The auto trans will downshift automatically when going up hill. Very seldom have I manually down shifted with an automatic going up hill, but I do down shift going down hill as a breaking method. Your trucks computer shifts the auto trans as needed. If your truck has an OD, it dosent go into OD until you are 40-45 miles per hr. Always drive in D unless you are pulling a load and need 3 to keep your rpm's up so the engine does not lug (strain). That should not be necessary with an auto if your tranny is in proper working order.
Finally some proper transmission advice. Those Chevys shift off of RPM and throttle. Itll shift just fine on it’s own. DONT drive around in 3rd gear ♂. Down shifting coming off the freeway or something is a good idea but don’t leave it in third. It’s just going to be bogged down.
Thanks I start learning this, I was used to manual gears all my driving life, this is my first automatic !
I’m not sure where to start here. There’s a lot of very knowledgeable, experienced people on here that’s giving you advice that has worked for them but isn’t great for your vehicle.
A. Don’t change you wheels and tires until you do a lift.
• Stock wheels won’t fit on lifted Chevys. The offset is way too high.
• 16” is no different than 17” when is comes to ride. 16” is getting harder to find, especially if you need a used one. 17” has been the norm across the board for over a decade. Almost 2 decades by now.
B. 245 to 285 is not 4 sizes. And definitely not 4”.
• 245, then 265, then 285. Half a handful of manufacturers make a 275 (BFG is one. That’s how you can tell who’s brand loyal )
• 245’s are around a 31 1/2” OD (overall diameter). A 285 is just under a 33”
• The first number is the aspect ratio (tread face). 285mm. The second is the section height (sidewall) 75% of 285mm. The last is the wheel size. A 285/75-16 is the same as a 285/70-17. See? Rim size goes up, section height goes down, overall diameter stays the same.
C. The more you adjust the torsion bars, the stiffer you’re ride will be. Use the adjustment to dial your ride, just don’t crank them up for your sole means of lift. It also puts your front drive axles at a more extreme angle increasing wear.
D. The lift kits for IFS suspension on those models are permanent. No big deal but the “in case you go back to stock” comments are from guys that have never had one. The 6” is usually cheaper than the 4” because of popularity. 4” is a waste of time with the Chevys anyway. Fender trimming and mild torsion tweaking will get you a 285. A 4” that’ll run you over $1k will get you...a 285. Don’t bother. When Chevy got away from IFS and switched to struts was the best thing they did. $300 puck kit would get you a nice, fat tire.
E. Unless you’re rock crawling or towing a ton, you don’t need to re-gear. I’ve put over 100k on my lifted truck (35’s) with Stock gears. Re gearing is not a bad idea, but a lot of money that could be put elsewhere on a build.
Ultimately, do what you want. But, for right now, I’d get a good set of 3peak tires for this trip. When you get back and start your build, sell them. Used 16” snow tires in Canada will sell by the end of the day. Put that money into your wheel/tire/lift bill. Yes, all 3 of those need to be done at the same time on an older Chevy so start saving. Hope I didn’t bore you to death.
