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Installation Instructions for IF-4852FPT Mustang II IFS for 1948-1952 Ford Truck

Installation Instructions for IF-4852FPT Mustang II IFS for 1948-1952 Ford Truck

Posted by Jeanne Lewis on 2nd Jun 2017

IF-4852FPT Mustang II IFS for 1948-1952 Ford Truck

Chassis Engineering Installation Instructions for IF-4852FPT Mustang II IFS for 1948-1952 Ford Truck


1: Remove the original front suspension.

Straighten the edges and lips on the frame where the new cross member and support rods will be placed.

Make sure the frame edges are a straight 90 degrees from the side of the frame.

Remove any rivet heads that might interfere with proper fitting of the cross member. Grind these flush with the frame.

2: Bolt the new lower cross member to the bottom of the frame using the dimensions below:


The steering mounts on the cross member point to the front.


Measure from the center of the original front spring mount to the front of the new cross member.

3: Place the coil spring pods over the frame and line them up with the lower cross member.

The pods will only fit one way, and the taller side needs to be on the front.


Check for clearance between the frame and the new parts. Make the modifications needed to correct anything that will interfere with a proper fit.

At this point, performing a wheel centering check is recommended. While there are normally no issues with this, it never hurts to check to make sure you don't run into anything further into your build. Assemble the A-arms and spindle on one side, without a spring in place, and installing a wheel. Now look it over to make sure it is centered.

While rare, if there is an issue with centering, the cross member can be moved slightly to correct this.

4: Now clamp the upper and lower pieces together in the location where it needs to be. Again, check and make sure nothing is causing any fitting issues.

Drill the 8 holes per side, vertical holes first, and bolt it all together tightly.

The cross member, the frame and the coil spring pods should now be firmly attached together.

5: Strut Rod Support Brackets

Straighten the frame edges, where the strut rod support brackets will sit, to a straight 90 degrees angle.


Put a bracket in place around the frame and insert a bolt in the center brace to the crossmember tube. Now fit the bracket to the frame and find the spot where it has the best fit. Do both sides, and compare the measurements. Average these to make the brackets on both sides the same. Now clamp them in place.

Note: brackets will only fit the frame properly if the edges are properly straight.

6: Drill the holes underneath the frame first, making sure that the brackets sit flush with the outside frame. Then do the outside holes and bolt things together as you go.

7: The IF-4852FPT (this kit) comes with two rack extensions. These are needed to move the tie rod inner pivot outward. If these extensions are not used, you will likely run into steering issues. The kit is 2 inches wider than a stock Pinto one, and these spacers are critical to keep the geometry the same.

Make sure that these extensions are locked to both the rack and the tie rod.


There are multiple solutions for this, but we recommend drilling a 1/8" hole drilled half-way through the extension and the original shaft, and a roll pin driven in to act as a lock.

Note: The spacers/extensions included are for an original standard steering and pinion setup. If you are using power steering or have an aftermarket replacement rack installed, then contact us before ordering.

8: Install components from 1974-1978 Pinto or 1974-1978 Mustang II to complete installation. We recommend manual steering. Use Pinto struts, and not struts from Mustang II. Use a new strut bushing set. See Ford or front end manuals for installation instructions covering the A-arms, Strut Rods, Springs, Shocks and the line-up specs.

9: Coil springs needs to be cut to 12" height. If you use our Chassis Engineering coil springs then they already are properly sized. We have springs available in 25lbs increments (link).

10: For safety, always use jack stands whenever you may be working underneath your ride.

For height adjustment, start with taking off all the weight off of the springs. Jack the front wheels off of the ground and (possibly) unhooking the shocks.

Loosen the 1/4" locking set screw and turn the height adjuster to its new position.


You can use this adjustment to raise or lower the car, however, it is intended to compensate for different springs.

To make this adjustment a breeze, we have a custom IFS adjustment wrench (IF-0000W)


For correct geometry, the lower A-arm should be parallel to the ground. Line-up groove in threads and retighten the locking set screw.

11: On a "fresh" car with a new IFS setup, after some good road miles, check the coil springs for proper setting. New springs settle after a while, so it is a good idea to check if adjustments are needed to make sure the lower control arms are parallel to the ground.

When making the adjustment, remember to loosen (and re-tighten afterwards) the locking set screw. Adding a little anti-seize compound before turning down the spring adjuster doesn't hurt either.