Technical 34 ford pu twisted rear shackles

Need some advice of what to check on why my rear shackles became twisted. This is a ground up build with original frame and rear x member, newly rebuild 34 banjo rear end, a used Posies 32-34 compound curve rear spring, and Speedway shackles with the black nylon bushings. I installed the drive shaft and torque tube on the rear, bolted on the main leaf and proceeded to build the spring pack using a threaded rod and clamps so I could install spring center bolt. All went well until I slide the entire assembly into place under the chassis. I don’t have a motor/trans installed yet so just made sure front end of torque tube was on top of the frame “u” where it will bolt to trans. As I began to jack the rear end up to seat the spring into the rear crossmember, making sure to align the spring pack bolt head into center hole of the crossmember I noticed that it wasn’t lined up right. It seemed to be leaning back so I used some ratchet straps around the spring and axle tube, one on each side, to pull the spring top forward. Installed the spring ubolts snug for mock-up and put jack stands under the axle tubes. At this point I noticed the spring shackles are twisted and the spring eyelet and axle tube spring eyelets aren’t parallel to one another. See picture. What did I do wrong? Or what is wrong? Can I drive it like this? Are the main spring eyelets bent?

 

Have the mounts on the axle housings been modified to match a straight spring? The shackle bolts in the axel housing do not appear to be parallel to the eye of the spring.

 

I don’t know since I am using a different 34 axle housings and center section than my original. I do still have the original housing as well as a third set. I will compare the axle housing mounts on all of them.

 

The axle mounts look like they have been modified.... Looks like they have been welded.... Hard to tell from the picture.....

 

That spring doesn't look right.
I'd like to see it along side an original 1932 / 34 spring.

 

A 33-34 with a four cylinder had a different length torquetube. I think it was longer, but I may be backwards. If you mistakenly used a 4 cylinder rearend and then forced the axle/spring into the crossmember, it might be jammed in their crooked. Compare the length of your torquetubes.

 

Is that a crack on the top of the axle side of the shackle mount?

 

I have had to heat and bend the arms to be parallel on a couple rear ends. The spring is curved, but the arms, or shackle mount point is still supposed to be square with the world, or parallel to each other

 

The 32-34 spring should curve into mounts. Your mounts are curved, but the spring looks straight.

 

As Hemihotrod66 said: It looks like the mount was welded and the weld ground almost smooth, it doesn't mean it's not in the correct location if it was welded. Especialy if you don't have the curved rear spring but we can't see because the pictures are too taken close.

 

Using a four foot long straight edge I checked the spring eyes on a Posie’s ‘32 rear spring I have, they are 5* off perpendicular using a machinist’s protractor.

 

Draw a line through the dots:


Unless this is camera distortion, your spring mount is bent.

Based on the position of the side plates on this shackle, I would say that it is.

The bore of this mount absolutely must be parallel with the flange on the axle for the brakes.

It appears that it is perpendicular to the axle tube, which is tapered, not straight.

 

Better to view the whole scene

What he says.

 

Nope. 32-34 has a curved spring, so that’s not the case.

 

I still have the original spring that I can compare to the Posies spring. Both springs are compound curved the same. I only have one torque tube, the original one, that is being used. I will post pictures too.

by the way, I failed to mention in first post that both left and right shackles are twisted not just the one side shown in the picture.

All these questions have now made me realize that when I was playing around with the mock up of the pu for ride height using the original rear, torque tube and the original spring pack, sans about half of the original springs, I had the exact same problem…I just thought because the shackle bushings were completely gone it was giving me trouble going back in the crossmember.

 

so that would mean spring mounts on both pairs of axle housing are bent out of shape..!!
I just compared my OG axle housings spring mounts to one’s I have installed and they appear to be the same angle in regards to center line of the axle housing.

Next will compare spring packs.

 

Putting the curved spring in the wrong way around could explain this?

Chris

 

best answer so far

 

I suppose but it will not fit another way. The crossmember and spring are curved the same.

 

My 32 sedan with an original rear and spring has a little bit of misalignment on the shackles too. I don't think I have anything bent, it's just the nature of that curved spring.

The OPs hangars have had the small knobs removed from the top that the shock links attached to. That is the smoothed ground spot that was questioned above.

 

yes, the shock knobs have been removed from the tops of the mounts by me. I am going to use aftermarket shocks.

so I guess the definitive answer is I need to heat and bend the axle spring mounts to match the spring eyelets? If so, That really sucks because everything is powder coated..!

I assume if I just run it as is I am risking damage or breakage of those shackles and maybe more.

 

OK. What if the main leaf was the wrong way around?

It would be useful to see the angles of the spring ends with the spring disassembled. There's always the possibility that the orientation of the eyes has been formed incorrectly relative to the curve of the spring (or vice versa), in which case it becomes Posies problem , I guess.

Chris ​

 

With all due respect, I don’t see how the main leaf could be put in the wrong way. All leafs are curved the same. No way it could be put back together backwards.

it is possible that the main leaf eyes are out of whack since this is a second hand unit. I didn’t buy it new from Posies. I’ll post pictures of old and new spring side by side sometime today.

 

So wrong! 1932 / 1934 spring hangers are set at an angle (about 6 degrees) to accommodate the
curved spring.

 

nope! not on 1932 / 34

 

Have to Tried to Load it with weight to get your shackles at the correct degree? It might work it self out to be acceptable when it's under load. Those '32-'34 curved rear springs can be a little goofy. I'm working on one now also.

 

that’s the best idea yet but I am a ways off from placing the bed, fenders, fuel tank, etc on there to see how it settles. Guess I will wait and see.

 

or stack blocks or bags for weight

 

I truly have no idea of how the rear suspension is laid out in one of these cars. But is there any possibility that the rear crossmember could have been installed in the wrong orientation for the spring curvature?