Upgrading Z51 to GS/Z06 leaf spring?
12-21-2018, 10:14 AM
#41
Really? I find the Z51s to be very neutral compared to most cars
12-21-2018, 10:22 AM
#43
Tech Contributor
Thread Starter
12-22-2018, 08:53 PM
#45
Team Owner
Member Since: Jan 2007
Location: cookeville tennessee
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For starters, I think 245/255 is very small for ANY C7 Corvette (and even C6, C5, etc.). When I started modding my C7 Z51 for better track performance, the biggest change in performance came from switching my fronts from 275s to 315s. This was in fact the reason why I switched to coilovers, since the much-increased front bite made the car feel like a boat with OEM Z51 springs and T1 sways/shocks. In other words, I'd highly recommend switching to 315 or similarly wide fronts for track use for any C7, which would necessitate much stiffer sway bars or springs for Z51 for sure.
01-01-2019, 10:05 PM
#46
Tech Contributor
Thread Starter
Heads up if you haven't seen my thread on the road racing section, I installed GS/Z06 springs . Currently Using z51 stock msrc calibration with no problems on country roads. Will need to see how it reacts on track.
Heres the crude instructions:
FRONT spring replacement:
you have to follow the gm write up and remove the alignment bolts to drop the inner side of the lower control arm. Then it's easy so:
On one side:
1 Remove wheel
2 Remove caliper
3 Put jack under spring near LCA and raise it off the LCA
4 Disconnect wheel travel sensor from LCA
5 Remove steering knucle attachment
6 Remove sway bar attachment
7 Remove lower shock bolts Drop inner side of control arm.
8 remove spring retaining brackets. while working the control arm around the spring, slowly lower jack to loosen spring.
9 Adjust lowering bolts on new spring, it's going to need to be about 1 inch lower to match the z51 spring to keep ride height the same.
10 Put in on built wheel side first and attach springbrackets loosely.
11 Raise open edge of spring over the LCA and repeat the other steps backwards.
12 To put LCA back in, make sure you jack it up exactly below the spring ride height pads.
REAR spring replacement:
So here is what I did to replace the rear leaf spring: Buy an extra eccentric cam alignment bolt. Part# 11611443
1 Raise on jack stands.
On one side only:
2 Remove wheel
3 remove brake cooling deflector
4 Remove brake caliper and put somewhere safe
5 Unbolt wheel speed sensor and put by caliper
6 unhook sway bar link
7 Remove lower shock bolt
8 MARK both sides of the lower control arm cams and the cams on the tie rod.
9 Unbolt inboard cam bolt on tie rod.
10 Jack up slightly and support the knuckle/rotor (I used a small tool box). Make sure this won't tip over as you'll be wrestling around with the assembly.
now use the jack to jack up the leaf spring as far outboard as possible. Just enough to remove pressure from lower control arm.
11 Unbolt the upper control arm. 4 bolts .Make sure you don't lose the washers. Keep them in order and orientation.
12 Unbolt the spring retainer brackets below the car.
13 Unbolt the lower control arm 2 cam bolts. The front one won't come off, you'll need to cut it off with a sawzall (new bolt will go in facing the other direction).
Now the lower control arm is loose ish.
14 You'll need to use a thin pry bar to pry the lower control arm around the cross member and down. MAKE SURE NOTHING IS HANGING UP. I DID THIS WITH MY WHEEL SPEED SENSORAND ALMOST RIPPED IT APART. Once the lower control arm has dropped lower the jack holding the spring. It should be free now.
15 Work the spring out towards the unassembled side.
16 Adjust ride height pads to match on new spring. My rear sat 3/4" lower with the same spring pad setup. So make the new spring pads that much taller (I liked it better so I left it).
Assembly was easier. Just reverse steps. Make sure to put aligment cams back. Don't forget to torque everything. Hardest part was pulling the lower control arm around the cross member brackets. Putting it back in was easy.
HERE IS THE VERY IMPORTANT PROBLEM THAT WILL HAPPEN: The half shafts will come out as you're pulling the knuckle fairly far. You'll know this because the upper control arm won't go back in place. So save headaches and check on it before reassembly: Jack up bottom of knucle until the car just about raises off the stands. Now spin the half shaft and feel until you can get it pushed in. It's a good 2 inches of travel so you'll know when you got it. Don't take the dust boots off to look(I had to, had no idea what was back there) as getting them back on with all that grease was veeeeery annoying and you have to replace the clamps.
