Rear spring replacement tips?

Suspension, brake, and hydraulic/electric steering discussion.
CrashTestDummy
Posts: 2300
Joined: Sat Feb 07, 2015 2:31 pm
Location: Pearland, Texas

Re: Rear spring replacement tips?

Post by CrashTestDummy »

cal30_sniper wrote:<SNIP>

I'm counting on the full spectrum of lifts, air tools, and shop spring compressors at the base hobby shop to make the job a bit easier. We shall see. I don't have anything pressing until tomorrow evening, so hopefully I can get an early start in the morning.

I've only dealt with torque to yield a few times in the past, but I've always used either the wrench handle, or the flats of the bolt head to figure out how many degrees it needed to turn. Wrench handles work great in 90 degree increments, and the flats on the bolt head work great for 60 degree increments. The problem I've always found with gorilla calibration on bolts is that people tend to way overdo it, and they can be a real nightmare to get off again after some usage cycles.
Heh, 'base hobby shop', I remember those!! My Dad used to take me to the one near Vandenberg when he was working on the Studebaker he was replacing a broken rear spring on (the reason he got it so cheap). Those were such great places.
Gene Beaird,
Pearland, Texas
2012 Caprice 9C1
1992 B4C 1LE Camaro
2018 Tahoe PPV (her car)
1995 DGGM Impala SS
1985 Firebird - 310 LS1 C Prepared autocross car.
1980 Bluebird Wanderlodge
And some others
Do YOU have my SPID?
cal30_sniper
Posts: 103
Joined: Thu Aug 04, 2016 1:17 pm

Re: Rear spring replacement tips?

Post by cal30_sniper »

CrashTestDummy wrote: Heh, 'base hobby shop', I remember those!! My Dad used to take me to the one near Vandenberg when he was working on the Studebaker he was replacing a broken rear spring on (the reason he got it so cheap). Those were such great places.
The one here at Cherry Point is great. Lots of tools, a bunch of lifts, and a full compliment of engine rebuild shop, tire shop, welding, and a bunch of other odds and ends. Definitely the nicest one I've ever been to. I do most of my work at home just because I have so many tools here and I never feel rushed, but for days like today, some of the specialty tools in the hobby shops really pay off.

I got the fronts done in about 2 hours today before knocking off for the afternoon. I plan to go back and do the rears tomorrow morning. I already noticed a huge improvement in ride quality on the 20 minute drive home.
-2011 Caprice 9C3: Mirage Glow Metallic, 63k miles
-2011 Caprice 9C1 (Gone)
-1973 Firebird Formula, restoration in progress
-1986 K30 Suburban 8.1L/NV4500, the toy hauler and wheeler
cal30_sniper
Posts: 103
Joined: Thu Aug 04, 2016 1:17 pm

Re: Rear spring replacement tips?

Post by cal30_sniper »

I finished the rear spring and shock swap on Sunday morning. It took 3 hrs from putting the car on the lift to taking it back down. The only air tools I used was an air gun to get the lug nuts off. I did have the luxury of access to a nice floor mounted spring compressor to do the actual spring swap itself.

All in all, it was much easier than I have read it made out to be. There were no prybars, or hammers, or cursing involved whatsoever. I learned a few tricks to make it easier while doing the first spring on the drivers side, which made the passenger side swap take about half the time. Here's a few tips:

