Sergio Mendez

I won't be doing the install, my trusted mechanic friend will but I want to research and supply the parts instead of having him choose. I know sonnax has a lot of parts I'm just not sure what to look for. I'll take a look at the videos you sent and will send also to my friend to take a look. Thanks! Hi, care to elaborate? How is that done? Or do you had a full new transmission installed? Is there a kit to rebuild and convert? Sorry I'm new to transmission.

Hi guys, Wondering what I have to do to upgrade the stock transmission for my 2007 new body style. Not sure where to start. Car is around 325k miles and engine was rebuilt 20k miles ago. Transmission is working fine but has never been rebuilt. I'm using the truck now to tow my Toyhauler. I'm afraid that one day towing the transmission might blow up or leave me stranded while towing. From what I understand, rebuilding trans with a HD kit should help alleviate some of the extra strain when towing. Care to guide me in a better direction? Happy to answer questions.

It was rebuilt at around 120K miles... Not sure how much power can be squeezed from a 5.3 Toyhauler has a GVWR of 7500 lbs. Im estimating that with ATVs and toys loaded, I'll be around 8500lbs . That would be over the recommended towing for the 5.3 by quite a bit, and borderline for the 6.0 I know the ideal thing would be to just buy a bigger truck, but with current prices and inventory, thats not an option.

Thank you! I see a LY6 available near me, might go take a look. Will do some more research from people that did a similar swap.

Hi, new to the forums! My dad has owned a sierra 2007 for a long time now. It currently is around 350k miles with a rebuilt 5.3L around 120k miles. Transmission has never been rebuilt nor repaired. Car has been well maintained overall, but the engine feels weak and tired now. I'm in need of a towing truck for my toy hauler, and have been toying with the idea of swapping the 5.3 for a 6.0 LQ9 from a 2003 Chevy 1500, since all new/used trucks are crazy expensive due to the pandemic. A jump to the 6.0 would also give me some increased towing power also. I found an LQ4 with 130k miles, pulled from a sierra 2003 1500. It comes with 480L tranny, ECU and harness. I feel like this should be a direct swap, but is there anything else I should know? Would this still be a reliable car after an engine swap? Don't want to be left stranded on the road with a 21' toy hauler In Baja .

Hi, New to the forum and to towing, so sorry if my questions are kinda dumb. I have a 2007 GMC Sierra with over 300k miles, it has been a dream to drive and recently got a new engine, so there should still be plenty of miles left on it. I just bought a Toy Hauler (Max Weight should not tops 7000lbs), and wondering what kind of upgrades I Should be looking into for efficient and safe towing. Keep in mind the truck wont be used as a Daily Driver for much longer, so Efficient towing is the priority. The truck is equipped with the HD Trailering Package, Z71 Offroad suspension and 3.70 rear gears(Already pulled the Build Sheet). My toy hauler also came with Sway Bars and Weight Distribution, and I bought a Weight Distribution Hitch and Brake controller. Pretty sure all of the shocks need replacement. My questions are, What shocks should be good for towing with this truck? Should I add an extra Leaf to the rear? Airbags? I read somewhere that the transmission cooler should be upgraded since the one that came with the truck is not that great. Any engine performance mods that I should look into to help towing? Any Input helps, and Thanks for taking the time to read my post!