Heres the crude instructions:
FRONT spring replacement:
you have to follow the gm write up and remove the alignment bolts to drop the inner side of the lower control arm. Then it's easy so:
On one side:
1 Remove wheel
2 Remove caliper
3 Put jack under spring near LCA and raise it off the LCA
4 Disconnect wheel travel sensor from LCA
5 Remove steering knucle attachment
6 Remove sway bar attachment
7 Remove lower shock bolts Drop inner side of control arm.
8 remove spring retaining brackets. while working the control arm around the spring, slowly lower jack to loosen spring.
9 Adjust lowering bolts on new spring, it's going to need to be about 1 inch lower to match the z51 spring to keep ride height the same.
10 Put in on built wheel side first and attach springbrackets loosely.
11 Raise open edge of spring over the LCA and repeat the other steps backwards.
12 To put LCA back in, make sure you jack it up exactly below the spring ride height pads.
REAR spring replacement:
So here is what I did to replace the rear leaf spring: Buy an extra eccentric cam alignment bolt. Part# 11611443
1 Raise on jack stands.
On one side only:
2 Remove wheel
3 remove brake cooling deflector
4 Remove brake caliper and put somewhere safe
5 Unbolt wheel speed sensor and put by caliper
6 unhook sway bar link
7 Remove lower shock bolt
8 MARK both sides of the lower control arm cams and the cams on the tie rod.
9 Unbolt inboard cam bolt on tie rod.
10 Jack up slightly and support the knuckle/rotor (I used a small tool box). Make sure this won't tip over as you'll be wrestling around with the assembly.
now use the jack to jack up the leaf spring as far outboard as possible. Just enough to remove pressure from lower control arm.
11 Unbolt the upper control arm. 4 bolts .Make sure you don't lose the washers. Keep them in order and orientation.
12 Unbolt the spring retainer brackets below the car.
13 Unbolt the lower control arm 2 cam bolts. The front one won't come off, you'll need to cut it off with a sawzall (new bolt will go in facing the other direction).
Now the lower control arm is loose ish.
14 You'll need to use a thin pry bar to pry the lower control arm around the cross member and down. MAKE SURE NOTHING IS HANGING UP. I DID THIS WITH MY WHEEL SPEED SENSORAND ALMOST RIPPED IT APART. Once the lower control arm has dropped lower the jack holding the spring. It should be free now.
15 Work the spring out towards the unassembled side.
16 Adjust ride height pads to match on new spring. My rear sat 3/4" lower with the same spring pad setup. So make the new spring pads that much taller (I liked it better so I left it).
Assembly was easier. Just reverse steps. Make sure to put aligment cams back. Don't forget to torque everything. Hardest part was pulling the lower control arm around the cross member brackets. Putting it back in was easy.
HERE IS THE VERY IMPORTANT PROBLEM THAT WILL HAPPEN: The half shafts will come out as you're pulling the knuckle fairly far. You'll know this because the upper control arm won't go back in place. So save headaches and check on it before reassembly: Jack up bottom of knucle until the car just about raises off the stands. Now spin the half shaft and feel until you can get it pushed in. It's a good 2 inches of travel so you'll know when you got it. Don't take the dust boots off to look(I had to, had no idea what was back there) as getting them back on with all that grease was veeeeery annoying and you have to replace the clamps.
Last edited by BrunoTheMellow; 01-01-2019 at 10:09 PM.
The following 4 users liked this post by BrunoTheMellow:
08-19-2019, 07:28 PM
#47
Tech Contributor
Heads up if you haven't seen my thread on the road racing section, I installed GS/Z06 springs . Currently Using z51 stock msrc calibration with no problems on country roads. Will need to see how it reacts on track.
Heres the crude instructions:
FRONT spring replacement:
you have to follow the gm write up and remove the alignment bolts to drop the inner side of the lower control arm. Then it's easy so:
On one side:
1 Remove wheel
2 Remove caliper
3 Put jack under spring near LCA and raise it off the LCA
4 Disconnect wheel travel sensor from LCA
5 Remove steering knucle attachment
6 Remove sway bar attachment
7 Remove lower shock bolts Drop inner side of control arm.
8 remove spring retaining brackets. while working the control arm around the spring, slowly lower jack to loosen spring.
