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Old 03-09-2010, 01:51 AM
durallymax durallymax is offline
Tech Specialist
Join Date: Mar 2010
Posts: 73
How To Remove LB7 Duramax

How to Remove your LB7 Duramax
So you need to pull your motor out eh? Either you blew it up or have a lot of go fast parts to put in it or both. Or maybe you are just curious as to what all is involved in removing one. Well this is a general guide to removing the LB7 Duramax motor. I will try to make this very thorough and explain every little detail like my other write ups. This guide may not necessarily be the same way everybody else does it, or the 100% correct way, but it is the way I do it and it works out well for me. This is off of the top of my head for the most part so some things may be missing or need some editing, I plan to update parts of it in the future as needed. BIG THANKS TO TOM (THEBAC) FOR THE PICTURES you will notice most of them are from him. Thanks a bunch man for taking time to do what I am always to lazy or in a hurry to do.
For starters some of you reading this may not think you will ever need to pull your motor. However I can say that if you plan to do something like a turbo swap and head studs at the same time, removing the engine will make things much easier and will give you less chances for things to go wrong, again just my opinion though.
Your probably wondering, do you need to be a full time mechanic? Not necessarily, I would say this is for people with moderate experience, but the biggest part is having some experience and knowledge and just being comfortable with removing your motor and realizing that hey, sometimes youíll mess up but thatís how you learn and in the long run you are still saving money.
So what all is needed to remove it? If you have access to a car lift it will make things nice but it is not necessary. A cherry picker(engine hoist) is a must and you will want one that has a long reach and extends fairly high in the air, also make sure it can handle the weight of the Duramax about 1,100lbs assembled if i remember correctly. For the rest you will need basic hand tools mostly metric from 8mm-19mm. The only really special tool you will need are some fuel line disconnect tools, which are cheap and available everywhere.
Now letís get started.
How To Do It
1. If you have a lift it I like to remove the transmission, to do this refer to my transmission removal guide. However if you prefer to leave the trans in the truck then remove the torque converter bolts before doing much else. To do this remove the starter by using a 15mm to remove the two mounting bolts and then just lay it out of the way then using a 15mm you can remove the bolts either with a small ratchet or a lot of extensions and a swivel on an impact. Have a friend line up each of the 6 bolts with the access hole by using a 24mm on the alternator nut and turning counterclockwise. However the correct way to do this is to turn the balancer bolt with a 36mm clockwise. Then towards the end of the removal procedure support the trans by the pan and unbolt the trans from the motor using a 13mm to remove the accessories which include the dipstick tube bracket (2 nuts on passenger side), transfer case vent tube(1 nut on top of trans) and the fuel line bracket (1 nut) on the drivers side. Then use a 15mm to remove the bolts. There are 9 of them. When finished support the transmission with a 2x4 across the torsion bars, this will be more secure than a bottle jack/floor jack and will leave your truck manuverable to free up the bay.

2.Now that you will have the passenger side tire and fender liner out of the way, go to the drivers side and remove the wheel and fender liner on that side using a 22mm or 7/8" socket and body clip removal tools if you have them. There are wiring harnessess that fasten the to the fender liner so be sure to unhook them.
3.Now raise the hood into the service position. I suggest getting a helper, the hoods heavy. If you are tall like me you can hold it by hand and use your head to support it while installing the nuts and bolts. To do this first remove the ground wire running from the firewall to the hood using a 10mm then remove the bolts that connect the springs to the hood using 13mm tools and then flip the hood so that it is perpendicular to the floor, now you should be able to put the bolts through the service position holes in the hood and into the springs. And you now have plenty of room and light to work with, without removing the hood.

4.Now you will want to disconnect the frontpipe if you havenít already using an 11mm deep well. These are locknuts so an air ratchet will help save your hands.

5.If you do not have your batteries disconnect yet, disconnect them using an 8mm wrench.
6.Now you want to remove your air intake tube by unplugging the MAF sensor, and loosening the two clamps on each end of the tube using a 7mm. NOTE: On 2002-2004 LB7s there will be an additional clamp which goes to the turbo resonator, this will need to be loosened as well. On stock setups the air box wont be in the way.
7.Now we want to drain the radiator, to do so there is a plug on the lower passenger side of the radiator that you can remove to drain it, it does not have a hex head or anything, just simple use a pliers to loosen it, it is not very tight. But prior to draining the radiator make sure that you have a way to channel the fluid into a container. I like to use the aluminum section of an old drivers side CAC tube I have laying around. But basically you need something to get the coolant to flow down instead of straight out. Once you get a way to channel the fluid, remove the cap from the overflow bottle to speed up the drain time. Reinstall the plug for now.

