Toyota Highlander 3.5L Transmission Repair Information
Here you can find information regarding repairs of the Toyota 3.5L GF4A-EL transmission. In this guide we
will cover
the basic componenets and repairs involving the transmision. This information includes
the draining of old transmission fluid, changing of the transmission filter, removal of the transmission oil
pan, as well as filling in new fluid. We also touch on the subject of removing the
transmission from the vehicle. For more detailed transmission information please see the transmission section on
the website and find your corresponding transmission. During the repairs we will include
certain procedures that should be followed when performing the work as well as the torque specs for the bolts
involved.
Transmission filter replacement
The first step involved in replacing the transmission filter is to drain out your old fluid from the
transmission. To do this you will need to remove the transmission drain plug and let all of the fluid pour out. Be
ready with some containers to catch the fluid so it does not get everywhere. Once the fluid is all out you can put the plug back and torque
it to 25 ft-lbs and then start
to remove the 10mm bolts that hold the transmission pan to the transmission. With all the bolts removed you can remove the
pan and gain access to the trans filter. The filter is the black component pictured to the side. It can be removed by simply
pulling it off of the vehicle. To install the new one you simply just push it up where the old one was. Be sure to use a new o-ring and
to lube up the o-ring with atf fluid before installing the new filter. With the new filter installed you can replace the transmission pan
using a new gasket or some silicon sealant. With the pan in place you can start to hand tighten the pan bolts until all of them are in
place. The transmission pan bolts will need to be torqued to 8 ft-lbs in a cross pattern design. Once all bolts have been tightened and torqued
you need to fill the transmission with new fluid and the job is done.
Toyota Highlander Converter Drain Plug Torque Specs : 6 ft-lbs
Toyota Highlander Tranmission Pan Torque Specs : 15 ft-lbs
Engine Flexplate to Torque Converter Bolts
When reassembling the transmisson and engine together you will need to refasten the engine flexplate back up the
the transmissions torque converter. This can be done through a small opening on the bottom
of the bell housing. Through the opening you can access the bolt holes and insert one at a time while moving the
engine to access the others. Occasionally you may need to adjust the torque converter before
connecting to the flexplate in order for the bolts to line up. If everything is correct the bolts should screw
in easily with little resistance. These bolts should be torqued down to 20 ft-lbs to ensure none of them
loosen up when the engine is running otherwise you could end up with a major issue on your hands. Once all the
bolts have been installed and torqued you can turn over the engine to ensure it turns smoothly
and that there are no issues with the torque converter now.
Toyota Highlander Flexplate to Converter Torque Specs : 30 ft-lbs
Transmission Pan installation
The transmission pan transmission can be removed via a series of bolts that hold it onto the bottom of the
trans. To reinstall the pan you can use either the same gasket if
still in good condition or a new gasket and some silicon sealant to aid with it. Once the gasket is in place you
only need to replace the pan back up to the transmission and begin installing the bolts. These
bolts will need to be torqued to 8 ft-lbs to safely secure the pan to the trans. Once all have been torqued
then the pan is properly in place.
Engine to Transmission Bell housing bolts
When connecting the engine and transmission back together you will need to install a series of bell housing
bolts to make sure that the two larger components stay securely together. On the 3.5L
engine there is usually 6 to 7 of these bolts that are spread out around the outside of the housing. Each bolt
should be installed and then torqued down to 35 ft-lbs. While torqueing the bolts down be sure to
check that nothing is wedged between the engine and trans and that the torque converter is in its proper place.
Bolting these together without everything being in place can cause damage to componenets and potentionally
your transmission seal.
Toyota Highlander Bell Housing Bolts Torque Spec : 53 ft-lbs
