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Since you changed the spring and liners (rear spring assembly) the four spring attaching bolts to the rear axle cover may not be the correct length. The most critical of these are the two bolts that thread into blind holes. Too short of bolt and you do not have sufficient threads engaged for final torqueing. Too long of a bolt in these blind holes and you will crack the rear cover plate. For now, keep these bolts only finger tight and without the lock washers installed. When the spring is correctly installed, it will flatten the center of the spring firmly against the rear cover plate. At this time, check to be sure the bolts going into the thru holes have enough thread to have 1-2 threads protruding above the cover. Make this check by tightening these bolts only finger tight. Do the same check for the two bolts going into the blind holes. You should be able to finger tighten them firmly against the spring retaining plate. If you cannot, they are too long. If you can finger tighten them, then remove one at a time and measure the total depth of the hole and spring and retaining plate, and the length of each bolt, to see if they are too short. If so, buy new bolts and cut to fit.
Finally, install all the lock washers (4) one at a time. These will give you about 3/32 to 1/8 inch additional clearance in the blind holes to allow for bolt stretch etc. when tightening without causing any metal to metal interference. For the thru-hole bolts, the lock washers will lower the protruding end of the bolt about 1-2 threads.......making it about even with the top of the cover plate
Only tighten these four bolts with a wrench after you have the car back on the ground on all four wheels. Failure to do this can be a painful learning experience, as it can cause the rear axle cover plate "ears" and/or casing to crack. Too many have learned this the hard way........don't be one of them.
Since you changed the spring and liners (rear spring assembly) the four spring attaching bolts to the rear axle cover may not be the correct length. The most critical of these are the two bolts that thread into blind holes. Too short of bolt and you do not have sufficient threads engaged for final torqueing. Too long of a bolt in these blind holes and you will crack the rear cover plate. For now, keep these bolts only finger tight and without the lock washers installed. When the spring is correctly installed, it will flatten the center of the spring firmly against the rear cover plate. At this time, check to be sure the bolts going into the thru holes have enough thread to have 1-2 threads protruding above the cover. Make this check by tightening these bolts only finger tight. Do the same check for the two bolts going into the blind holes. You should be able to finger tighten them firmly against the spring retaining plate. If you cannot, they are too long. If you can finger tighten them, then remove one at a time and measure the total depth of the hole and spring and retaining plate, and the length of each bolt, to see if they are too short. If so, buy new bolts and cut to fit.
Finally, install all the lock washers (4) one at a time. These will give you about 3/32 to 1/8 inch additional clearance in the blind holes to allow for bolt stretch etc. when tightening without causing any metal to metal interference. For the thru-hole bolts, the lock washers will lower the protruding end of the bolt about 1-2 threads.......making it about even with the top of the cover plate
Only tighten these four bolts with a wrench after you have the car back on the ground on all four wheels. Failure to do this can be a painful learning experience, as it can cause the rear axle cover plate "ears" and/or casing to crack. Too many have learned this the hard way........don't be one of them.
Larry
Larry this is a new untouched spring from either Ecklers or Corvette Central. Don't remember which. It's been too long. It still has the two bands wrapped around it. Bolts have been a problem. I tried putting 4"in and they bottomed
out. I put 3 1/2"in and they were fine. I do have the original bolts and they are 3 1/2". 4" bolts are an option. I don't know which spring would take 4". Unless my original spring was a 7 leaf and it used the 3 1/2"bolts that I have.
I don't have the original spring. I tossed it years ago. But I do have to sets of different size bolts. I don't remember the torque specs but I felt like something wanted to strip or break when I was tightening down the spring. I'm not going
to tighten it to specs but will use some 243 blue thread lock.
Thanks Larry
I always cut my rear spring bolts to exact fit for the car and the spring installed. ALWAYS..............
That way I know all is well.
Springs and liner thickness vary from one to the other, none are the same anymore. Don't assume that they are.
FWIW.
Larry
EDIT: As a point of reference, Paragon sells these bolts: for 7 leaf spring they are 3-5/16 inch long. The ones for the 9-leaf are 3-9/16 inch. I have had to cut the Paragon bolts at times to get the correct fit for the blind holes. Again, this was necessary due to spring and liner thickness variations.
Last edited by Powershift; 10-30-2018 at 11:52 AM.
If the head of the center bolt holding the leaves together is too high, it will not allow the spring to lay flat against the differential mount boss. If that bolt head is too high it could tilt the spring assembly in one direction, as well as cause it to punch through the differential when it's torqued.
