2021 Chevy Silverado 3500 6.6L Duramax Complete Torque Specs List
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Chevy Silverado 3500 6.6L Duramax Repair Information
Chevy Silverado 3500 6.6L Duramax Engine Repair Information
Here you can find information regarding the assembly of the Chevy 6.6L engine. In this guide we will
start from the inside of the engine including the
crankshaft, connecting rods, and piston ring installation and then move outwards all the way to the pulley belt
system. Along the way correct procedures and torque specs
will be given to aid in the assembly of the engine. Feel free to start from the beggining and work your way
outwards or skip ahead to your current position in the engine for what you may need.
Crankshaft Main Caps Installation
The 6.6L engine block main bearing caps should be inspected for any defects or flaws before installation.
Be sure to lubricate the bearing surfaces prior to installation. Once prepared you can place the caps onto the crankshaft
and begin tightening the bolts down in a multi stage process. To start off you can hand tighten up the main bolts and the corresponding
side bolts. From here you can torque down all of the main bolts to 72 ft-lbs then 97 ft-lbs followed by a 60 degree turn. Be sure to go through each
bolt one at a time through each step during the torquing sequence. You can start at the middle bearing cap and then work your way outwards. Next the
main bearing cap side bolts can be installed and torqued down to 52 ft-lbs. Be sure to also follow a middle outwards approach for these bolts as well.
Chevy Silverado 3500 6.6L Duramax Main Cap Bolt Torque Specs : 72 ft-lbs + 97 ft-lbs + 60°
Chevy Silverado 3500 6.6L Duramax Main Cap Side Bolt Torque Specs : 52 ft-lbs
Piston and Connecting Rod Installation
To install the pistons and connecting rods you must first install the piston rings into each piston. Be careful
not to stretch the rings or break them during installation. Make sure to put the correct rings in the correct
positions, this can be determined by looking at
the instructions given with the new rings. Each ring manufacturer is different so be sure to check for your
specific rings. Once the rings have been installed you can now fit the connecting rod bearings into the end caps
and lube them up with oil or lithium grease. The piston can now be lowered into the cylinder, make sure the dot
or mark is facing the front of the engine and that you don't scratch the cylinder.
Once installed you can match the connecting rod caps with the correct rods and start to torque the connecting
rod bolts to 47 ft-lbs and then an additional 30 degree turn followed by another 30 degree turn for each bolt. After all are done rotate the crank
to ensure all pistons move smoothly in and out of their cylinders and nothing binds.
When installing the oil pump be sure to use the proper sealant around the pump base if neccessary to ensure that oil pressure
doesn't drop due to leakage. Both surfaces should be cleaned and preped prior to installing. After preparing the contact surfaces carefully
install the oil pump onto front of the engine block right next to the crankshaft. On the duramax the oil pump will need to be installed prior
to installing the crankshaft reluctant wheel which is used to drive the camshaft and other componenets. With the oil pump in place you can tighten down
the pumps mounting bolts to 15 ft-lbs. From here you can install the oil pumps driven gear nut to 74 ft-lbs.
The first thing you must do when installing cylinder heads is to ensure both the block and head surfaces are
completely clean from dust, oil, and any debris. The next thing you must to is
to set the camshafts to their correct positions to prevent any valves from hitting pistons during installation
and torquing of the head bolts. Much the same you have to set the pistons to their correct
locations, typically this means putting the #1 piston to TDC or Top Dead Center. Once everything is ready you
can install the head gasket onto the engine block by aligning the alignment dowels.
Something I usually do is spray down the head gasket with some engine copper spray from permatex which you can
find here, this ensures that any gaps that could be present between the 2 surfaces gets filled with the
spray. It
also helps to transfer heat between the 2 metals. With the gasket in place you can set the cylinder head onto
the gasket and block, if needed have someone assist with this process as the head can be heavy
and you don't want to scratch anything or drop it! Once the head has been placed you will want to start
installing the head bolts to make sure it doesn't move. Be sure to buy new head bolts as many manufacturers
use TTY or Torque to Yield head bolts meaning they stretch during torqueing and cannot be used twice. Also make
sure to lubricate the bolts in clean engine oil before installing them into the head. On Chevy engines there is occasionally
bolt holes on the engine block that cross into water passages. Any hole that does this should be installed with some silicon sealant.
A little goes a long way in this step and you can check holes by shining a flashlight down them and looking in the water jackets.
