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VBP Spring/Differential Questions

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Old Mar 12, 2018 | 01:46 AM
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Default VBP Spring/Differential Questions

Hi all,

I'm back at it with the car. Finally got some time to start working on replacing my cracked stock spring. While removing it, I came across some questions I figured I'd ask from those with experience.

1. The VBP instruction sheet doesn't mention anything about transferring over any existing shims/brackets, etc. to the new mount. Is that correct? My '82 has two aluminum shims, plus more on top of that, and also a vertical spacer plate that fits between the differential mount. Leave that out too? I don't like the gap between the spring and the two rear bolts.











2. My bottom mounting plate looks to have been over torqued by someone in the past. Does it look acceptable to use, or should I start hunting down a replacement?









3. The entire rear of the car is disgusting, because the diff seals leak so bad. This picture was taken after 4 cans of brake cleaner, so you can only imagine what it looked like beforehand. Between the leaking, and the unbearable howling at 35-55 mph, I really need to take care of this thing. Are there any companies out there who work on the aluminum units, or should I just buy a rebuild kit and do it at home?





I ended up lowering the car down with the plate just snugged up on the spring to hold it in place. The ride height is spot on! Oh, and all that fluid next to the car is not from the car. One of my older floor jacks decided to blow a seal. PSA: ALWAYS use jack stands!




No compressing needed! Yes, I will replace the rubber cushions. The stock bolts are perfect length though.



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Old Mar 12, 2018 | 06:24 PM
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I Have a complete center section for this car that's in nice shape. If need be.
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Old Mar 12, 2018 | 06:25 PM
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FYI- The "rubber" (or whatever they are made of) pads on my 66 VBP spring have lasted forever. That car has side pipes... no exhaust heat under the car. My 1970 VBP pads have turned to mush.... like melted tar. I had to order replacements. That car has OEM under car exhaust pipes that run right next to the VBP pads. I have to either wrap the pipes this time or install side pipes.
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Old Mar 12, 2018 | 06:54 PM
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I think you definitely need to reinstall the vertical spacer plate.
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Old Mar 12, 2018 | 10:19 PM
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You need to do a few measurements first.

1. Width of the original spring Either 2.5" or 2 1/4"(FE7)
2. The diff housing mounting width for the spring. Could be 2.5" or 2 1/4".
3. The width of the lower mounting plate. again 2.5" or 2 1/4"

if your diff is 2.5" mounting then the lower plate needs to be 2.5" and use these to make up the space between the spring and the mounting bolts.

https://www.ecklerscorvette.com/1978...e7-option.html



You need to make sure the diff and lower plate are a match. either 2.5" or 2 1/4" Then measure the spring width. If the spring is 2.5" then no side plates / spacers are required. If the spring is 2 1/4" then you need the spacers.


Upper and lower spacers for a steel spring (OEM) I don't recall seeing one on my 78. When I changed to the VB&P mono spring I used the supplied spacer on the top only.

Also you may need to provide factory heat shield to protect the mono spring or wrap the exhaust.

Last edited by cagotzmann; Mar 12, 2018 at 10:21 PM.
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Old Mar 13, 2018 | 08:50 AM
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If someone purchased & installed the spring kit that includes bolt inserts (helicoils) to reduce the bolt size (for a larger width spring), that may come into play as well. I had to remove (drill out) those inserts for a friend who wanted to go back to the larger diameter OEM bolts.
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Old Mar 13, 2018 | 09:33 AM
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Originally Posted by Tom454
If someone purchased & installed the spring kit that includes bolt inserts (helicoils) to reduce the bolt size (for a larger width spring), that may come into play as well. I had to remove (drill out) those inserts for a friend who wanted to go back to the larger diameter OEM bolts.

I have done that very thing but I used keen serts.
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Old Mar 13, 2018 | 10:50 PM
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Originally Posted by cagotzmann
You need to do a few measurements first.

