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How To Replace LB7 Turbo

durallymax

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How to Replace your LB7 Turbo
There may come a time in your Duramax trucks lifetime that you may need to either replace the turbocharger or upgrade the turbocharger. Whether it’s due to turbo failure or that urge for extra power, this write-up will guide you through the replacement of an LB7 turbo charger while the motor is still in the truck. 2001 model year trucks will vary slightly as will trucks with EGR.

As with all of my write-ups, this one was done off the top of my head since I never have time to create a write up while performing the repair on the truck as it needs to get done and out of the shop ASAP. So if you notice anything that I may have missed or something that needs corrections or maybe you just found a better way to do something, let me know. I also suggest you read the entire write-up thoroughly so you have an understanding of what needs to be done.

I created this write-up based off my personal knowledge with this topic and also using some things out of the GM service manual.

On a scale of 1-10 (1 being easy) I would rate this task at a 6. It’s not too complicated but it will kick your ass every time you turn around. The exhaust bolts don’t like to break loose, expect to break some tools and bruise some knuckles.

I will also add that if you plan to do an upgraded turbo and head studs, save yourself some time and hassle and just pull the motor. It will be much faster, trust me. I do have a write-up for removing an LB7 but it is currently not finished.

`Also another note, if you want to upgrade your turbo mouthpiece to a ported and polished one, order on prior to performing the repair as it will be a walk in the park during this job.

The parts you will need to replace a stock turbo charger are
New/Used/Reman Turbo
Oil Feed banjo bolt gasket
Oil Return gasket for turbo side
Oil return gasket for rear housing side
The exhaust gaskets are not supposed to be re-used but many do reuse them, if the bolts are torque properly I’ve had no issues reusing them, but if you want to replace them there will be four total that need to be replace for the up-pipes and one for the downpipe.
Sorry I don’t have part numbers at this time, but I will add them later if I come across them.

Tools Needed
11mm 6pt Deep Well
Various 12mm 12pt sockets/wrenches
17mm tools
And your basic tool set.

Removal Instructions
1.[FONT=&quot] [/FONT]As with any R&R disconnect the batteries just to add that extra level of security.

2.[FONT=&quot] [/FONT]Start by Removing the Transmission following my transmission removal guide. This will make your life ten times easier. I’ve never done one with the transmission in place, and I don’t know how people do it.
http://dieselhaulin.com/diy/Allison Removal Writeup.pdf
NOTE:This write up will be changing soon so that it is not in PDF format anymore, it will just be in a normal thread. Also plan on getting some better pictures.

3.[FONT=&quot] [/FONT]Now your passenger side tire and fender liner should be out from removing the transmission. At this point drain the radiator by removing the drain plug, and collect the fluid in a clean pail for reuse. If you leave the overflow bottle cap on it will drain slowly and be easier to control. If you can find and exhaust elbow or something to channel the fluid (I use and old drivers side CAC tube) your life will be easier and you can remove the overflow cap and let it flow out like crazy.
Radiatordrainwriteup.jpg

4.[FONT=&quot] [/FONT]If you haven’t already done so, disconnect the downpipe from the front pipe.
downpipewriteup.jpg

5.[FONT=&quot] [/FONT]Now remove the driver’s side wheel and fender liner using a 7/8” or 22mm for the wheel and a body clip removal tool set for the fender liner.

6.[FONT=&quot] [/FONT]Now remove the turbo resonator (the black piece that says 6.6 Turbo) by loosening the clamp that holds it to the air intake using a 5/16” or 8mm nut driver or a flathead screwdriver. To remove the rest of the way simply pull up on it and it will pop off. Now would be a good time to get a 2” test plug from the hardware store and plug the resonator port if you haven’t done so yet.

Turboresonatorwriteup.jpg

7.[FONT=&quot] [/FONT]Now remove the turbo heat shield using a 10mm to remove the three bolts that secure it.
Turboheatsheildboltswriteup.jpg

8.[FONT=&quot] [/FONT]The next step is to remove the downpipe heat shield using a 10mm to remove the three bolts. The finesse it out of the truck and set aside.
downpipeheatsheildwriteup.jpg

9.[FONT=&quot] [/FONT]Next remove the driver’s side up-pipe heat shield using a 10mm to remove the four bolts, then finesse it out of the way and set aside.
backofturbowriteup.jpg

10.[FONT=&quot] [/FONT]Now generously soak all of the up-pipe bolts and downpipe bolts with penetrating oil, do this a few times as you complete the next few steps. For a picture of where they are at see below.

11.[FONT=&quot] [/FONT]Next remove the air intake tube by unhooking the MAF sensor and loosening the clamp that holds it to the air box and turbo mouthpiece using a 5/16” or 8mm nut driver or a flathead screwdriver.

