Rear leaf spring fanned

[mcditalia]

I noticed that the new Eaton spring I installed a couple years ago "fanned" and made the end link bolts crooked. When they shipped the spring to me it came with clip bands that were taken off during the installation. Should these have remained on? What else can be done to prevent this from happening again?

 

[Midnight 99]

The bands around the spring pack are there to prevent each leaf from walking away. The best solution now would be to have someone with a portable banding tool band them back together after to tap them all back into place. You should be able to do that with a block of wood and a hammer so you aren't marring the edges of the springs.

 

[Vettehead Mikey]

The bands are for shipping purposes only. The most common cause for the 'fanning' is having an incorrect replacement differential rear housing. There two different widths for C2/C3 rear springs, with two different housing widths as measured by the distance between the centre spring retaining bolts.

Your car would have originally had a 'narrow' spring and narrow cover. At some time someone inadvertently installed a replacement 'wide' rear cover. The resultant gap allows the leaves to splay outwards. A pair of shims can be installed to fill the gap and keep things aligned.

I think the 'wide' rear covers were introduced with the later C3 cars. Most heavy duty replacement rear covers are the wide type.

 

[mcditalia]

I was unaware of that. My cover casting number is 3871375 if I'm reading the 3's as 3's and not 8's. The measurements by the ears are 3" by 5 1/2" at the 4 bolts. Spring appears to be 2 1/4 to 2 1/2" by the leaves, same diameter as the old spring I took out that never fanned.

One thing I cant be sure of is if the cover was changed when the spring was swapped. The guy doing the work had a problem sealing it right and had to take it apart a second time after he did the work. Not sure if he swapped the diff cover then.

 

[JohnZ]

I was unaware of that. My cover casting number is 3871375 if I'm reading the 3's as 3's and not 8's. The measurements by the ears are 3" by 5 1/2" at the 4 bolts. Spring appears to be 2 1/4 to 2 1/2" by the leaves, same diameter as the old spring I took out that never fanned.

One thing I cant be sure of is if the cover was changed when the spring was swapped. The guy doing the work had a problem sealing it right and had to take it apart a second time after he did the work. Not sure if he swapped the diff cover then.

The leaf spring was 2-1/4" wide from '63-'77, and changed to 2-1/2" for '78-'79. The rear cover casting number didn't change - what DID change was the diameter of the four bolts retaining the spring to the cover. To accommodate the wider spring, the 9/16" bolts were changed to 7/16" and the hole pattern was widened fore-aft (machining changes); that's why the retainer plate is also different (7/16" bolt holes instead of 9/16", different pattern).

If a 2-1/4"-wide ('63-'77) spring is used with a '78-79 rear cover with 7/16" bolts, it will "fan" unless the correct pair of fore and aft steel shims are used to fill the empty space between the edges of the narrower 2-1/4" spring and the O.D. of the smaller-diameter 7/16" bolts.

 

[mcditalia]

Thanks to everyone. I didn't have much time lately to look into the spring, she sits in the garage on 4 jack stands. Unfortunately when i start a job, like i originally did by changing the gas tank, it always progresses to something else...brake calipers, leaf spring...etc. and then no more time to finish:eyerole. I will check out the bolt sizes and spring more closely, at least i know what to look for now.. Thanks.