when to change fluids

04silverado1500 · January 6, 2007

hey i was just wondering how many miles i should change my trans fluid and diff. fluid and how i should do that. i have heard from people that you should change the filter and from others that its bad. also i need a mileage increment that it would be good to do this at. i am aproaching 50 k soon and want to stay on top of things ill be replacing tires and possibly the fuel filter at the same time (if i need to). in addition i thought about doing a coolant fluid change. if there are any other things i should look into let me know i have changed the airfilters done routine oil changes every 3k weather it needs it or not and i have rotated tires. opinions please!

just thought of another thing i was planning on running through two pints of seafoam through my gas tank just to give it a good cleaning is that a good brand. i have also thought about switching to syn.\thetic oil but my neighbors 03 navigator started leaking oil once they switched over so im not sure what i want to do. im also in the every 3,000 mile oil change club good or bad it cant hurt my truck so i do it especially with almost all of my driving being city it puts alot more stress on the truck

99silveradoz71 · January 7, 2007

50k isn't a bad place to start with the fluid changes depending on your usage.

04silverado1500 · January 8, 2007

tows a 2k lbs boat regularly in the summer nothing big and used to be used to haul to small diesel john deere lawnmowers. it hasnt towed to much as of late but quite often early on in its life. i also drive all city almost.

C & A s Dad · January 9, 2007

Change the Trans fluid and FILTER. Switch to syn trans fluid if you like and especially if you plan on doing any more towing than you are currently doing. Amsoil's website contains good info on doing this to replace all the fluid. I would suggest doing this every 30K.

At 50K, I would change the gear oil also. Be sure you use the type of syn gear oil that is recommended in your owner's manual. This is critical for proper performance.

Many people switch to Syn oil at the miles you have and never have had an issue. I did it in my current YUKON XL at 40 K with no issues.

Coolant, IMO, you need to flush and fill now and do not try to wait until the 5 yr period as recommended in your Owner's Manual. I would recommend replacing with Dexcool, which is what came in your truck. I also use and recommend a product called Kool It by Lubegard. It is an excellent product that will eliminate all Chemical Electrolysis.

Seafoam is a great product and we sell an ocean of it every month. However, I like Chevron's Techron better. It will run you about $10.00 for a 20 oz bottle. Run it at 1 oz per gallon and if you really are concerned that your comb chambers and injectors need it, run the Techron for 2 tanks back to back. It is a wonderful product and it really works.