9 Adjust lowering bolts on new spring, it's going to need to be about 1 inch lower to match the z51 spring to keep ride height the same.
10 Put in on built wheel side first and attach springbrackets loosely.
11 Raise open edge of spring over the LCA and repeat the other steps backwards.
12 To put LCA back in, make sure you jack it up exactly below the spring ride height pads.
REAR spring replacement:
So here is what I did to replace the rear leaf spring: Buy an extra eccentric cam alignment bolt. Part# 11611443
1 Raise on jack stands.
On one side only:
2 Remove wheel
3 remove brake cooling deflector
4 Remove brake caliper and put somewhere safe
5 Unbolt wheel speed sensor and put by caliper
6 unhook sway bar link
7 Remove lower shock bolt
8 MARK both sides of the lower control arm cams and the cams on the tie rod.
9 Unbolt inboard cam bolt on tie rod.
10 Jack up slightly and support the knuckle/rotor (I used a small tool box). Make sure this won't tip over as you'll be wrestling around with the assembly.
now use the jack to jack up the leaf spring as far outboard as possible. Just enough to remove pressure from lower control arm.
11 Unbolt the upper control arm. 4 bolts .Make sure you don't lose the washers. Keep them in order and orientation.
12 Unbolt the spring retainer brackets below the car.
13 Unbolt the lower control arm 2 cam bolts. The front one won't come off, you'll need to cut it off with a sawzall (new bolt will go in facing the other direction).
Now the lower control arm is loose ish.
14 You'll need to use a thin pry bar to pry the lower control arm around the cross member and down. MAKE SURE NOTHING IS HANGING UP. I DID THIS WITH MY WHEEL SPEED SENSORAND ALMOST RIPPED IT APART. Once the lower control arm has dropped lower the jack holding the spring. It should be free now.
15 Work the spring out towards the unassembled side.
16 Adjust ride height pads to match on new spring. My rear sat 3/4" lower with the same spring pad setup. So make the new spring pads that much taller (I liked it better so I left it).
Assembly was easier. Just reverse steps. Make sure to put aligment cams back. Don't forget to torque everything. Hardest part was pulling the lower control arm around the cross member brackets. Putting it back in was easy.
HERE IS THE VERY IMPORTANT PROBLEM THAT WILL HAPPEN: The half shafts will come out as you're pulling the knuckle fairly far. You'll know this because the upper control arm won't go back in place. So save headaches and check on it before reassembly: Jack up bottom of knucle until the car just about raises off the stands. Now spin the half shaft and feel until you can get it pushed in. It's a good 2 inches of travel so you'll know when you got it. Don't take the dust boots off to look(I had to, had no idea what was back there) as getting them back on with all that grease was veeeeery annoying and you have to replace the clamps.
Heres the crude instructions:
FRONT spring replacement:
you have to follow the gm write up and remove the alignment bolts to drop the inner side of the lower control arm. Then it's easy so:
On one side:
1 Remove wheel
2 Remove caliper
3 Put jack under spring near LCA and raise it off the LCA
4 Disconnect wheel travel sensor from LCA
5 Remove steering knucle attachment
6 Remove sway bar attachment
7 Remove lower shock bolts Drop inner side of control arm.
8 remove spring retaining brackets. while working the control arm around the spring, slowly lower jack to loosen spring.
9 Adjust lowering bolts on new spring, it's going to need to be about 1 inch lower to match the z51 spring to keep ride height the same.
10 Put in on built wheel side first and attach springbrackets loosely.
11 Raise open edge of spring over the LCA and repeat the other steps backwards.
12 To put LCA back in, make sure you jack it up exactly below the spring ride height pads.
REAR spring replacement:
So here is what I did to replace the rear leaf spring: Buy an extra eccentric cam alignment bolt. Part# 11611443
1 Raise on jack stands.
On one side only:
2 Remove wheel
3 remove brake cooling deflector
4 Remove brake caliper and put somewhere safe
5 Unbolt wheel speed sensor and put by caliper
6 unhook sway bar link
7 Remove lower shock bolt
8 MARK both sides of the lower control arm cams and the cams on the tie rod.
9 Unbolt inboard cam bolt on tie rod.
10 Jack up slightly and support the knuckle/rotor (I used a small tool box). Make sure this won't tip over as you'll be wrestling around with the assembly.
now use the jack to jack up the leaf spring as far outboard as possible. Just enough to remove pressure from lower control arm.