You may want to remove the spring and verify that's not the problem.
Last edited by rich5962; 10-30-2018 at 12:42 PM.
Reason: pics
If the head of the center bolt holding the leaves together is too high, it will not allow the spring to lay flat against the differential mount boss. If that bolt head is too high it could tilt the spring assembly in one direction, as well as cause it to punch through the differential when it's torqued.
You may want to remove the spring and verify that's not the problem.
I'll do that Rich. Thanks. I'll also attach the metal cups to the spring. Plus I have new bushings coming. I ruined 2 of them trying to install them.
Still no luck getting the spring attached to the other trailing arm. It lacks at least 2 inches from lining up with the hole in the spring. I ruined 3 of the rubber
bushings so I bought new poly ones from Energy. I still got one side on but the other was a bear. I tried it with the 2 back spring plate mounting screws
removed. The spring came flying out. I'll tell ya, messing with these springs are dangerous. I'm going to buy a ratcheting strap and wrap it around the spring
and 1/2 drive to see if I can pull them together.
Still no luck getting the spring attached to the other trailing arm. It lacks at least 2 inches from lining up with the hole in the spring. I ruined 3 of the rubber
bushings so I bought new poly ones from Energy. I still got one side on but the other was a bear. I tried it with the 2 back spring plate mounting screws
removed. The spring came flying out. I'll tell ya, messing with these springs are dangerous. I'm going to buy a ratcheting strap and wrap it around the spring
and 1/2 drive to see if I can pull them together.
Butch
S. Jersey
Something is not lining up (frustrating).
Be safe. Never load the spring unless all four bolts at the pumpkin cover are installed. They only need to be in the holes about three thread engagement turns, or about two turns out from finger tight, to allow the spring to flatten while holding the spring location correct. The spring pack center bolt head will keep the spring from moving out of place.
Is the same side the one that is not lining up?
The upper bushing and long spring end bolt should be in the trailing arm and loose before loading the spring end, and the bolt should remain loose as you load the spring into position (even if the spring end pushes the long bolt up and partially out of the trailing arm). With the spring end loaded and stable, you should be able to raise or lower the trailing arm to drop and wiggle the long bolt through the spring eye (like the photo in post #3), before installing the lower bushing, washer, and nut under the spring eye hole.
Can you post a photo when you get close to the loaded and secure position shown in the photo of post #3?
You can see how far off the bolt is off. If you raise the trailing arm the bolt gets closer but it then won't reach the spring. I have spent days on this. Was thinking of using a com along between the
frame and the spring. There have been no signs that the frame is bent. This is driving me nuts.
It's been a while since I put my seven leaf spring in.... But, I think you need to go back to Post #18 where 63 340HP tells you to put the strut rods on and do the spring last.
You appear to have the trailing arm supported on a jack stand which is holding it out of reach. Or, I could be totally wrong.
It's been a while since I put my seven leaf spring in.... But, I think you need to go back to Post #18 where 63 340HP tells you to put the strut rods on and do the spring last.
You appear to have the trailing arm supported on a jack stand which is holding it out of reach. Or, I could be totally wrong.
It,s not a 7 leaf!! It's a 9 leaf. I discovered this when I was taking photos. That makes it more disheartening. Here I thought I was working on a
stiff spring and then find out it's the stock spring. I bought the spring new 15 years ago. Don't know why. I had two 66's back then.
You need to quit trying to force that spring on until you find the issue - maybe it is the strut rods...
If you force that spring on with a come-along you're suspension will be in a bind...nothing good will come from that.
I can go back and try to connect the strut rods. I've tried every combination possible, Strut rods on, strut rods off, trailing arms up, trailing arms down, Spring mount tight, spring mount loose, rear two bolts of spring mount removed. That was stupid and almost got killed by the flying spring. I've used one jack and I've used 2 jacks. I've located them everywhere. The only thing left I can think of doing is hooking the edge of the spring with a come along and run it to somewhere on the chassis and start cranking.
You need to quit trying to force that spring on until you find the issue - maybe it is the strut rods...
If you force that spring on with a come-along you're suspension will be in a bind...nothing good will come from that.
Frankie I'm lost trying to find out the issue. There's only a couple parts to deal with. Unless I have a bent chassis but there was never any signs of a frame problem. I'm lost.
They make longer spring bolts, 8", which may give you the added inches you need, if you don't have them already. Not sure you'd want to remove the one you have in already.
10-29-2018, 08:20 PM