Once all the head bolts have been installed and finger tightened you can start the torqueing process, almost all
head bolts have a multi-step process for torqueing. The 6.6L Duramax engine uses 2 different sized head bolts being 18 large ones and
4 small ones. The smaller bolts go on the outer side of the cylinder head and get tightened down to 18 ft-lbs. The large bolts are the main
cylinder head bolts and can be installed and torqued down to 37 ft-lbs and then 59 ft-lbs followed by two sets of 60 degree turns going
through each bolt during each step.
Be sure to tighten the right bolts to the right specs as this is a critical component of the engines functionality.
On the Chevy 6.6 Duramax engine the timing system is ran by the use of gears which run from the engines crankshaft to the engines camshaft gear.
Since the camshaft is located in the center of the engine it needs to be installed from the front side of the
engine. The camshaft bearings get installed using a special cam bearing installation tool. The tool simply presses the bearings in and out of the bearing holes
using different sized plates to press on them. Be sure that all of your camshaft bearings are in good condition prior to installing the camshaft and building the
engine as this is a critical part of the engine. If all bearings are good and in place the camshaft can be lubed and placed into the engine. It should slide
into the bearings with ease, if it gets caught do not force it as you risk damaging the bearings. Simply move the camshaft end around until it slides in. Once
all the way into the engine you will need to install the camshaft retaining plate and its bolts. Depending on your specific chevy engine the camshaft retaining
plate gets installed impediately after the camshaft is slide into place or after the timing gear has been installed. Depening on how you took apart your engine
and the new parts you are installing you will need to adapt accordingly. The retaining plate bolts need to be tightened down to 16 ft-lbs. The camshaft timing
sprocket simply slides onto the camshaft and can be tightened down to 173 ft-lbs. Be sure to hold the engine and camshaft well during tightening and to
have the crankshaft sprocket installed so that it holds the camshaft without any issues.
The timing cover on the 6.6L Duramax is used to cover up the internals of the engine and hold in massive amounts of oil. For this reason I recommend using
some silicon sealant along with a new gasket during installation. Be sure to clean all of the metal surfaces prior to installation and placing the silicon onto the metal.
With everything ready to install be sure to double check your timing and engine internals before placing the cover in place. Another tip is to lube up the
crankshaft seal with some oil so it seats better. If everything is good to go then place the cover
onto the engine block and begin to tighten down the bolts hand tight. Once all of the bolts have been set in place be sure to follow your sealants instructions by waiting the recommended
time. Once ready the timing cover bolts can be tightened down to 15 ft-lbs. Be sure to not overtighten these bolts as it can be easy to do so.
Much like the timing cover on the 6.6L the oil pan plays an important role in keeping the engine oil inside the
engine. For this reason I recommend using a new gasket as well as some silicone sealant
during installation. Using the same technique as before with the cover you clean the surfaces of both the oil
pan and the engine block and then install the new gasket onto the block and then follow
it up with some silicone sealant. Be sure to follow your sealants instructions to ensure you get the best seal
from your application. Before installing the upper oil pan be sure that the oil pan baffle and oil pump have been installed correctly.
The upper oil pan bolts on the 6.6L duramax tighten down to 15 ft-lbs and should be torqued in a cross pattern. Next the lower oil pan can
be installed using a new gasket and some silicon and torqued down to 8 ft-lbs. Finally the oil pans skid plate can be installed and torqued down to
15 ft-lbs.
The valve cover installation on the 6.6L Duramax is rather difficult as it also ties in the installation of the engines glowplugs and fuel injectors.
To start with installing these components make sure that your cylinder heads are both installed properly and torqued down to spec. Next the rocker arms
should be isntalled and the rocker arm shaft bolts can be torqued down to 30 ft-lbs. With that installed we can then install the guides for the engines injectors
and insert the injectors down into the head. From here we can torque them down to 37 ft-lbs and install the lower valve cover. The lower valve cover can be installed
using a new gasket and some silicon sealant to ensure it does not leak. The lower valve cover bolts can be torqued down to 8 ft-lbs. Next the injectors harness
can be installed and torqued down to the lower valve cover using 8 ft-lbs and the injector terminals can be installed and torqued down to 2 ft-lbs. The fuel
return line can then be installed and torqued down to 12 ft-lbs. Now the upper valve cover can be installed using a new gasket and some silicon sealant and torqued
down to 8 ft-lbs. Lastly we can install the engines glowplugs and torque them down to 13 ft-lbs.
