Hello! just wondering what mods or any would void the warranty on the transmission. I have a 2008 Trailblazer SS with 24K miles on it. It has the standard factory warranty plus the extended warranty. I was looking to install a CAI and then get a tune done by PCMforless and was wondering what warranty's those updates would void. Any info would be great. I've read a lot of "opinions" online, but looking for facts without calling the dealer. Thanks! Chuck

SOURCE: Hello! just wondering what mods or

Most warranties will be considered void if you do any suspension mods, use larger than factory approved tires, use the vehicle off-road, in competition or commercially.
Personally, I don't see much benefit in cold air intake systems as the engine controls are calibrated to maintain a specific fuel mixture and may just alter the fuel flow to "compensate" for what you did.
If it is beyond the systems ability to compensate, you may get incorrect O2 sensor readings. In order to benefit from that, you'd need to change the camshaft and add headers (you can't put in what you can't get back out) and alter the exhaust system. (those items may void the warranty)
Altering the factory advance and fuel curve may have some benefit but if you read carefully, most ecm mods show power gains in a part of the rpm range that you don't ordinarily use (from 4500 to 6000rpm).
Here's an opinion: For the amount of work you'd need to do to gain even 20 hp, risking having the warranty not cover anything (once voided nothing is covered) It's not worth doing 'till the warranty has expired. As an inspector, I've seen many claims denied that personally I would have approved but if the contract says a certain change makes it void, it's void.
Based on what I just said, and the fact that I was a warranty inspector for about ten years, but left the business before those mods were common, I'd expect that the warranty companies may have added restrictions in those areas. Everything you need to know is written in the paperwork they give you...never base anything upon what you were told. What's written in the contract is binding on you and the company.
If you do decide to make any alterations, try to not make it super obvious. Save your factory air system and put it back on if having warranty work done and don't show up at the dealer with the engine bay full of mud, a ton of construction equipment in the back or anything else that would be super obvious that you have done any mods.