the way to go for me, given what I have to work with. I have none of the OOE pieces. All I have is a cobbled up GM 4 link that binds and the driveshaft hits the crossmember. I'm going to cut all that shit out and redo everything to work with my my 10 bolt rear.

 

Ok. I have talked to the guys at Art Morrison and Hot Rods to Hell. I thin the easiest to install (none of them are straightforward easy) will be a parallel 4 link and pan hard bar.

The only problem is, I am going to have to cut my X member to install towers to mount the forward mounts on. It looks to me that the best way to do this, with the body on the frame, is to box the rear portion forward to the towers, tie the X member into the towers and gusset the corners forward of the towers.

The other possible option is to build a crossmember with a hoop for the driveshaft and holes for the exhaust pipes. Mount it across the frame and cut the X rails to tie into the cross member. Probably 2 X 4 tubing. This is probably the best. Also, I would need to box the rearward portion to the cross member.

Will that work? Is there a better way?

 

"Is there a better way" yes.......I think so

I don't know if "Webrodder" website is still on the net, but there is/was a great tutorial on installing 4 bar with panhard bar on '51 Buick and would be an excellent series of photos to view before tackling this install. I'll see if I can find it and post a web address if I do.

EDIT: Found it! go here... www.webrodder.com/articles?page=3&category=5
go about hallway down the page on the left side article titles to "Buick 8 Fireball" Part 1 and Part 2.
Several more articles for mods to this Buick that offer some good insight.

 

I will spend a few dollars to see what is in these articles. Thanks for the lead.

 

Crap. Webrodder doesn't work with ipad. I'll have to look at it at work.

 

I am on my iPad now.....saw your post and tried it...opened for me.

 

Mine wouldn't load it because it used Flash....which Apple doesn't support. What kind of app do you have for that?

 

I have no idea. It just 'works'.........

 

My 48 Olds convert has the chevy truck type suspension from the factory. The car rides great. I thought Byuck also had this type of suspension. I know Cad ran it, and i thought all big cars in 48 and 49 used it. If you could find a frame with this tyoe of suspension it would be an easy install

 

Here are some pics of a parallel 4 bar installation on (I think) a Buick chassis.

 

That's nice but they did it with the body off. They shortened the rear X frame members and moved them back into the side rails forward of the original attachment points, then they boxed everything back to the original boxing. I'm not sure I will be able to do that without taking the body off.