Intake Manifold, Fuel Rail, and Turbo Installation
The intake and fuel system on the 6.6L Duramax is rather complicated and requires a good amount of knowledge regarding engines in order to
comprehend what is all going on. To help explain this procedure and the components involved I will start at the base setup of the engine as if
you were building it from the beginning. Starting with the lower intake to the cylinder head you can install these using new rubber gaskets and some
silicon and torque them down to 15 ft-lbs. Next there is a Y intake tube which connects both of the lower intake manifolds together. The bolts for this
tube can be installed and torqued down to 8 ft-lbs. Next the fuel rails can be installed onto the lower intake manifolds and torqued down to 18 ft-lbs.
Following the fuel rail installation you can install the fuel pipes which run from the rail to the fuel injectors within the valve covers. These feed lines use
nuts which connect themselves to each point of the system. These feed nuts need to be tightened down to about 30 ft-lbs. From here we can install the remaining
fuel lines which run from the fuel rails to the fuel system. These remaining pipes can be torqued down to 15 ft-lbs. The fuel injection control module itself can
be torqued down to 15 ft-lbs. Finally the turbo charger and its inlet pipe can be installed. Starting with the turbocharger it uses 3 main bolts
which tighten itself down to the engine block using 80 ft-lbs. Next the turbo has both an oil supply and return hose as well as a coolant pipe.
The turbochargers oil supply hose can be torqued down to 25 ft-lbs. The oil return line tightens down to 15 ft-lbs. Finally the turbos coolant pipe can be installed
and tightened down to 15 ft-lbs.
The exhaust manifold can be installed by cleaning the surface areas on both the head an the manifold itself and
then by using the exhaust manifold gasket and putting it in place. Once the gasket is in its
location you can put the manifold onto the heads and begin to torque it down to 28 ft-lbs. I always use some
copper spray from permatex on the exhaust manifold gaskets to ensure I do not end up with
any exhaust leaks once done. From the manifold out the exhaust pipe connects to an outlet pipe which runs the exhaust gases from the turbocharger.
The exhaust outlet pipe bolts can be tightened down to 39 ft-lbs.
The water pump on the Chevy 6.6L Duramax engine is gear driven and installs onto the front of the engine block on the right hand side. It has a few bolts which
tighten down into the front engine cover and then a coolant pipe that runs to the rear side of the engine. The pump should always be installed using a new gasket
and some silicon sealant to ensure that neither oil or coolant leaks out of the engine. Once prepared you can install the water pump onto the engine and hand tighten
the bolts. Once hand tightened be sure to wait the amount of time depending on your sealants manufacturer information. Once ready you can torque down the water pump
bolts to 15 ft-lbs. The outlet on the rear end of the water pump can be tightened down to 18 ft-lbs. On the front end of the engine there
is a coolant thermostat housing which ranges across the entire front end of the engine. It contains an inlet pipe from the water pump as well as 2 sets fo 4 12mm bolts
on each cylinder head. All of the thermostat housing bolts can be torqued down to 18 ft-lbs.
Most of what is left on the engine is just place and tighten objects such as the belt pulleys, belt tensioner,
throttle body, oil filter neck, crankshaft pulley, and motor mounts. If the items have a gasket and hold either
oil or coolant inside the engine then feel free to add some sealant along with the gasket. Always be sure to
inspect your gaskets and replace them if there is any deteriation or flaws with them. For the
belt system the crankshaft pulley gets torqued to 74 ft-lbs and then a 105 degree turn. The belt
tensioner can be tightened to 30 ft-lbs and the idler pulley can also be torqued down to 27 ft-lbs. When installing be sure they
both turn smoothly and if they do not then replace them with new ones as the bearings can go bad. The engine
motor mount can be installed onto the engine block if it hasn't been already, the torques for
the mount to the block is 37 ft-lbs and then when installing the mount to the vehicle or frame it can be torqued to
59 ft-lbs. Finally the throttle body can be installed on top of the intake manifold
with a good gasket and some added sealant using 7 ft-lbs in a criss cross pattern. For installing the belt you
can use a tool to move the tensioner into its springed state and install the belt as shown in the
picture. The power steering pump and its pulley should be tightened down to 37 ft-lbs. The alternator has a front bracket which can be
torqued down to 37 ft-lbs. The Air Conditioner Compressor can be torque down to the engine using 37 ft-lbs.
