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Hey need help. My son total out a 2009 GMC with a 6.2 and 6l80e trans. I have the truck and all. Looking to put it in a 1997 GMC truck. I am trying to figure out how to get the trans. to work and know what gear I'm in. Do they make harnesses for this or control modules for this. Thanks for any help.

2017 1500 SLT, 52kmiles, stock other than GM/Borla. Truck is never used for towing, but is my daily driver. I noticed recently there is an "odd" upshift between 2nd and 3rd at random times. Usually after driving for a while. Took it in to the dealer who says all is good, no burned fluid and can't duplicate the issue--they say they took it up to ~190. I drove the truck about 470 miles this weekend on vacation after dealer cleared it, but monitored the tranny temps more closely and noticed on the long highway drive with minimal cargo/passengers temp is sitting around 225-232. Ambient temps in the upper 90's. This seems high to me with very little load, but I never really paid attention to temps prior to the shifting issue... so no baseline to compare to. What temps are expected/normal?

I have a 2019 Silverado LD with 21k miles on it. I noticed that if I'm in manual mode, I get a hard downshift from 3-2. No other gears. It does it off and on. What could it be?

Okay, after 11 months of agonizing mishaps, set backs and over all triumph, I figured it was time to immortalize my truck in a new post. Please welcome my 2014 GMC Sierra 1500 7.0 (427) Turbo Build! Block: Texas Speed and Performance Darton sleeved boost ready block; 7.0L (427). TSP Forged wet sump crankshaft 4.0" stroke 6.125 Boost specific billet I-Beam Rods CP 4.125 -12cc Dish Pistons w/upgraded wrist pins. Clevite main bearings Clevite rod bearings ARP Main stud kit Cylinder Heads/ Intake Precision Race Components ported Cylinder Heads w/ valve job PAC spring/ Valve Kit. Comp Cams rocker arms/trunion Texas Speed & Performance SV Camshaft +30% fuel lobe TSP AFM delete kit Lingenfelter ported 95mm throttle body Ported L86 intake manifold. All ARP bolts or studs. Fuel: GM ZR1 high volume fuel injectors GM ZR1 fuel pump (high side) Armageddon 465 LPH in tank fuel pump (low side) Snow Performance Stage 3 Meth Kit with controller and braided lines. Turbo: Borg Warner S480 T6 Turbo 1.32 AR billet 110/96mm. Turbo smart 50mm BOV Turbo Smart 60mm waste gate Pro Boost controller fully titanium wrapped exhaust Cooling/Oil separators Mishimoto fully aluminum Radiator Mishimoto R-Line Intercooler 31x 12x 4” Mishimoto HD Trans Cooler 2X Mishimoto Black Aluminum catch cans. Mishimoto 180 degree thermostat. Transmission/driveline: Circle D pro 3 torque converter 2700 stall. Custom 5" 6061 aluminum driveshaft rated for 1,200hp 7,300trq MORE to come. I need to get the final tune with the new block. Still runs very well on the old 6.2 tune however, going up to 7.0 adds a layer of goofy on vacuum or under boost.. Next steps Get the PATC Stage 4 transmission kit stuffed into my 6L80E and retune to 900+ whp! Hoping to have that underway around March! Let me know what you all think. Ask any question. I'm open to where I purchased parts, cost of build etc. especially my opinion getting into a build like this.

Hey guys, new to the forum. I have a 2016 Silverado 1500 with the dreaded whine that seems to be the torque converter. I am almost certain that is what it is. The only video I’ve found that has the same exact sound is here How hard is it to pull the transmission just to swap out a nee TC? Does that sound like the TC or the pump? Anything I need to be sure I do? Truck is still driving fine, but not sure for how long. Any tips would be appreciated. Also looking for the best TC that will last.

I had purchased AMSOIL Signature Series ATF for my 18 Silverado - 6 speed. After having it sit for a while and never getting to a transmission flush on my own time, I called a local, honest, reputable transmission shop near me that has always treated my dad very well. They’re a no-bull, honest shop, and the owner is down to earth and knowledgeable regarding transmissions, as he should be. I informed him I had AMSOIL and wanted it switched with that, and he advised that for the 6L80E, it wasn’t a great idea. He has nothing against a better fluid, but he advised that AMSOIL doesn’t treat the electronics nicely, and it’s a common issue. I’m an AMSOIL guy, and do want him to use the AMSOIL fluid, but has anyone else heard of this or advise to simply use DEXRON VI and NOT AMSOIL?

