I'll post part II once I get the car on jackstands and get the old one out. I had other projects for this weekend already lined up. New brake pads on the wife's car, build a kitchen hutch for my sister, clean the house etc. I ordered from Corvette Central, and I'll get a pic of new spring and old spring side by side when I get it in about a week. I just hope to get it all back and driving by the weekend after Easter for the Mid Mo Corvette Cup - short of anything "popping" up I think it's very doable. Look for Part II coming in a couple days. I think the toughest part will be either cutting the exhaust out (hopefully won't have to) and/or getting the broken bolt out with my EZ out.

 

While dropping my spring several weeks ago (rear end restoration underway), I noticed that oil started dripping from somewhere almost as soon as the bolts came out of the differential. Nothing major, but odd. I should mention that the previous owner had replaced the original spring with an aftermarket 7 leaf spring several years before I bought the car.

Anyway, we removed the differential and poured the old gear oil out. While prepping it for the sandblaster, we finger tightened two bolts back into the rear cover to provide some support on the back side while it was in the blasting cabinet.

Once the blasting was done, we pulled the dif back out and pulled the rear cover to have a look inside. It turns out that one of the bolts had been overtightened and had cracked the boss on the inside of the cover! After cleaning the cover thoroughly, we found that the crack could be moved up and down with a finger. This sucker could have popped off at any time and would have destroyed the rear end.

I decided to check and see how long the bolt should be for a 7-leaf spring. According to Zip, the bolt should be 3 1/4" in length. The ones we removed were 3 3/4" and there were no washers in place.

Not wanting to risk the obvious, I ordered a new heavy duty rear cover from VBP. When speaking to tech support, I was told that this can also be caused by using an impact wrench with a correct length bolt.
I was advised to use a torque wrench when putting the new bolts in. Since I didn't own one, I had an excuse to go to Sears and pick one up.

For anyone who is planning to do any work under the car, all I can say is be prepared for ANYTHING. The things we are finding under my car are scary! Six of 8 nuts attached to the driveshaft u-bolts were finger tight. The rear e-break cable was attached to the trailing arm with plastic ties. My rear cross over break line (from left to right side) had been broken, removed from the proper clips, and spliced back together, the differential oil fill bolt was finger tight, the battery cable was laying on the drive shaft. It does pay to get to know your car from the bottom up!

Mark

 

.... what's wrong with the plastic ties ??

 

A friend told me right after I got my Vette to replace the old spring. He said he had a couple C3's and the rear spring broke and took out his entire rear quarter. Looking at those pics and Lakostarose's I can't see how that could happen??

 

I got the old spring out last night. Here is what I thinkg happened.

2 things:
1) The anchor plate was warped, or twisted becuase of only having three bolts in it.
2) The little bolt in the middle of the spring that holds it all as one piece was rusted in half.

My wife and I heard two noises when it happend, so I suspect, noise 1 was the spring twisting and breaking the rusty bolt, and the second noise was when the second leaf (from the bottom) started dragging on the ground!

I got the 3 bolts out and wham, all the little leaves fell to the ground. There was no other damage, and I did have to cut out the exhaust since it is welded in 1 single piece from exhaust manifolds to exhaust tips.

I don't see how it could mess with rear quarters unless he had extra wide tires or something. I've got stock trailing arms and 255 60 15s and their was about a pinkie finger width between tire and the inner fender when it was on the bump stops. The tire was up inside the inner fender by about 1 or 1 1/2". Now I just have to wait for the spring to arrive.