12.[FONT=&quot] [/FONT]Next you can remove the blue CAC tube from the turbo by using an 11mm tool to loosen the clamp, and then slide the hose off.
CACTubeTurbowriteup.jpg

13.[FONT=&quot] [/FONT]Another thing to get out of the way is the PCV tube that runs across the turbo mouthpiece. To do so slide the clamp off on the driver’s side valvecover and swing it out of the way.
TurboPCVDriversidewriteup.jpg

14.[FONT=&quot] [/FONT]You will also want to disconnect the MAP Sensor and the intake heater. The MAP sensor just simply unplugs and the intake air heater comes off with an 11mm I believe. Then swing the wires out of the way.
Wastegateline.jpg

15.[FONT=&quot] [/FONT]Next you’re going to want to unhook the coolant lines using pliers to slide the clamps back. The coolant feed line can be disconnected either at the turbo or at the upper coolant pipe, the coolant return line is buried down next to the turbo on the pass side and can be removed either from the turbo or from the hard line that it connects to on the other end. Some coolant may spill out, this is normal, but by draining the radiator you avoid a big mess.
TurboCoolantfeedwriteup.jpg

TurboCoolantreturnwriteup.jpg

16.[FONT=&quot] [/FONT]Now for the fun part, working from both the top of the motor and from underneath the truck, using various 12mm tools, remove all of the four bolts and two nuts that hold the downpipe to the turbo. Next using a 14mm I believe, remove the bolt that holds the downpipe to the passenger side up-pipe providing your downpipe bracket isn’t cracked. Now finesse the downpipe out of the truck. I will add that you may find it necessary to tilt the motor different directions to facilitate removal of the downpipe and up-pipes. This is assuming the transmission is out of the truck. See Below for pics.
downpipemountingboltwriteup.jpg


17.[FONT=&quot] [/FONT]Now you can remove the driver’s side up-pipe by removing the three bolts that hold it to the driver’s side manifold and the three bolts that hold it to the turbo using various 12mm 12pt tools and working from inside the driver’s side wheel well and under the truck, tilting the motor if needed. Set aside. See below for pics.
18.[FONT=&quot] [/FONT]Next you can remove the passenger side up-pipe using the same technique as for the driver’s side.
19.[FONT=&quot] [/FONT]Now the turbo oil drain needs to be removed. To do so remove the two nuts from the studs on top of the rear housing that secure the drain to it. The drain probably won’t slide off the studs at this point. You will need to remove it simultaneously when removing the turbo. Sorry couldn’t get a good picture of this but its just behind the “point” of the rear housing.
20.[FONT=&quot] [/FONT]Now remove the turbo oil feed line from the top of the turbo using a 17mm to remove the banjo bolt.
Turbooilfeedwriteup.jpg

21.[FONT=&quot] [/FONT]Now all that’s left is the turbo mounting bolts. There are three and they require 17mm tools. The rearmost bolt on the driver’s side is easily accessible from under the truck. The front bolt on the driver’s side as well as the bolt on the passenger side (which is also in front) are accessible from under the hood using extensions and swivels if needed. Sorry I couldn’t get a good pic of this.
22.[FONT=&quot] [/FONT]Now you can remove the turbo from the truck, if you have an extra hand, use it to finesse the oil drain off of the rear housing while the turbo is lifted out. It takes some finessing but it will come out. If the A/C line is in your way simply remove to A/C compressor from the motor and swing out of the way laying it on the passenger side battery. To do this, disconnect both of the wire connectors from the A/C compressor. Then using a ½” breaker bar insert it into the belt tensioner and release the tension on the belt to slide it off of the A/C compressor. Now using a 15mm remove the four bolts that secure it to the accessory bracket and swing it out of the way. And don’t forget the little clip on the fan shroud that holds the A/C line on.
23.[FONT=&quot] [/FONT]Once the turbo is out, swap over necessary parts such as the mouthpiece and oil drain. The oil drain has two bolts securing it to the turbo and requires a 12mm to remove them. The mouthpiece has three bolts holding it to the turbo and requires a 10mm to remove them.
24.[FONT=&quot] [/FONT]At this point it is time to reinstall everything, and as with all of my write-ups I just simply state to reverse the above. And see the notes and torque specs below.
Notes:
Make sure to replace the oil drain gaskets, they are not interchangeable so make sure the right one goes to the right place.
Also make sure to replace the oil feed banjo gasket
The up-pipe exhaust gaskets only go in one way, you will notice this.
Don’t forget the turbo heat shield. The one that sits between it and the block.
And also remember to pour new oil into the oil feed hole while rotating the shaft before installing the turbo oil feed line.
If you want the CAC tube to stay on better spray it with some hairspray before installing it.
Other than that it is pretty straightforward and don’t forget to put your coolant back in.

Torque Specs
25lb-ft/34N-m: Turbo Oil Supply Banjo Bolts
15lb-ft/ 21N-m: Turbo Oil Return Pipe Nuts/Bolts
80lb-in/9N-m: Turbo Mouthpiece Bolts
80lb-in/9N-m: Turbo Heat Shield Bolts
80lb-ft/108N-m: Turbo Mounting Bolts
39lb-ft/53N-m: Downpipe to Turbo Bolts/Nuts and all of the Up-Pipe bolts
71lb-in/8N-m: Downpipe and Up-Pipe Heat shield bolts.
53lb-in/6N-m: CAC tube Clamp (I go much tighter).
upipelayoutwriteup.jpg

Downpipe1.jpg
 
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