Hurst Shifter Guide

Overview

This guide covers disassembly, inspection, cleaning, and reassembly of classic manual transmission shifters, focusing on the Sparkomatic, Hurst Competition Plus, and other period shifters. It also explores a few unique designs from the 1950s and 60s, including early sequential mechanisms.

1. Sparkomatic MA500 Shifter (Mario Andretti Model)

• Era: 1950s
• Design: T-handle floor shifter for 3-speed column-shift conversions.
• Gates: Two—one for 1st & reverse, and another for 2nd & 3rd.
• Material: Die-cast aluminum/pot metal (fragile and prone to breaking).
• Purpose: Allowed conversion from column shift to floor shift for performance feel.
• Key Notes:
  • Simple two-gate mechanical design.
  • Built-in stops prevented over-travel and linkage damage.

2. Hurst Competition Plus Shifter

• Background:
  • Direct descendant of early Sparkomatic and Hurst 3-speed shifters.
  • Still in production and widely used in 4-speed transmissions.
• Common Issues:
  • Accumulation of dirt and grease.
  • Worn pins, plungers, or gate plates causing sloppy shifting.

3. Disassembly Process

Tools & Materials Needed:

• Threaded coupler (e.g., from Home Depot)
• Socket head screw
• Wrench and pliers
• Small screwdriver
• Mineral spirits or parts cleaner
• Pin punches
• Vise
• Steel wool and brushes

Steps:

1. Remove dust plate: Pry off gently using a screwdriver.
2. Extract pivot pin: Use custom spreader tool or pliers to separate base.
3. Disassemble arms: Lay out 1-2, 3-4, and reverse arms in order.
   • Reverse and 1-2 arms bend inward.
   • 3-4 arm bends outward.
4. Inspect holes: Ensure they are not oblong; inspect spring shims.
5. Remove plunger assembly: Carefully knock out pins; note sizes and alignment.
6. Clean all parts:
   • Soak in mineral spirits.
   • Use steel wool to remove rust or grime.
   • Avoid wire wheel unless necessary.
7. Inspect pivot pins and gates: Check for excessive wear.
8. Avoid full plunger disassembly unless necessary—it’s spring-loaded and difficult to reassemble.

4. Cleaning Tips

• Homemade cleaning setup: Use a metal pot and mineral spirits if no parts washer is available.
• Inspect during cleaning: Check for wear or oval-shaped holes.
• Use steel wool: Effective for removing minor rust and residue.
• Avoid aggressive abrasion: Preserve plating and surface finish.

5. Reassembly & Alignment

1. Reinstall plunger:
   • Align holes correctly (one side slightly larger).
   • Insert pins carefully with punches.
2. Apply light grease to moving parts.
3. Ensure correct gate bias:
   • Default bias is toward the 3-4 gate.
   • Pivoting action moves between 1-2 and 3-4 gates.
   • Additional effort required for reverse gate.
4. Replace dust plate and pivot pin.
5. Check movement: Smooth, no binding, no excess play.

6. Mounting & Adjustment

• Installation Kit Used: Hurst 373 3163
  • Fits Auto Gear and GM transmissions.
  • Same kit used for mid-50s Chevys.
• Hardware Tips:
  • Use Grade 8 flat washers (stronger than supplied ones).
  • Ensure hardened steel bushings are installed for rigidity.

7. Common Variants

• Alternate Hurst Bodies: Slight differences in arm bends or gate shapes.
• Rolltech Shifter:
  • Billet aluminum design.
  • Modeled after the Hurst Super Speedway shifter.
  • Uses identical internal gate and plunger mechanism.
• Maintenance Note: All function similarly, basic cleaning principles apply.

8. Rare & Oddball Shifters

Example: Beaver Changer (1960s)

• Claim to Fame: First sequential shifter for Muncie 4-speed.
• Operation:
  • Two handles—one for upshifts, one for downshifts.
  • Both pulled in the same direction for each action.
• Design: Rotary cam mechanism attached to transmission side cover.
• Issues:
  • Large and space-consuming.
  • Required floor modification.
  • Mechanically complex but innovative for its time.

9. Key Takeaways

• Always document part orientation during teardown.
• Avoid forcing corroded pins or bolts.
• Clean thoroughly but preserve original plating.
• Light lubrication on reassembly prevents corrosion and maintains smooth motion.
• All manual shifters, from Sparkomatic to Rolltech, share similar internal gate mechanisms.

10. Recommended Maintenance Products

11. Final Thoughts

Whether you’re restoring a 1950s Sparkomatic or maintaining a Hurst Competition Plus, proper disassembly, inspection, and reassembly will extend life and ensure crisp shifting. Each shifter tells a story of engineering evolution—from simple two-gate designs to complex sequential mechanisms—and all deserve preservation.