Tire Rounding - A smoother ride for your vintage truck by Dave Langford, featuring his Dodgebolt Power Wagon
Now that you've done a drivetrain upgrade to your Stovebolt, you love that smoother power and comfortable highway cruising. But that handling ... That ole straight axle up front was great for the roads of the Great Depression but it leaves a lot to be desired when tackling modern highways. Time to retire it! Cut down on all that wander, bring some order to the chaos with an Independent Front Suspension!.
Independent Front Suspension
By John "johntsmith" Smith Bolter # 26358 1965 Chevy 1/2-Ton 1953 Chevy 5-Window 1/2-Ton 1966 Chevy 3/4-Ton
1959 Chevy 3200 Longbed
1953 Willys Overland Pickup
1966 Dodge A100 Pickup
Upgrading your ride to a modern Independent Front Suspension isn't some high-level upgrade for TV shows and high end shops. While not an entry-level / beginner project, with a few tools, a lot of patience and methodical work, medium to advanced wrench benders can fit an IFS kit to a truck in their own garage or shop. Follow along as we demonstrate what's involved -- maybe you'll find this is a project you'd like to try.
3 foot pry bar
Hand sledge hammer
To make this upgrade for my 1941 Chevy 1/2-ton, I ordered the Total Cost Involved IFS kit from Classic Performance Products. There is a kit that covers 1941-46. Another kit covers 1938-41 which is slightly different. The kit which covers 1947 and above is very different. However, the principal for the IFS Swap outlined in this Tech Tip are pretty much the same.
5. Using square and digital level, scribe center line of front axle on both sides of the frame.
6. Remove front axle and springs.
7. Grind rivets out of frame and remove shackle brackets. The sledge hammer and chisel will help.
1. Remove the front clip; remove the fenders.
3. Remove the cab (optional).
9. Using your square, mark and cut the bottom of the frame even with the top of the frame.
10. Weld a plate onto each side of the frame, channeling it. Only weld small sections at a time so as not to overheat the frame.
12. Slide the radiator support back into the frame, but do not bolt in place.
13. Clamp the new center support in place. Center of the center support is centered on the scribed marks on the frame. If you forgot to scribe the center line of the front axle, measure 16 11/16 inches from the center of the furthest front hole on side of the frame. Check frame to support draft and adjust to 2 degrees.
14. Spot weld the center support and double check the draft angle.
8. Grind rivets out of radiator bracket and remove – retain for later use.
11. Grind the welds smooth.
16. Bolt radiator support back in place. You may have to pry it a little to get in square.
17. Measure 5 1/8 inches forward of the axle center line and scribe a vertical line.
18. Measure up 1 3/4 inches from the bottom of the frame and mark.
19. Mark a 3 1/2 inch semicircle centered on that point.
20. Cut the semicircle out. I drilled a series of small holes around the inner of the circle. Then using the small holes as leads, drilled larger holes. Then used a small Dremel cutting wheel to remove the small metal bridge between the holes; making sure this was smaller than the area that needed to be removed so I could do follow up grinding later.
15. Finish welding the center support in place.
21. Next using the square mark, cut the bottom of the frame even with the outer edge of the semicircle.
22. Mark a semicircle on the inside of the frame and cut out.
23. Cut a 3.5" pipe the width of the frame rail and cut in half.
21. Grind frame rail to match the half pipe.
22. Weld in place.
23. Grind the welds smooth.
24. Using the rack as a guide, mark and trim the radiator support so rack will have more than one-half inch clearance behind it.
25. Install lower control arms.
26. Install the shock in the lower control arm. Measure and center the upper spring tower to center of axle line. Towers must be parallel and at 27” apart +/- 1/16”. Make sure towers are vertical at +/- 0.5 degrees. Tack weld in place. Shock should line up perfectly. Remove shock and finish welding.
28. Clean and prime / paint area.
27. Mount rack. Bolt engine mounts to engine and lower engine into frame and tack weld mounts to cross member. Remove engine and rack and weld engine mounts in place.
29. Mount engine and transmission into frame.
30. Using a spring / strut compressor, compress the spring. Install spring with the flat side up and pig tail down. Jack lower control arm up to hold spring in place (if lower ball joint has a grease fitting, remove before placing jack under it) by jacking under lower ball joint until weight is taken off the jack stand. Install the shock. If the shock does not fit all the way through the upper shock tower, tighten the compressor more.
31. Bolt on upper control arm.
32. Bolt spindle / rotor to bottom ball joint.
33. Bolt spindle / rotor to upper ball joint.
34. Center the rack. Turn steering shaft completely in one direction. Measure distance rod end protrudes from rack (measurement A). Turn steering shaft completely in other direction. Measure distance rod end protrudes from rack (measurement B). Subtract these two measures and then divide by 2 [(A-B)/2 =C]. Add this to the smaller dimension (B+C=D). Turn steering shaft until rod end protrudes to D measurement.
35. Bolt rack into place
36. Align the 2 rotors so they are parallel to each other. Clamp one piece of angle to the each rotor. Bolt one piece of exactly same sized angle to each end of one of the angles clamped to the rotor. Loosely clamp the angles to the other angle clamped to opposite rotor. Measure the distance of each angle protruding past the clamped angle. Move rotor until both protruding measurements are the same. Tighten clamps. Double check measurements. Angles should now be square to each other. This will get the alignment almost correct (most times it doesn’t need further adjustment)
37. Screw on tie rod end until it slides into spindle without the spindle moving. Add the nut and tighten. Add pin. Double check measurements to make sure nothing moved. Install other tie rod end the same way. Double check measurements again.
38.Level center support. Using the digital level, adjust the camber on each wheel by adding or subtracting shims between the upper control arm and the spring / shock tower. Adjust to manufacturer’s spec. (TCI’s is zero degree)
39. If using a power rack, connect the hydraulic lines to the rack.
40. Connect lines to pump and mount pump.
41. Connect sway bar to cross member and lower control arms.
"When we tug a single thing in nature we find it attached to the rest of the world." ~ John Muir
"When we tug a single thing on an old truck, we find it falls off." ~ Bill "red58" LePage