A simple method of replacing rear strut cushions

[docjim]

Wil Hodges (AKA ShowZ) is a mechanical genius! Apparently, removing the spindle pin can be a real b**ch. His method avoids having to pull the pin.

He sent me an e-mail outlining a procedure for replacing the strut cartridges. Here is my adaption of his method:
1. Chock the front wheels securely.
2. Jack up the rear axle at least 15” off the floor. This was as high as my cheap jack could lift it without placing boards under the jack.
3. Place jack stands securely under the rear axle bar. I’ll post pictures tomorrow if anybody is interested.
4. Remove the wheels and brake drum. You’ll have to release the parking brake, of course.
5. Remove the brake line and parking brake pin at the drum.
6. Remove the 4 bolts holding the axle stub at the outer housing joint.
7. Place a jack under the a-arm and disconnect the sway bar to a-arm assembly.
8. Remove the top 3 nuts (inside the car).
9. Lower the jack. Then, in my case lift the a-arm enough to remove the jack.
10. Rotate the strut outward.
11. Now is the time to compress the spring and disassemble the strut assembly.

Since I was going to replace the BMW 3-series springs, I just used a cut off blade to slice the spring into a few pieces. Then, I held up the top spring with a pair of vise grips and used a large pipe wrench to remove the strut cartridge holding nut. (Note: This can be messy if the previous person followed directions and poured the oil into the strut housing.) Once I had the cartridge out, I could remove the top nut and get the rest of the assembly apart by clamping the cartridge rod into the pipe gripper part of my vise.

What wasn’t part of my description was the removal of the adjusters Wil had made. This involved the cut off blade, hammer and chisels, and a lot of sweat. The BMW springs were much shorter than the Z springs, so when I cut them, I could separate the pieces and gain access to the cartridge holding nut.

Assembly was pretty much the reverse of the procedure. However, since Wil had already cut the top off th Z and “convertiblized” it, there was only a small opening between the trunk and the top of the strut tower. This made aligning the 3 bolts with the 3 holes fun, since I couldn’t see down the holes to see where the bolts were. I finally painted the top of the 3 bolts and used a small inspection mirror and flashlight to see a little ways down the holes and find the bolts.

Finally, I breathed a sigh of relief, thanked God, and took a shower.

 

Jim

[Six_Shooter]

Is that not how most people replace springs in these cars?

 

I have yet to pull my spindle pins in my car and have had my suspension out a few times for different reasons, though I have one modification in mind that would necessitate it. 

[RebekahsZ]

Jack up rear of car and put on jackstands.

Remove wheel.

Remove axle.

Disconnect brake line and parking brake pin.

Remove little crossmber under the diff.

Put jack under hub

Remove strut insulator from chassis and put the corner on the floor.

Install spring compressor

Remove insulator nut with impact wrench.

Reverse to reassemble

Bleed brakes.

 

With disc brakes you don't have to bleed brakes.

With coilovers you don't have to drop the corner, you remove the axle, remove the caliper and let it hang on the flex line, lower the spring seat all the way, drop the strut from the chassis, compress the shock with your hand and swing the assembly out like an oven door. Air impact wrench the top nut off and swap the spring.

[NewZed]

Loosen the center strut rod nut before doing anything else.  A socket wrench will work, no vises or impact wrenches required.

[Miles]

I do mine with a few less steps:

 

• Put car on jack stands.
• Disconnect the brake lines and parking brake cables.
• Remove the three nuts on the insolater cap holding the strut assembly to the shock tower.
• There is enough slop in the suspension that you can just put your foot on the hub and push down on it while pulling the strut towards you to clear the fender lip. No need to remove any other parts.
• Apply spring compressor and remove the nut on the shock.
• Replace springs/shocks as required.
• Reverse steps to reassemble.

I installed Arizona Z springs on two 240Zzs this way. The Arizona Z springs were shorter than the stock springs so a spring compressor was not required for reinstallation.  Seems like it took about twenty minutes per corner.

[NewZed]

For those with 280Z's - the rear strut assembly is too long, longer than the early S30's, to slip out from under the fender well without loosening the inner rear control arm bolts, unless you put a lot of pressure on it.  The 240Z's do seem easier to get done.

 

On the nut - you can stick a bar or long screwdriver between the three studs to get leverage, with the strut assembly out or dropped. It's shown that way in the FSM's.   Or dill two holes in a piece of steel to set over two studs.  

 

Everyone's got their own little tricks and most depend on what tools you have available.  Some let the stock springs fly when replacing with shorter springs, if they don't have a spring compressor..

[Six_Shooter]

I have a '73 and was not able to get the strut assembly to swing down enough to clear the fender lips.