LEMON Manuals
: Even more car manuals for everyone: 1960-2025
Home
>>
GMC
>>
1993
>>
Forward Control 7.4 N
>>
Repair and Diagnosis
>>
Engine Performance
>>
Engine Controls - Specifications
>>
Quick-Service
>>
Service Intervals & Specifications
April 5, 2026:
LEMON Manuals is launched!
Read the announcement.
Service Intervals & Specifications
REPLACEMENT INTERVALS
Component
Interval (Miles)
Air Filter
30,000
Coolant
30,000
Fuel Filter
(1)
60,000
Oil & Filter
(2)
(3)
7500
Spark Plugs
30,000
(1)
On diesel engines, replace every 30,000 miles.
(2)
On diesel engines, replace every 5000 miles.
(3)
On turbo models, replace every 3000 miles.