What did you do to your NNBS GMT900 Tahoe/Yukon Today?

[kbuskill]

Now you just messed everybody up lol!

I thought it was strange myself. I realized it when we replaced his ECU. It has the TAC (throttle actuated control) module mounted up on the firewall in the drivers side top corner.

I myself, having never owned a GMT800, have never done a ton of research on them but I always assumed they were all DBC.

 

[Just Fishing]

My buddies 2001 Suburban is a DBW.

I'm not sure of the build date though.

I don't know what to believe any more.

 

[kbuskill]

I don't know what to believe any more.

It is possible that his may have been one of the last 2001s built and got the DBW. Like I said, I was shocked when I realized it.

 

[Just Fishing]

Mmm pretty porting tools!

And my precious.
(box of 3m cross buffs in all sizes, grits, and even little ones that fit in the oil pump passage ways)

Got some in here that i used in a few choice locations in the block.


it should flow oil good yes yes.

 

[Rocket Man]

I thought it was strange myself. I realized it when we replaced his ECU. It has the TAC (throttle actuated control) module mounted up on the firewall in the drivers side top corner.

I myself, having never owned a GMT800, have never done a ton of research on them but I always assumed they were all DBC.

I found out when I went to buy a Whipple and Blackbear said it has to be a dbw truck or it won’t work. I was relieved. Whew! Almost saved a bunch of money. That would have sucked.

 

[08z71bgm]

Is this the box? If so it looks like it’s only for converting 58x to 24x, not the other way. 58x gear sounds like the way to go.

So far it seems like 58x reluctor, gen IV timing cover and 4x timing gear, relocate knock sensors, and use my factory gen IV harness and computer. That doesn’t seem too bad...

View attachment 280523

That’s it. Guess you’ll need to swap the reluctor to a 58x during the rebuild.

 

[gooffeyguy]

Learned some new abbreviations today! DBC and DBW

lol

My '01 is DBC

 

[Sam Harris]

I think it was only on the LQ4’s and LQ9’s. And some 02’s had dbw and some dbc. Just wanted to get it out there that dbw wasn’t just a gmt900- up feature.

Yup. My ‘03 Yukon is DBW

 

[FrankU]

Do all 6L80E transmissions have thermostats in them ?

I know my 2016 6L80E has a thermostat but I'm not sure about the 2011.

 

[08z71bgm]

Do all 6L80E transmissions have thermostats in them ?

I know my 2016 6L80E has a thermostat but I'm not sure about the 2011.

It should not be in them but before the cooler. Bypass. Should go into the radiator then to the bypass and back until it reaches temp. The cooler only works when it’s 180 and up. At least that’s how my car is with it. I don’t have a truck with it yet.


@iamdub so you did the 6l80 swap in a 4l80 nnbs?

 

[Doubeleive]

Do all 6L80E transmissions have thermostats in them ?

I know my 2016 6L80E has a thermostat but I'm not sure about the 2011.

no, not sure when they started using them I am going to guess 2015 though when they did the redesign, the thermostat is attached to the bottom/side of the transmission can't miss it, it's set to open at 180deg, I disabled mine on the 2018.

 

[RooTBeeRthe1st]

no, not sure when they started using them I am going to guess 2015 though when they did the redesign, the thermostat is attached to the bottom/side of the transmission can't miss it, it's set to open at 180deg, I disabled mine on the 2018.

I've never noticed one on my '14

 

[iamdub]

I love it, 120mph and a TPMS warning light. Too funny.

Ahh to be young again..

Had my 22s on back then. No sensors in those wheels. I do a lot of stupid things, but I'm not gonna ride on a low or flat tire!

 

[wsteele]

Had my 22s on back then. No sensors in those wheels. I do a lot of stupid things, but I'm not gonna ride on a low or flat tire!

I knew you knew exactly what you were riding on.

 

[iamdub]

Remember, the calibrations offered are VIN specific. I looked up two 2007 Tahoe VINs a very early and very late one and they were not exactly the same as far as ECM calibrations offered. GM made new calibrations for my truck even so I could install one of their GM accessories a while back.

I wish I knew more about the systems to figure a way to run a 2008+ program on a 2007.

Swap the PCM? What's the difference(s)?

 

[iamdub]

Here is a write up and list of parts from someone who used a gen 3 in a gen 4 truck.