So I've been dealing with this clunk on my '14 6.2 Sierra crew s/b. It is most noticeable when letting of the gas in second gear, but is also noticeable in higher gears to a lesser degree. It will clunk every time I let off the gas in second gear. The driveline will absolutely not clunk in first gear. The first time I took it in to the dealer the service manager rode with me and agreed that the clunk didn't seem normal and suspected the rear axle or driveshaft was the culprit. I was pleased that he appeared willing to dig into the problem and was hopeful for a resolution. Later that day I returned to pick up the truck and was told that they performed the TSB relating to torqueing the shackles and U bolts. I didn't expect that to fix the problem and it certainly didn't. I brought the truck back shortly after and they checked for any TCM updates to no avail and opened a case number with GM. After that they handed me the TSB stating that clunking is normal. Yesterday I went in for an oil change and told them I'm still not satisfied with the low speed clunky driveline of this truck and asked to drive one of their loaners to compare the low speed driving characteristics. The truck I drove had no noticeable clunking at all. This test drive only reinforced my belief that something in not right with mine. Of the 5 late model full size GM 4x4 vehicles I've owned none of them clunked like this 2014. An occasional clunk is to be expected especially in a 4WD and I could live with that, but this thing clunks all the time! This does not seem appropriate for what is otherwise a very nice driving and expensive vehicle. I am totally frustrated with how my dealer and or GM is handling this case. Has anyone had any luck getting this type of issue fixed? Any insight is appreciated.

Just wanted to post on here, as I have seen no less than a thousand posts with questions about the 6L80E, specifically about the power threshold of a stock unit. I have a 2014 GMC Sierra SLT Crew Cab Standard Bed stock 3.42 gears stock drive shaft stock 20" rims/tires 6.2L fully forged top/bottom end "Armageddon Twin Nagasaki's" (GT3582R's) e-boost 2 gauge Z06/LT4 fuel system 365lph in-tank Armageddon fuel pump QTP exhaust cut-outs and laid down 965rwhp/850 rwtq on a mustang dyno with 18psi on 116 race fuel (cut-outs open). I say all of this because the stock transmission detonated the 4-5-6 shaft (intermediate hub) near the splines. I took it to a "race shop" that said they would upgrade as much as they could; and was told at the time, there were limited aftermarket parts available for the 6L80E. This was mid 2018 with less than 10K miles on the truck and about 500 miles on the engine/turbo build and I discovered that was not entirely true. I drove the truck after their work, with "spirited road driving" while the roads were wet no less. Long story short; they f'd me and I detonated the 4-5-6 stock intermediate shaft again within 100 miles and no traction at all. They apparently replaced all parts that were broken with stock parts! Moving on, I took my truck to a different shop and researched my a** off and found PATC Transmissions. I had a warm and fuzzy after speaking with them and ordered the Phoenix Level 4 Master Rebuild kit among a few other minor accoutrements and re-tuning of my TCM by Mike from Century Automotive. It is now APR 2019 and I am about 1 1/2 weeks away from having the my billet planetary gear mailed to me; for the new, more reputable shop in my area to install all of this PATC bada**ery. If anyone is truly interested, I will post new info once I put the new Phoenix Master Rebuild kit through the ringer with the full weight/horsepower/torque of my particular application...I hope this helps if there are some lost souls out there that may be headed down the same long. hard. road. of a "full send" like myself! Please post if you have questions/comments/concerns; as I have "been there done that and forgot the t-shirt" with the L86/6L80E so far.

Hi Long time lurker , i have a 2017 Gmc Sierra 1500 with the 5.3with the 6l80e . Im a trying to add a auxiliary transmission filter. i wanted to go with the the derale part number 13005 in conjunction with a NAPA 1269 filter. i have read both write ups done by FL335i and cossack. But on my truck the lines are routed different i included the attachment below .I want to try use an AN Adapter fitting to replace the #2 which is the gm quick disconnect19210848 with something like Earl's Performance AN to Straight Cut O-Ring Fittings AT949094ERL. but im having trouble coming up with a solution for how to adapt the AN line to the hard line. i know the AN line is probably over kill but i want to install it and not have to worry about it leaking or blowing out because i drive alot for work. if anyone can give me an input on this and any ideas or part numbers that will be appreciated. -Alfredo Excuse my chicken scratch but i figured it would help explain my ordeal a little better.

Hi, first time posting on here, I hope I am not bringing up an issue that has been solved or brought up elsewhere. Here we go, I have a 2015 single cab swb 4x4 that came with a 4.3/6l80e, i have swapped this to a 2017 l86/ 8l90e. Truck was fully operational prior to swap no issues, upon completing the mechanical portion of the swap and starting the electrical checkout I have run into some issues. Truck will power up bcm/ gauge cluster with no issue/ lights but I have no ecm activation as fars fuel system coming on or engine rolling over. I am getting the following DTCs: 2535, U0100, 1029( low voltage from fuel system). I have reached out to 8+ different shops for assitance and offered to pay for their time but have not recieved a solution or either not enough experience with newer truck/ motor systems, if there is anyone that has any thoughts/ recommendations/ experience/ solutions on this would be great or a capable shop around north Texas, I am all ears, really excited to figure out what is going and get this on the road. Also everything is 100% factory parts other than texas speed cam and delete kit.

Hey Folks, I've been searching all over the NET for info on this situation. I have a 2014 Sierra 1500 Denali 4x4 equipped with a 6.2L and the 6L80e. I'm looking to swap in the 8l90 and would like to know what it will take. The engine set up is capable of producing over 1100 hp however, I'm restricted due to the transmission. Any assistance would be appreciated.