Can anyone tell me how to safely replace the rear shackles on a 39 Ford Coupe? I know messing around with the transverse spring can be dangerous and I don't want to unbolt something that I shouldn't while the spring is right in front of my face.
Is the purpose of the spring spreader to essentially keep the spring in the same position, and to take the pressure off of the shackles so that the shackle bolts can be easily removed? I don't have a lift. Where is the best place on the car to palce the jackstands while doing this -- the rear axle?
you need to support the frame with jackstands , putting them under the rear will do no good once you remove the shackles.
Good point. Obviously this is the first time I've done this, and it is tough to tell just by looking at everything how it all works together. Should I try and find someone that knows what they are doing to replace the shackles for me, and watch them so I can learn. Or is this the type of job that a first-timer should try? I've only worked on cars '65 and newer prior to this '39.
i think you can do it yourself if you are careful and have access to the proper tools. you will need a floor jack , some heavy duty jackstands and hopefully a spring spreader. you will also need to chock the front wheels so the car doesn't move on you. if you don't have a spring spreader you will need to dis-assemble the rear spring pack so you can work with it. i have a spring spreader , but it's a little far away for me to just stop over are these stock type ford shackles/bushings...or replacement hot rod type?
I think it's something that you are capable of doing. I have only pulled a few rear and I'm actually going to do one this weekend and I feel capable of doing it. My neighbor used to put a 2x4 cut to length between the spring so that it does not pop...or at least thats the gist I got from it. When I pulled 39 front a few weeks ago it let me back the nuts off fine then when I yanked on the front end it finally popped.
A fairly easy way without a real spreader, the way I used to do this. NOTE THE SAFETY CHAIN PART...this is effectively a medieval artillery piece once cocked! You can easily fire your spreader through yourself and the next 3 buildings in range! Crawl under the bumper with car still on ground...you need its weight. Cut the ends off of a 2X4 at 45 degree angles \ / or a bit sharper so that it is about 3/4--1 inch too ong to go between shacles with the points in where the spring eye rolls away from spring. Crawl out; add a couple of hardware eyes with some chain at each end to wrap and bolt around spring for safety under compression. 2x4 should obviously be a good one without cracks or knots. Put a fat friend or two or tool boxes in trunk until spring spreads enough for your board to go into place. Now jack up frame, block it up ahead of wheels, and hold up axle with a scissors jack under the banjo. Spring is held by the 2x4 and you can disassemble shackles. Be very careful with the safety stuff...this is a seriously overpowered crossbow if it launches an unsecured 2x4!
Well now you have talked me out of it Bruce. Hahaha, man I had no idea they were under such a load??? Is a '36 the same way? My front came out with no pop at all.
I'm not 100% sure that the shackles are the stock ford type, but I think they are. I am going to replace them with lowering shackles that I bought from Vern Tardel. Lowering the car is the reason I am doing this.
Might not be safe but when I was young we just supported the frame with stands and put a big bottle jack under the spring eye one side at a time took the nuts off knocked the shakles off , let the jack down until the longer shackels would go on. That's how we all did it in the 50's. Do block the wheels.
That seems fairly simple. Can anyone think if why this way isn't a good idea --especially if you could brace the bottle jack in suck a way that it can't be forced out of the way of the spring.
For me getting the spring out of the car is the easy part. Getting the metal sleeved shackle pins out out of the spring eyes and shackle mounts can be a PITA especially while still on the car. The real tough part is pressing the new steel sleeved rubber lined shackle pins back in place. They tend to be a little over sized and want to seize up half way in. If you are using original style replacements, chuck them up in a drill press and sand them a little to reduce the diameter a bit. Lots of grease to ease them back in. The 2 piece plastic hot rod bushings are much much easier.
Bottle jack way should work...you may still need to add weight to lengthen spring a tad. Lowering shacles will require anti-sway in back...look at a '46-8 Ford for one way. Longer shackles will allow car to swing back and forth sideways on the shackles like it's drunk...with no bar, shackles on a Ford need to be 45 degrees or less to avoid sway, and long shackles (or a sagging spring) will mess this up.
Like Tommy said, the hard part is digging out the pieces of old shackle in the radius rod. I usually use an air hammer/chisel and some heat if they're real bad. Take the whole rearend out will make this alot easier. It's kind of a hassle to undo the torktube ball/ujoints and all, but the job will be alot easier. If you know how to use a sawzall or torch, just cut one spring perch off, (front first) there will be a spring pop but it won't jump out since its connected to the other perch. This is a good excuse to take all the leaves apart, smooth out the leaves and grease em up. Its alot easier to put back in just the main leaf. Then just use a really long guide bolt and put each leaf back on, using 2 clamps on either side of the hole as you swap out the bolts, cause they will bust out if your not careful. (and 1 or 2 clamps perpendicular to the springs to keep them all lined up) I have a stack of spacer nuts/bushings and usually only use one long bolt, but make sure you have the threaded part on the top, so when you replace it with the real spring bolt, you can just tap the guide bolt out without removing it. TP
i believe he is just replacing the bars , not the bushings and pins http://www.verntardel.com/collections/suspension/products/lowering-shackles
Exactly -- I'm just replacing the bars. I thought the bolts would come right out once the spring wasn't holding them tight. Bruce -- thanks for the advice on the sway bar. I hadn't thought of that.
I see that the pins are not getting changed this time around, but I remember well trying to get those pins out of my 39 when I was a kid. I finally got the old ones out by heating the eyes on the rear. Lika a dumb ass kid, I decided to "dry run" the new one just to check the fit. Well it was still hot as shit, almost instantly I thought "bad idea" and tried to reverse direction, too late, stuck the new pin halfway in.... bought a new one.....
Just swapping the bars is easier than replacing the full shackle set. Work on only one side at a time. After the bars on the first side are installed, the second will be even easier.
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