1997 GMC Suburban Owner's Manual - Page 302

Refer to the Maintenance Schedule to determinewhen to replace the air filter. See "Owner Checks and Services'' in the Index. Automatic Transmission Fluid When to Check and Change A good time to check your automatic transmission fluid level is when the engine oil is changed. off Operating the engine with the air cleaner can cause you or others to be burned. The air cleaner not only cleans the air, it stops flame engine if the backfires. If it isn't there, and the engine backfires, you could be burned.Don't drive with with it off, and be careful working on the engine the air cleaner off. Change both the fluid and filter every 50,000 miles (83 000 km) if the vehicle is mainly driven under one or more of these conditions: 0 In heavy city traffic where the outside temperature regularly reaches 90°F (32"C) or higher. In hilly or mountainous terrain. When doing frequent trailer towing. Uses such as found in taxi, police or delivery service. NOTICE: How to Check If the air cleaner off, a backfire can causea is Because this operation can be a little difficult, you damaging engine fire. And, dirt can easily get may choose to have this done at your GM dealership into your engine, which damage it. Always will have the air cleaner in place when you're driving. Service Department. i If you do not use your vehicle under any of these conditions, the fluid and filter do not require changing. See "Scheduled Maintenance Services'' in the Index. 6-20