1998 GMC 1500 Regular Cab Bolt Pattern
Checking fitment for your vehicle? Below you will find the factory bolt pattern (also known as the lug pattern) for the 1998 GMC 1500 Regular Cab, along with offset and center bore data.
| Bolt Pattern (Lug Pattern) | 6x139.7 (6x5.5") |
|---|---|
| Lug Nut / Bolt Size | 14x1.5 |
| Center Bore (CB) | 78.1 mm |
| Offset (ET) | 20-30 |
| Torque Specs | 100 ft-lbs (135 Nm) |
Imperial Match: 6x139.7 is commonly referred to as 6x5.5" in US Standard.
1998 1500 Regular Cab — Year-Specific Fitment Context
The 1998 model year is the final year of the GMC 1500 Regular Cab's 6x139.7 bolt pattern run (since 1992). Wheels from any 1992–1998 GMC 1500 Regular Cab are cross-compatible with the 1998 model.
GMC 1500 Regular Cab Bolt Pattern by Year
The table below shows how the 1500 Regular Cab's wheel specifications have changed over the years. The 1998 model year is highlighted.
6x139.7 Pattern Context
This bolt pattern appears on 1067 vehicles in our current database and is considered common.
Examples of other vehicles using 6x139.7:
Expert Buying Guide for 1998 GMC 1500 Regular Cab
For your 1998 GMC 1500 Regular Cab, the 6x139.7 bolt pattern is shared with 1992-1998 models. The 78.1mm center bore is critical; aftermarket wheels often have a larger bore, requiring hub-centric rings to prevent vibration and ensure load is on the hub, not the lug nuts. Offset must stay within 20-30mm; deviations risk rubbing on suspension or fenders. Always use 14x1.5 lug nuts with the correct seat type—factory wheels use a conical (60-degree) seat, while aftermarket may require ball or conical. Never mix seat types; improper seating can cause wheel loss. Re-torque after 50-100 miles.
Historical Fitment Data Reference
In our dataset, GMC 1500 Regular Cab appears from 1992 to 1998 (7 model years). Across recorded model years, this model generally keeps the same bolt pattern.
- Observed bolt-pattern variants for this model: 1
- Observed center-bore variants for this model: 1
- Observed lug-size variants for this model: 1
- Observed total offset span across years: 50.0 mm
Quick Tips & Safety Warnings
- ✅ Re-torque lug nuts to 140 ft-lbs after 50-100 miles of driving.
- ✅ If using aftermarket wheels, verify hub-centric ring inner diameter matches 78.1mm; otherwise, vibrations may occur.
- ✅ Avoid wheels with offset below 20mm; they may contact brake calipers or suspension components on this model.
- ⚠️ This fitment uses a wide offset range. Check brake clearance and fender clearance before buying wheels.
- ⚠️ Torque lugs in a star pattern to 100 ft-lbs (135 Nm), then re-check torque after 50-100 km (30-60 miles).
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1998 GMC 1500 Regular Cab — Frequently Asked Questions
What is the bolt pattern for a 1998 GMC 1500 Regular Cab?
The 1998 GMC 1500 Regular Cab uses a 6x139.7 bolt pattern (also called lug pattern or PCD). The center bore is 78.1mm and the offset is 20-30mm.
What other years of GMC 1500 Regular Cab have the same bolt pattern as the 1998?
The GMC 1500 Regular Cab uses the 6x139.7 pattern from 1992 through 1998. Wheels from any of these model years are dimensionally compatible with the 1998, provided the offset and center bore also match.
Can I put aftermarket wheels on my 1998 GMC 1500 Regular Cab?
Absolutely. Just ensure the aftermarket wheels have a 6x139.7 bolt pattern, an offset near 20-30mm, and a center bore of at least 78.1mm (using hub rings if larger).
How tight should I torque the lug nuts on a 1998 GMC 1500 Regular Cab?
Refer to your owner's manual for exact specs, but always tighten the 14x1.5 hardware in a star or crisscross pattern. Re-torque after the first 50 miles of driving.
What is the factory wheel offset for a 1998 GMC 1500 Regular Cab?
The OEM offset for the 1998 1500 Regular Cab is typically around 20-30mm. Depending on wheel width, a deviation of ±5mm is usually acceptable, but verify suspension clearance.
Will wheels from another GMC fit my 1998 1500 Regular Cab?
Only if they share the exact same 6x139.7 bolt pattern, a compatible offset, and a center bore equal to or larger than 78.1mm.
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