1. Width of the original spring Either 2.5" or 2 1/4"(FE7)
2. The diff housing mounting width for the spring. Could be 2.5" or 2 1/4".
3. The width of the lower mounting plate. again 2.5" or 2 1/4"

if your diff is 2.5" mounting then the lower plate needs to be 2.5" and use these to make up the space between the spring and the mounting bolts.

https://www.ecklerscorvette.com/1978...e7-option.html



You need to make sure the diff and lower plate are a match. either 2.5" or 2 1/4" Then measure the spring width. If the spring is 2.5" then no side plates / spacers are required. If the spring is 2 1/4" then you need the spacers.


Upper and lower spacers for a steel spring (OEM) I don't recall seeing one on my 78. When I changed to the VB&P mono spring I used the supplied spacer on the top only.

Also you may need to provide factory heat shield to protect the mono spring or wrap the exhaust.
Are the spacers installed in the picture you've attached? Also, what do you mean by supplied spacer? Do you not have the thick plastic block on top, a rubber pad, the spring, then another rubber pad? My concern is that the overall thicknesses of the old spring is a little greater than this new one. I am also almost positive that all VBP composite springs are 2.25", and my stock one was 2.5". The gap on either side also gives it away. I am thinking that I could buy a 1/8" sheet of aluminum and try to cut it to size. I just don't know how I'd keep it in place from sliding out.

I guess VBP isn't concerned with the gap, because they didn't mention it when I called, and there is nothing about it in the instructions I got. They told me to torque the three bolts to 45 ft lbs, which I guarantee will distort this plate- especially with the 1/8" gaps on both sides. I just wanted to get some input from the community before I try and reinvent the wheel here.

Last edited by garrettb; Mar 13, 2018 at 10:52 PM.
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Old Mar 14, 2018 | 10:20 AM
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Originally Posted by garrettb
Are the spacers installed in the picture you've attached? I could buy a 1/8" sheet of aluminum and try to cut it to size. I just don't know how I'd keep it in place from sliding out.
You cannot see the supplied spacer from VB&P because of the side spacers to make up the spring width from 2 1/4" to 2.5"

But the upper spacer should already be attached to the spring from VB&P. Its glued on the spring. No additional (loose) spacers where used.

Hard to see from the pictures but below is a link to FE7 spring spacers. They have a curve at the ends that match the mounting bolts spacing so they cannot slide out.

http://www.mamotorworks.com/Corvette...ption-624710-1

https://www.zip-corvette.com/77-79-r...e-spacers.html
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Old Mar 14, 2018 | 01:28 PM
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Originally Posted by cagotzmann
You cannot see the supplied spacer from VB&P because of the side spacers to make up the spring width from 2 1/4" to 2.5"

But the upper spacer should already be attached to the spring from VB&P. Its glued on the spring. No additional (loose) spacers where used.

Hard to see from the pictures but below is a link to FE7 spring spacers. They have a curve at the ends that match the mounting bolts spacing so they cannot slide out.

http://www.mamotorworks.com/Corvette...ption-624710-1

https://www.zip-corvette.com/77-79-r...e-spacers.html
Those spacers would work awesome if I had a pre-1980 spring mount. My plate only has three mounting bolts. I don't think those spacer plates would stay in place too well with no lateral support. Maybe they get squeezed by tightening the mounting plate? My other thought was to use some long bushings around the bolts to take up the gap, but that would only work in the rear. The front bolt is much shorter, and never contacts the spring.
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Old Mar 14, 2018 | 04:37 PM
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Originally Posted by garrettb
Those spacers would work awesome if I had a pre-1980 spring mount. My plate only has three mounting bolts. I don't think those spacer plates would stay in place too well with no lateral support. Maybe they get squeezed by tightening the mounting plate? My other thought was to use some long bushings around the bolts to take up the gap, but that would only work in the rear. The front bolt is much shorter, and never contacts the spring.
Sorry my mistake, I don't know why I thought you had a 78-79.

From the picture I see now the Alum Batwing diff support.

Yea my option will not work. Hopefully someone with the correct year can assist.
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