1. As mentioned in numerous places, unbolt the lower control arm to knuckle bolt, the shock to control arm bolt, and the four bolts holding the shock top of the upper shock mount to the body.
2. Also disconnect the swaybar end link from the control arm. You can disconnect the upper or lower nut to do this. However, don't be an idiot like me. The plastic cap on the back is a GREASE CAP and DOES NOT POP OFF. Thanks to one of the threads I ran into on the G8 boards, I tried to pop it out thinking there was a torx head underneath it. It broke, was full of grease, and then I found the torx fitting on the inside of the THREAD end of the swaybar link end. All went smoothly after that, but I'll need a new end link on that side.
3. There is an order of removal for the shock/spring assembly that doesn't require any prying or other nonsense. First, lower the disconnected lower control arm as far as it will go, mine lowered with hand pressure alone until contacting the rear subframe rail. I would not recommend forcing it further than this, as you are bending frame metal at that point. Once the lower control arm is as low as it will go, lift the lower shock mounting point out of its channel in the lower control arm. Once it's clear of the lower control arm, you can pivot the entire strut assembly down and out of it's pocket in the vehicle body. After that, it's smooth removal. On the drivers side, I pulled the top out of the pocket first, and then tried to remove the lower part of the shock from its channel. Working in this order, I couldn't remove the shock/strut assembly until after I had taken off the brake caliper and moved it out of the way. On the passenger side, I removed the bottom of the shock first and didn't need to remove the brake caliper to clear it.
4. The spring swap itself is self explanatory. Just make sure you transfer the rubber isolaters to the new shock, along with the upper shock mount. Make sure to mark the orientation of the lower shock mounting axis to the upper shock mount. The new shock/spring/mount needs to be assembled in the same orientation. Once the spring pressure is on and the upper nut is torqued, you won't be able to rotate the lower shock mounting point to match the angle of the lower control arm holes.
5. For reassembly, I found it works best to install the lower control arm to knuckle bolt first, then thread the two upper shock mount to body bolts on the inboard side until they are just started, leaving plenty of shank to wiggle the shock mount around. Once those two are threaded, then install the lower shock to control arm bolt. Once it's through the shock and control arm, start tightening the two inboard shock mount to body bolts until they draw the top of the shock mount close enough to the body to install the outboard bolts. Then tighten all four of the bolts to their final torque specs. I lightly tightened the lower control arm to shock and LCA to knuckle bolts, and then raised the car on and off the lift a few times to set the body weight on the suspension. Then, with the wheels on the ground and unsupported by the lift, I crawled underneath and torqued the rest of the bolts (I'm a skinny guy. A larger guy would need to figure out someway to block the tires up off the ground to make space underneath. A drive on lift would also work great. There's plenty of room with the wheels installed to still access the bolts that need to be torqued).
6. Final tip: Mark everything with a paint or grease pen before you take it out. With the outline of where the old upper shock mounts were relative to the body, none of your rear alignment specs should change. The same works on the front suspension strut to knuckle interface.

Not as easy as swapping the shocks on an older car, but definitely not the huge hassle it's often made out to be either. The 12-13 Caprice shocks and 14 SS Sedan springs made a huge difference on my car. It no longer looks like a 4x4, and the ride is much less jarring. I only wish I'd done the swap sooner.
-2011 Caprice 9C3: Mirage Glow Metallic, 63k miles
-2011 Caprice 9C1 (Gone)
-1973 Firebird Formula, restoration in progress
-1986 K30 Suburban 8.1L/NV4500, the toy hauler and wheeler
smwalker
Administration Staff
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Joined: Mon Jul 29, 2013 1:44 am
Location: Azusa,CA

Re: Rear spring replacement tips?

Post by smwalker »

Cal30, how many miles did you have on the ones you took out? You replace any of the extra rubber and bumper stuff? Lot of wear? Got 40K on mine wondering if I should do a complete replacement of all parts just for good measure?
Steve Walker
Azusa, CA
'11 PPV 9C3 Huron White
cal30_sniper
Posts: 103
Joined: Thu Aug 04, 2016 1:17 pm

Re: Rear spring replacement tips?

Post by cal30_sniper »

Mine just turned 17k non-duty miles this weekend. All the rubber stuff, bushings, etc were in great shape. I ordered new fasteners for the knuckle and strut bolts just because mine were rusty, but other than that, reused all the factory stuff. Only real issue I had was one of the front upper strut mount bearing assemblies came open while I was putting the strut assembly back together. I caught all the ball bearings, cleaned them, greased them, and put it back together. Might be worth new upper strut mounts on a 40k mile car.
-2011 Caprice 9C3: Mirage Glow Metallic, 63k miles
-2011 Caprice 9C1 (Gone)
-1973 Firebird Formula, restoration in progress
-1986 K30 Suburban 8.1L/NV4500, the toy hauler and wheeler
CrashTestDummy
Posts: 2300
Joined: Sat Feb 07, 2015 2:31 pm
Location: Pearland, Texas

Re: Rear spring replacement tips?

Post by CrashTestDummy »

It's been mentioned before, and I'll reiterate; one should always get new upper mount kits when doing this work because of what you experienced. 99% of the time, this assembly will explode when you decompress the strut compressor, disgorging it's contents all over your garage. Finding all of the bearings is not always possible.

I experienced that situation when I was installing my coil-overs. I _thought_ I had a complete kit, but discovered the missing pieces when the first strut was already out of the car. Like you, I was lucky enough to find all of the bearings (you know you have them all when there are no gaps in the ring of bearings in the housing). Instead of re-using the old bearing, though, I kept it as a backup and went and got a new strut installation kit for both sides. The parts house had one in stock, and another in the warehouse that I got a couple of hours later.

Our car had ~86K miles on it, though, so I was already planning on replacing all of the mount parts, even though the bearings (even the 'rebuilt' one I did) felt smooth to turn.
Gene Beaird,
Pearland, Texas
2012 Caprice 9C1
1992 B4C 1LE Camaro
2018 Tahoe PPV (her car)
1995 DGGM Impala SS
1985 Firebird - 310 LS1 C Prepared autocross car.
1980 Bluebird Wanderlodge
And some others
Do YOU have my SPID?
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