Front Clip Removal
1.Start by removing the radiator stack plastic cover by removing all of the body clips. This is the plastic piece that sits on top of the radiator stack/grille and has the belt routing diagrams on it. If you have a winter front you will have some screws to remove in lieu of some body clips.
2.Now you should have access to the one bolt and snap in tabs that hold the grille on. Remove the bolt using a 10mm, then compress the 4 green tabs that mount the grille to the headlight towers and pull them out. The grille is also fastened to the fenders on both sides. Remove the grille from these two points. You can get acess to these from inside the fender well. With these disconnect you should be able to finesse the grill assembly off. This is for GMC Grilles, Chevys may be different.
3.Now with that out of the way you can remove the 3 bolts holding the hood latch on using a 10mm. There is also a spot where the cable has a push in Christmas tree style holdown that you will want to yank out. Then swing the assembly to the side out of the way. NOTE: If you do not see where the bolts originally were, make marks, this is essential so that the hood latch lines up right upon reinstallation.

4.Now you want to remove your headlight assemblys. Many should be familiar with this but if not, there are pins that hold the headlights in. On GMCs there are two vertical pins, simple rotate them 90* and pull them up. On Chevys there is on horizontal pin, again simple rotate this pin and pull it out. Then disconnect the harnesses from the light bulbs.
5.Now remove the marker lamp assemblys. To do this compress the push in tab on the outside of each assembly the swing it forward and out. Now remove the 3 bulbs in it and set the assembly aside.
6.Now you will want to remove the Headlight support towers. These are held on with a few bolts requiring a 10mm, and each side has 2 bolts requiring a torx bit. Remove both sides and set aside. Both sides are mirrors of each other, the pic below is the drivers side.

7.Now you will have one wire left, it is the outside air temp sensor which is mounted on the radiator support A-Frame tower, disconeect the wire and the tabs that hold it to any part of the front clip along its path and swing it to the side out of the way.

8.Now your pretty much done but still need to remove the upper fan shroud. To do this you will first need to remove the TCM. To do this remove the two bolts that secure it to the radiator brace using a 10mm. Next simply unplug both of the connectors and set the TCM assembly aside. Now remove the 4 body clips that connect the two halves of the shroud, there are two on each side. Next pull the A/C line out of its mount on the passenger side of the upper fan shroud. Finally, remove the rest of the bolts that fasten the shroud to the radiator brace then remove the shroud and set aside.

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Old 03-09-2010, 01:53 AM
durallymax durallymax is offline
Tech Specialist
Join Date: Mar 2010
Posts: 73
Radiator Stack Removal
1.Now its time to get messy. First we will remove the drivers side CAC tube. To do this you will need to disconnect the long 90* silicone elbow from the turbo as well as the aluminum section of the CAC tube on that side using an 11mm deep well then remove this from the truck and set aside. Next remove the clamp that holds the other side of the aluminum section to the elbow on the intercooler using an 11mm deep well. I like to leave the elbow on the intercooler to make reinstallation easier.

2.Now you need to remove the passenger side CAC tube. To do this remove the band clamp at the intake bridge of the motor using an 11mm deep well. On this side I like to remove the elbow from the intercooler as it makes it easier to remove the radiator hose later on. But leave it connected to the CAC tube for easier reinstallation. Again remove the clamp using an 11mm deep well socket. Then fish the tube out and set aside.

3.Now lets get the tranny cooler out of the way. The first step is to remove the lines from it. To do this slide the pastic covers off of the fittings then using a small scredriver or pick, remove the little clips that hold the lines into the fittings. Now pull the lines out and use a small cup to catch the oil that drains out, it isn’t much but enough to make a small mess. Next reinstall the little clips back into the trans cooler fittings. The lines will push back in without removing the clips upon reinstallation, plus this way you dont loose them. Now remove the two bolts that fasten the cooler to the A-frame brace using a 10mm and then remove the two body clips that also support it. Now pivot it out and set aside. It will continue to drain out some fluid just so you know.
4.Now you can remove the big A-Frame brace using a 10mm to remove the 2 bolts at the bottom of each leg and the 2 bolts at the top that hold it to the radiator support. Youll need to come in from the rear. :D The picture below shows it removed but you can see the outline of where it once was.

5.Now you will to get the A/C condensor out of the way. If you have a refrigerant service machine, evacuate the A/C system at this point. Then unbolt the lines from the A/C condensor then remove the two mounting bolts with a 10mm and remove it from the truck. If you do not have a refridgerant service machine, just remove the two mounting bolts and then swing the condensor out of the way. It may be neccessary to slightly bend the lines to get adequate clearance later on in the removal process.

6.Lets get the radiator disconnected starting with the hoses. Removing the driver side radiator hose, remove it completely from the engine by removing both of the clamps and set aside. Next remove the lower radiator hose but leave it attached to the water pump as it is easier to get off with the radiator out of the way, you may want to set a catch pan under the hose as it will puke out some coolant. Now you will want to remove the two tranny cooler lines that run into the radiator in the same fashion as the others. Now remove the coolant overflow hose from the radiator as well.

7.Now we need to remove the radiator top brace. Start by removing the cross brace that runs over the drivers side battery using a 10mm. Next remove the 3 bolts on the underside of it at each end using a 10mm. Now you can either leave it attached to the radiator stack or remove the two bolts that hold the assembly to the brace using a 13mm.