11 Unbolt the upper control arm. 4 bolts .Make sure you don't lose the washers. Keep them in order and orientation.
12 Unbolt the spring retainer brackets below the car.
13 Unbolt the lower control arm 2 cam bolts. The front one won't come off, you'll need to cut it off with a sawzall (new bolt will go in facing the other direction).
Now the lower control arm is loose ish.
14 You'll need to use a thin pry bar to pry the lower control arm around the cross member and down. MAKE SURE NOTHING IS HANGING UP. I DID THIS WITH MY WHEEL SPEED SENSORAND ALMOST RIPPED IT APART. Once the lower control arm has dropped lower the jack holding the spring. It should be free now.
15 Work the spring out towards the unassembled side.
16 Adjust ride height pads to match on new spring. My rear sat 3/4" lower with the same spring pad setup. So make the new spring pads that much taller (I liked it better so I left it).
Assembly was easier. Just reverse steps. Make sure to put aligment cams back. Don't forget to torque everything. Hardest part was pulling the lower control arm around the cross member brackets. Putting it back in was easy.
HERE IS THE VERY IMPORTANT PROBLEM THAT WILL HAPPEN: The half shafts will come out as you're pulling the knuckle fairly far. You'll know this because the upper control arm won't go back in place. So save headaches and check on it before reassembly: Jack up bottom of knucle until the car just about raises off the stands. Now spin the half shaft and feel until you can get it pushed in. It's a good 2 inches of travel so you'll know when you got it. Don't take the dust boots off to look(I had to, had no idea what was back there) as getting them back on with all that grease was veeeeery annoying and you have to replace the clamps.
Is it not possible to just disconnect the two LCAs from the knuckes, rotate them down, and then slide the spring out? The below pic illustrates what I'm thinking. They were replacing the LCAs with T1 parts, but the point is how the LCAs are lowered and in theory the spring will slide right out since it wouldn't have a support under it like in the pic...
06-14-2023, 10:47 PM
#48
Intermediate
Hello,
I'm planning out my coilover install and will use these instructions to remove the stock springs and to R/R the shocks to the coilovers. Two questions from those of you who have removed the C7 oem springs as it is new to me (although I've installed shocks on a C6 before):
1) For the front spring, BrunoTheMellow wrote "you have to follow the gm write up and remove the alignment bolts to drop the inner side of the lower control arm". I can't seem to find an excerpt from a GM shop manual for this when I searched but are there any special steps I need to be aware of beyond removing the bolt and then removing and reinstalling the alignment eccentrics?
2) For the rear spring and it jacked up on one side to relieve spring tension on the lower control arm, is there any danger I need to be aware of with the spring is under tension while working on the upper and lower control arms?
Thank you!
I'm planning out my coilover install and will use these instructions to remove the stock springs and to R/R the shocks to the coilovers. Two questions from those of you who have removed the C7 oem springs as it is new to me (although I've installed shocks on a C6 before):
1) For the front spring, BrunoTheMellow wrote "you have to follow the gm write up and remove the alignment bolts to drop the inner side of the lower control arm". I can't seem to find an excerpt from a GM shop manual for this when I searched but are there any special steps I need to be aware of beyond removing the bolt and then removing and reinstalling the alignment eccentrics?
2) For the rear spring and it jacked up on one side to relieve spring tension on the lower control arm, is there any danger I need to be aware of with the spring is under tension while working on the upper and lower control arms?
Thank you!
06-14-2023, 11:10 PM
#49
Sr.Random input generator
(1) Fronts are easier to remove. Once you detach the sway bar endlinks and remove the LCA eccentric bolts, you should have enough space to get it out.
(2) When the suspension is in full droop, especially with endlinks, etc. detached, there will be little to no tension from the springs. Rear is a bit harder, but I was able to remove it (and also install it back later on) with help of a simple adjustable stand under my car lift.
(2) When the suspension is in full droop, especially with endlinks, etc. detached, there will be little to no tension from the springs. Rear is a bit harder, but I was able to remove it (and also install it back later on) with help of a simple adjustable stand under my car lift.