Preparing the independent rear suspension for installation
This post covers independent rear suspension installation prep. After the front work, the IRS is next on kit #9772.
Related notes live on the Factory Five Cobra build hub.
independent rear suspension installation: IRS parts overview
Now that the basic front install is done, it’s time to tackle the IRS setup. First, several components make up the IRS.
- 3.55 8.8 Super Differential Center Section
- 2 Half-Shaft/Axles
- 2 Spindles + 2 Hubs
- Toe Adjustment Arms
- Upper Control Arms
- Lower Control Arms
All these bits plant the rear tires on the ground. Also, they deliver power equally via the Traction-Lok differential. Normally, Factory Five offers this as an option. However, for the 25th Anniversary car, it’s a standard component.
The manual has ~60 pages covering installation. That’s about double the work of the independent front suspension. I purchased the differential, spindles, and hubs from Mike Forte back in December.
Drill the spindles and center section
First steps are to prepare the aluminum spindles and differential. I had to purchase a 5/8″ drill bit. Not very common in your average toolbox. Still, about $15. I’m not complaining. Meanwhile my wrists got a workout!
Cut the spindle ears
Next, the “ears” of the spindles need to be cut off. Because the stock spindles won’t fit FFR geometry without modification. Draw a simple line from the hole on top to the bump on the bottom.
Using a Sawzall takes time. However, you eventually get through. My best option was a 14TPI metal blade. Also, I used some oil to lubricate the cut.
Hub studs, arms, and paint
The hubs need some pre-work as well. First, knock out the Mustang studs. Simple hammer and vice work. Then press the new studs into place. An impact drill or stationary press both work.
Mount hubs, UCAs, and LCAs
Next was to mount the hubs on the spindles. Then start assembly of the toe, UCA, and LCA. Some parts are still missing from FFR. So I can’t fully complete the installation yet. Still, it’s 99% there!
Paint the half-shafts
To finish up some items, I decided to spray paint the half-shaft/axles. Therefore they stay protected from rust.
And here are all the parts. Meanwhile I’m waiting on a few bits to finalize. FFR shipped the missing items. Ultimately it will all go together quickly!