These are my thoughts and my unprofessional opinion from what I’ve gathered so far... If someone just wants a really simple swap with a mostly stock engine that they do not want to tear into, then it makes zero sense to use the gen 3. However, if I already have plans of going through the engine completely, then it doesn’t seem like much more effort would be needed. An LY6 might be ideal, but I’m not yet convinced it’s worth the hassle of selling the LQ4 and finding/paying a bit more for an LY6.

thoughts?

https://www.performancetrucks.net/f...4l60-2007-nnbs-swap-2003-lq4-6-0-4l80-556285/

Been absent for a few days. Looks like you have it handled, though.

Yes- if you were planning on minimal work and dropping in the LQ4 as-is, then you'd have problems. Since you're taking it apart, it's no big deal. Get a 58x reluctor wheel or swap the one from your 5.3 if you're taking it apart. The wheel has to be pressed onto the crankshaft, which means the crankshaft will be removed from the block. Swap your 5.3 front cover to the LQ4 or get another for a Gen4. You can leave the Gen3 cam sensor in place or (preferably) remove it and plug off the hole to ensure no leaks. You can drill and tap the block for the Gen4 knock sensors, but be careful. The holes are blind and you do not wanna drill all the way through. Copy the Gen4 location and depth exactly. There are 4x cam gears to bolt to Gen3 cams (Gen3 has three bolts, Gen4 uses one large bolt), GM part no. 12586481. This is a common part since most aftermarket LS cams are made for the Gen3 three-bolt pattern. Also, IIRC, you might have to swap two wires around on the cam sensor. I think the circuits are "polarized" opposite between the two gens of engines. Swap your intake manifold onto the LQ4 and your factory harness will be plug-and-play.

 

[iamdub]

@iamdub so you did the 6l80 swap in a 4l80 nnbs?

I wish. I've looked into it enough to wanna do a T56 swap instead.

Best I can tell, the easiest way to convert to the 6L80E and have everything work like factory would be to get the entire setup from a parted-out '09+. You can get the 6L80 in there and running with just the trans, modified harness and tune, but you won't have TU/TD, manual control, nor the proper gauge cluster that displays the current gear.

For me, having manual control over those extra gears is one of the main points. I believe I "switched gears" in the research when I saw that the TU/TD control goes through the BCM. So, there'd be some reprogramming there, and even then, that may not work. IIRC, trans tune segments from a Corvette would need to be used. That's why I say you just swap everything (PCM, harnesses, BCM, gauges, shifter, etc. from a '09+ so your truck will essentially be an '09+ electronically and semi-mechanically.

Do a manual trans swap or get a newer vehicle if you really want the extra gears.

 

[iamdub]

Did nothing to it today other than watch it drive away. Jenn's back behind the wheel.

Yesterday, after filling the tank with ~$80 worth of Exxon 93, I took it and a tow dolly two hours away to Gretna (south of New Orleans) to bring home a parts car:

Yes, I'm (again) towing on my Jeep Wrangler "drop" coils and Airlift bags. I might could've used 1-2 PSI in the load bags to pick up the rear a hair. But, it sat level, rode fine and wasn't dangerously squishy at all. Not once did it feel uncontrolled. I'm still running the air that was in them when I picked up that golf cart from Tampa back in November. Haven't touched 'em since.


Had this ugly mug tailgating me for two hours. 81° ambient:

Yet again, I'm proud of this 'ol gal! Cruised at 65MPH, getting 19MPG. Taking her up to the speed limit of 70MPH cost me 1MPG and 1° higher trans temp:

Yes, that's the instant MPG. It bounced around 18-20 due to road conditions, but stayed pretty steady at 19. The average for the trip that included a decent amount of city driving getting the dolly and through N.O. was 16.4MPG.

The highest the trans temp reached was 201° after a ~1/2-mile (maybe longer?) ascent up the Mississippi River bridge. It settled at 172° once out of the city and cruising:

Home without a hint of issue:

 

[Sparksalot]

Over the last few days I’ve been able to confirm the auxiliary mechanical connection for the left fan harness works and both fans are now running properly when I’m crawling along dirt roads. I also noted the transmission and engine temps start swinging a bit when I’m doing about 30 or so. I’m guessing whichever module controls them shuts them off at a certain threshold.

 

[gooffeyguy]

Drove about an hour south for nieces graduation party. Had to get gas before heading back home and didn't see E85 nearby, so filled up with 93.

Took 24.8 gallons at $3.29 a gallon, so just under $82 total [emoji33]

Alcohol % before filling was 70%. On the way home it settled down to 15%.

I'll have to see if it changes any after a cold start tomorrow.

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