8.Now we can finesse the radiator/intercooler out of the truck. But, first remove the drain plug once more and have somebody channel the coolant as you tilt the radiator to drain the remaining coolant out. Swing the a/c condenser to the side to make some room. Now remove the assembly and set to the side.

9.Now the lower fan shroud can just be pulled out and set aside. See Picture Above.
10.You can also remove the lower radiator hose now from the water pump using a 5/16” or 8mm. Removing the splash gard with a 15mm (5 bolts) will get it out of the way so a bucket can catch the coolant. Also remove the heater hose from the aluminum heater line on the passenger side of the engine. And since we are removing heater lines, do up to the top of the engine back by the firewall and disconnect the heater lines.

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Old 03-09-2010, 01:54 AM
durallymax durallymax is offline
Tech Specialist
Join Date: Mar 2010
Posts: 73
1.And now the front stack is out of the way. And now lets work on the wiring.
2.There is just a small wiring harness that needs to be disconnected and swung out of the way. Start at the passenger side and work your way over. Starting with the plug that is plugged into the A/C dryer, then the coolant overflow bottle plug (low coolant sensor), then the Alternator, then the two plugs on the A/C condenser. Also unhook the wires from the bracket that secures them to the thermostat housing. Then disonnect the two big bale connectors. You will also need to disconnect the “HOT” wire that connects to the back of the alternator using a 10mm. Also, you will need to disconnect the “Hot” wire that feeds the glow plugs using a 13mm. And finally, disconnect the firewall ground at the rear of the drivers side of the motor using a 10mm.

3.Now lets get the A/C Compressor out of the way. If you have already decharged the system you can remove the lines like Tom did and leave the A/C compressor attached to the motor. But if you did not decharge the system then you will need to remove the serpentine belt and then remove the 4 bolts with a 15mm and swing it over so it rests on the passenger side battery.

4.Now lets go underneath and remove the wires down there. Starting on the drivers side. There is one ground to remove using a 14mm. Then on the front of the motor remove the two bolts holding the plastic wire support onto the oilpan using a 10mm. Then remove the 2 ground bolts on the passenger side using a 14mm. Then remove the nut holding the starter wires and tranny cooler lines to the stud on the oil pan using a 10mm. Now your done under there.

5.Now lets remove the little red box that is supposed to be used as the positive terminal when charging. It has one bolt that holds it on, remove it using a 10mm.

6.The power steering pump will be in the way for removal so its easiest to just get it out of the way. You can remove it completely by disconnecting the lines or just unbolt it from the engine and lay it aside as Tom did. To do this remove the two bolts on the backside of the pump using a 15mm. Then remove the three out front using the 15mm as well.

7.And now were ready to pull the motor out. Get your cherry picker in position. I recommend the use of an engine leveler as well. Hook the chain or engine leveler up to the back of the passenger side of the head where you will find a lift tab. Thread a bolt into it. It’s an M10x1.5 thread which is a very common bolt. Then for the otherside take one of the A/C compressor bolts and thread it into the slot where the dual alternator or dual CP3 would sit. Tom’s engine leveler is a 4 chain setup, so you can hook it up his way as well if you have a similar setup. Now level the motor out and lift up until there is slight pressure on the motor.

8.Now on both sides of the motor there will be three bolts. Use a 15mm and remove all of them. Sorry I do not have a picture of this in the truck, but the picture below will show you how the mount is, both sides are the same.

9.Now the motor is free. Lift it up and move it forward then lift it up some more. And make sure that theres nothing connected to it and that it isn’t snagging on anything. A buddy or two or your kids, work good for this sometimes, then just keep playing with it until it comes out.

10.Now its out. Remember not to support it by the rear housing if putting it on an engine stand. To put it on an engine stand get 4 bolts thread M12x1.75. I like to just remove the slexplate and flywheel and then remove 4 of the rear housing bolts and then bolt through the rear housing into the block to attach the engine to the engine stand so that I can remove the oil pans on the stand versus laying under the engine. Then later on during dissasembly if the rear housing needs to come off, remove the engine from the stand, remove the rear housing and then bolt the engine back up.

I hope this helps some of you when it comes time to remove you engine whether you are happy about removing it or not. Like I said its not 100% perfect and I plan to update it with some more pictures later. Also if you see anything I missed or have a better way of doing something let me know.
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Old 03-09-2010, 02:10 AM
durallymax durallymax is offline
Tech Specialist
Join Date: Mar 2010
Posts: 73
Sorry for how all of the numbers got mixed up apparently this happens with multiple posts.

I hope to edit it later with the pictures at a set size so the post is easier to read, and also make some more spaces in between things.

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Old 03-09-2010, 10:08 AM
durallymax durallymax is offline
Tech Specialist
Join Date: Mar 2010
Posts: 73
Forgot this part

Here is the fuel lines disconnected. This will also need to be done prior to removing the engine. Also they have a bracket that holds them to the valvecover, remove the nut that holds the bracket onto a stud then swing the fuel lines out of the way.

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