Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
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HOMESERVICE MANUALSGMC1966PB25 SERIES 4.8L ENGREPAIR AND DIAGNOSIS (SINGLE PAGE)STEERINGMANUAL STEERINGMANUAL STEERING GEARS - (SAGINAW) RECIRCULATING BALLOVERHAULREASSEMBLY1965-74 ALL MODELS
1966 GMC PB25 Series 4.8L Eng
1965-74 All Models
1966 GMC PB25 Series 4.8L EngSECTION 1965-74 All Models
- Place gear housing in a vise with worm shaft bore horizontal and side cover opening up. With sector shaft and worm shaft seals, sector shaft bushings and worm shaft bearing races installed, and ball nut assembly together, proceed as follows: With "G" Vans, see step 2). Slip upper ball bearing over worm shaft and insert worm and nut assembly into housing feeding end of shaft through upper ball bearing race and seal. Place ball bearing in adjuster race and press stamped retainer into place with suitable socket. Install adjuster and lock nut into housing carefully guiding worm shaft into bearing until nearly all end play is removed from worm shaft.
- With "G" Vans, place worm shaft bearing in housing race. Slide other bearing and adjuster plug assembly over upper end of worm shaft. Insert worm shaft, nut and adjuster assembly into housing guiding lower end of worm into housing bearing. Thread adjuster into housing until nearly all end play is removed from worm shaft.
- With all models, position lash adjuster (with shim) in slotted end of sector shaft. Check end clearance which should not be more than 0.002" (see Fig 1). If clearance is greater than 0.002", a steering gear lash adjuster shim kit is available. Kit contains shims 0.063", 0.065", 0.067" and 0.069" thick. Lubricate gear with 11 ozs. of suitable steering gear lubricant (GM 4673M) as follows: Rotate worm until ball nut is at end of travel, place as much lubricant into housing as possible without losing it out sector shaft opening. Rotate worm until ball is at other end and apply more lubricant.
- Rotate worm until ball nut is in center of worm, this will help sector and ball nut engage properly. Insert sector shaft and lash adjuster screw (without side cover) into housing so center tooth of sector enters center tooth space in ball nut. Apply remaining portion of lubricant into housing. Install side cover gasket. Install side cover over sector shaft by reaching through cover with a screwdriver and turning lash adjuster screw counterclockwise until screw bottoms; then back screw off one-half turn. Loosely install a new lock nut onto adjuster screw. Install and tighten side cover bolts to specification.NOTE: If new side cover bolts are used, they must be specified bolts which are self-locking.
Adjust worm bearing preload and over-center preload as previously outlined in Adjustments.
TIGHTENING SPECIFICATIONS
| Application | Ft.Lbs. | ||
|---|---|---|---|
| Worm Bearing Lock Nut | |||
| 1965-74 All Models | 85 | ||
| Sector Lash Lock Nut | |||
| 1965-72 All Models (Exc. 1971 "G") | 30 | ||
| 1971 G 10-30 | 23 | ||
| 1973-74 All Models | 35 | ||
| Gear-To-Frame Bolts | |||
| 1966 All Models | 100 | ||
| 1967-68 Models | |||
| G & K 10-20 | 100 | ||
| P 20-30 (Horizontal Bolts) | 100 | ||
| P 20-30 (Vertical Bolts) | 50 | ||
| All Other Models | 65 | ||
| 1969 Models | |||
| G 10-20 | 100 | ||
| All Other Models | 65 | ||
| 1970 All Models | 65 | ||
| 1971-74 Models | |||
| G 10-30 | 110 | ||
| All Other Models | 65 | ||
| Pitman Arm-To-Pitman Shaft Nut | |||
| 1966 All Models | 95 | ||
| 1967-68 Models | |||
| G 10-20 | 95 | ||
| C 10-30, P-10 | 140 | ||
| P 20-30 | 115 | ||
| K 10-20 | 125 | ||
| 1969-71 Models | |||
| G 10-20 | 95 | ||
| C & P 10-30 | 125 | ||
| K 10-20 | 90 | ||
| 1972-74 Models | |||
| C, G & P 10-30 | 140 | ||
| K 10-20 | 90 | ||
| Side Cover-To-Housing | 25-40 | ||
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.