[PowerDemon]

Good morning all,

I’m looking to install BMR lowering springs and the BMR cradle lockout on my car. I was going to attempt the install myself in the garage but I came across a thread highlighting the importance of “timing” the bushings when doing the spring swap.

I had never come across this before, but it makes sense. For those that don’t know you’re supposed to leave all the suspension bolts loose while you lower the car to ride height and then tighten everything down so that the bushings are “neutral” and not in a bind at ride height.

My question is have any of you with lowering springs done that? I can’t imagine it makes a huge difference as the BMR springs only lower the car about 0.4”. For me, having to do this is the difference between taking it to a shop and doing it myself. I don’t really want to have it teetering on jackstands while trying to figure it out.

Thanks!

[WhiteMale]

Originally Posted by PowerDemon

Good morning all,

I’m looking to install BMR lowering springs and the BMR cradle lockout on my car. I was going to attempt the install myself in the garage but I came across a thread highlighting the importance of “timing” the bushings when doing the spring swap.

I had never come across this before, but it makes sense. For those that don’t know you’re supposed to leave all the suspension bolts loose while you lower the car to ride height and then tighten everything down so that the bushings are “neutral” and not in a bind at ride height.

My question is have any of you with lowering springs done that? I can’t imagine it makes a huge difference as the BMR springs only lower the car about 0.4”. For me, having to do this is the difference between taking it to a shop and doing it myself. I don’t really want to have it teetering on jackstands while trying to figure it out.

Thanks!

This is exactly what's on my mind right now. I'm more than able to install springs but this clocking of bushings for such a minimal change has cause me to rethink it. I'm pretty OK with toe plates too on my own.

[XXX ZL1]

Originally Posted by PowerDemon

Good morning all,

I’m looking to install BMR lowering springs and the BMR cradle lockout on my car. I was going to attempt the install myself in the garage but I came across a thread highlighting the importance of “timing” the bushings when doing the spring swap.

I had never come across this before, but it makes sense. For those that don’t know you’re supposed to leave all the suspension bolts loose while you lower the car to ride height and then tighten everything down so that the bushings are “neutral” and not in a bind at ride height.

My question is have any of you with lowering springs done that? I can’t imagine it makes a huge difference as the BMR springs only lower the car about 0.4”. For me, having to do this is the difference between taking it to a shop and doing it myself. I don’t really want to have it teetering on jackstands while trying to figure it out.

Thanks!

My OCD is over the top so I lossened the bolts after sitting it on 4 ramps to take the load off the bushings. Just remember all the suspension bolts are single use torque to yield.

[cdb95z28]

Originally Posted by PowerDemon

Good morning all,

I’m looking to install BMR lowering springs and the BMR cradle lockout on my car. I was going to attempt the install myself in the garage but I came across a thread highlighting the importance of “timing” the bushings when doing the spring swap.

I had never come across this before, but it makes sense. For those that don’t know you’re supposed to leave all the suspension bolts loose while you lower the car to ride height and then tighten everything down so that the bushings are “neutral” and not in a bind at ride height.

My question is have any of you with lowering springs done that? I can’t imagine it makes a huge difference as the BMR springs only lower the car about 0.4”. For me, having to do this is the difference between taking it to a shop and doing it myself. I don’t really want to have it teetering on jackstands while trying to figure it out.

Thanks!

To answer your question, When I did drop springs on my Gen5, yes, I timed the bushings that needed it. This means all rubber bushings. My Gen5 1LE had some rubber and some spherical type rose joints. The rose joints do not need timed. Certain models of the Gen6 have more rose joints than others. The ZL1, Zl1 1LE and SS 1LE have many rose joints.

Coming from the Gen5 community and now as a Gen6 SS 1LE owner, I see less conversations about timing the bushings among the Gen6 groups. I'm willing to bet most guys doing springs haven't done it. GM calls out timing the bushings in the service manual as tightening the suspension joints at ride height. So this is something that is not important. Yeah, it adds time and cost to just doing drop springs but do it once, do it right.

[WhiteMale]

TO add a wrinkle the OP says Jack stands and you can't time bushings on jackstands you'd need wheel cribs or a lift. Just another reason I'm probably going to waive off of lowering springs. And then this TTY bolts. Its great to really know what you're getting in to!

[cdb95z28]

https://www.camaro5.com/forums/showthread.php?t=153188

https://www.google.com/search?q=timi...1&dpr=0.8#ip=1

[1sickzl1]

What I've done in the past on my last car is once my car is jacked up on stands I used my floor jack to load the suspension and then loosen and re-torque to spec. I do one side a time. Then I get it re-aligned.

[PowerDemon]

Thanks for the info guys. Does anyone have the pages from the service manual needed for a spring change? I haven’t bought the service manual yet. I’m thinking about picking up the ACDelco subscription for long enough to download the info I need. Hopefully that will highlight which bushings need to be timed and which TTY bolts I need to purchase.

Has anyone done this on jackstands? Does the car need to be perfectly level?

[cdb95z28]

To get perfect static ride height, the car should be as close to level as possible.

I have the service manual info. I'll share it sometime today. When I did my AC Delco TDS I downloaded over 1200 pages just on the Gen6 alone. I did all my other GM vehicles at the same time. Best $20 I ever spent.

[cdb95z28]

From what I've found, the only rubber suspension bushings are:

At the rear:
-Every joint on the knuckle except the lower control arms and toe rods
-Upper and lower trailing arms at the subframe
-Lower control arm at subframe
-Anti roll bar mounting at the subframe. These bushings are actually glued to the bar and there is no way to loosen the bushings from the bar to time them to a new ride height.

At the front:
-Radius rod at the subframe. This is the forward diagonal arm.
-Anti roll bar mounting at the subframe. Same explanation above as the rear anti roll bar


If not mentioned above, then they are rose joint type joints which have no inherent bind. These are similar to spherical joints and they can rotate and re-center to a new static ride height.

The fastener torque spec files show which fasteners are to be replaced.

FRONT MAGRIDE STRUT.pdf

MAGRIDE SPRING.pdf

MAGRIDE STATIC HEIGHT RECAL.pdf

REAR SPRING.pdf

SUSPENSION FRONT FASTENER TORQUE SPECS.pdf

SUSPENSION REAR FASTENER TORQUE SPECS.pdf

FRONT CAMBER ADJUSTMENT.pdf

ABS FASTENER TORQUE SPECS.pdf

BRAKE SYSTEM ADHESIVES AND LUBRICANTS.pdf

BRAKE SYSTEM FASTENER TORQUE SPECS.pdf

[PowerDemon]

Man thank you that is excellent information. I really appreciate you posting all that.