I got my '55 Special yesterday and I've been under it tonight trying to plan the rear suspension for the driveline swap. At first, I thought my only options were: Universal triangulated 4-link Universal parallel 4-link w/ universal panhard rod. What about using the universal parallel 4-link, but reusing the OE panhard rod? What about trying to use the factory lower control arms from the swapped rear along with the OE '55 panhard rod? The last one seems like the cheapest. The only downside I see is not having any adjustments for pinion angle. The other problem is it seems like any of the above lower arms would need to go to the X part of the frame as the X connects to the frame closer than the 20" or so for the lower arm. Thoughts? Thanks, Eric
I used ladder bars & the factory panhard bar on mine. Would get under it and take pics but tha car is currently mothballed in my seperate garage and their isn't any room to jack it up. In the long run it wasn't a super difficult transformation. Was going to do a 4 link on mine, but my friend gave me the ladder bars.
How about trailing arms off a mid '60's Chevy truck? Very cheap and from what i've been told right here, very easy to instal and easy to use with air bags. I was convinced enough to go buy a set for my '51 Chevy someday project. I think I payed just over $20 for both arms and the panhard bar. I could have chiseled the crossmember rivits and taken it too but it looked like it would be easier to just fab my own. Oh and, before you get jumped on with both feet you better do an intro.
Thanks. (I just posted my intro) I guess if the ladder bars work well with the factory panhard rod, the stock lowers should as well. I'm a little concerned about the front mounting though. Where it looks like it would hit the X, would be right where the exhaust hole is. Eric
I went a different route on my (for now anyway) 54 buick. I will prolly in five or ten years put bags and a 4link and slam in down low, but parallel leafs where ok for the hotroddy stance.
I grafted in a mid 80;s Caprice rear. Cut the trailing arms off the original tork tube at the tranny, grafted them to the ones on the Caprice, moved the arms out fastening them to the frame. Used the original panhard bar. Seems to work fine
Zman is correct. The Chev truck style (Nascar arms) are, first of all, much stronger than the original Buick diagonal braces. The Buick torque tube did the "heavy lifting" in the stock setup. The diagonal bars were just to keep the housing square with the torque tube and did not control axle 'wrap' on acceleration or decel. I am currently doing a similar swap on my '40 Super and am using the truck style arms and stock Buick panhard bar. Am using the coil mounts adapted from the original axle. Ray
Ray... thanks. I didn't mean the original 55 arms... yeah...they look way too weak. I was talking about the lower control arms from a later '78-'87 G-body like below... This way I would only have to fab the front mounts for the arm and move the panhard bracket from the old rear to the new rear.
Maybe I am missing something here, but you will have to have at least one upper link to use in conjunction with the lower control arms in the photo. I had been considering a similar setup before I opted for the truck style arms, which do not pivot at the axle, and therefore do not need any upper control link. I was looking at using Jeep Liberty lower arms, and maybe the triangulated upper control link, since the triangle arm eliminates the need for a seperate panhard bar. The reason I considered the jeep arms is that they have nice cushy rubber bushings on both ends and and are upside down "C" shaped and can absorb the twist induced in the axle housing when the car leans in a turn. Ladder bars, 4 link bars or 3 link bars, if mounted parallel, will bind and bend and try to twist the axle housing when the body leans. However, if the ladder bars, or the 'truck arms', are mounted where the front of the bars is very close to the center of the chassis it minimizes the twisting force. A single center pivot, like a Ford wishbone, would be ideal for eliminating the twist, as does the Buick and early ford torque tube drivelines. There is more going on there than meets the eye and all the geometry and physics ought to be taken into consideration to get the best results. It's not all that complicated, really, but awareness helps. Best wishes, Ray
I'm doing this same transition with my '55. I've picked up a '65 Wildcat rearend.. will pickup the stock arms for that rear (I've located a few people who will sell them)... and I'll just fab any hookups that are necessary. This rear has a triangulated setup so I won't have to use the panhard bar. I'll also put some air shocks in the back to use when I've got something heavy in the back... However this is all on hold until I get my flippin' '49 Chevy done. Long ways to go.
I removed the torque tube on my '55 Special and used the stock rear end. I tried ladder bars to locate the axle, but stress cracked the axle housing where the ladder mount brackets were placed. I welded up the cracks and then obtained a pair of compliant rod ends from Speedway that had polyurethane bushings and installed them in the bottom bars of the ladder bars. That seemed to solve the problem and I haven't had any further cracking. Unfortunately, Speedway discontinued carrying those rod ends and I haven't been able to find them elsewhere.
And easy. I set it up in a few hours and you can use whatever rear you want Sent from my iPhone using Tapatalk
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