How to Remove & Replace the Transaxle

Last Updated - September 7th, 2004


So you bought yourself a new clutch.  Or perhaps you blew your transmission and need to put in a new one.  Or maybe you just got yourself an ultra light weight aluminum flywheel.  Now you're asking, "what do I do next?"  Well, you asked for it.  Here's what you need to do.

Difficulty:    

Time Investment:  Weekend  

This is being rated as a weekend project because of the number of places you can get hung up.  You'll be removing some very tight bolts and prying some things apart.  You may break sockets, wrenches, or bolts, and you may not get the clutch disc aligned properly on the first couple tries.  If you use air tools, know what you're doing, everything goes smoothly, and you have someone to help you, you're still looking at a solid 14 hour project.

Note:  This page is written from the perspective of replacing a manual transmission.  Replacing an automatic will be similar but not exactly the same.


Go to Pictures:

Go to Instructions:

Go to Tools Required:
 

Go to Supplies to Remember:

Pictures:

Click on a picture to enlarge it.  

Please also note that these pictures are from different cars.  Most were taken of Mike's ES during a complete engine swap.  Others pictures are componets of the IROC.  Others came from Daytonastein.  You'll notice that the heads and exhaust manifolds are off in some of the pictures.  You do not need to remove these components to replace your clutch. 

This is a shot of the fan looking down to the lower radiator hose.
Here's a shot of the shifter cable bracket.
Here's a shot of the wiring around the throttle body.  (TPS, AIS, & Vacuum Tubing)
Here's the battery tray without the battery.
This is a shot of the 2 vacuum hoses that go into the side of the box connected to the battery tray.
Here's a shot of the connectors in the wiring harness behind the battery tray.
Here's a shot of the reverse light plug and the clutch cable.
Here are the shifter cables and  bracket.
This is the clip where you must disconnect the clutch cable.
Here's a shot of the bobble strut and bracket.
Here's a demonstration picture of how the T-brace is set up to support the engine while the transmission is disconnected and lowered.
This is the front motor mount.  The red wire goes to the starter.  The other wiring hanging down with the loose plug goes to the cooling fan.
Here's a shot of the front motor mount from below.
This is the starter sitting inside the front motor mount.  The red wire going to the small nut and the wire connecting to the larger nut above it must be disconnected.
Inside the driver's side wheel well is a plug to enable you to access the transmission mount.
Removing the plug reveals a bolt.
Lowering the transmission and engine while connected reveals some additional transmission mounting bolts.
This is a shot of the sling being used to lower the transmission.
Here's another shot of the sling as seen from below.
This bracket sits on the back side of the engine and holds the transmission to the engine.
This bracket sits in front of the engine and holds the engine to the transmission.
This is the water outlet on the driver's side of the engine.  Note the 2 bolts running through the transmission bell housing.
The transmission is lowered to the floor.
Kelly-Mulhern transmission install pins.

Kelly-Mulhern transmission install pins in place for transmission reinstallation. The plug at the left side of the end of the transmission is used to fill the transmission with oil.
Here's a picture of an "oil bong" made from a piece of tubing and a funnel.



Instructions:

Since you'll be removing a lot of components, it helps to keep the nuts/bolts that go with each part together.  Laying everything out in groups on the floor is very helpful.

1. Position the car.
Park the car in an way such that an engine hoist can be moved in front of the car and later removed.  You will also want to make sure you have plenty room around each of the front tires.  Don't jack it up yet though as it's easier to work under the hood with the car on the floor.

2.  Disconnect and remove the battery.  Put it some place out of the way.

3.  Remove the air box, air intake plumbing, or open element air filter.

4.  Disconnect the throttle cables from the throttle body AND the bracket that hold them away from the throttle body.

5.  Disconnect the AIS & TPS and any vacuum tubes from the throttle body.

6.  Loosen front lug nuts, jack up the car, put it on the jack stands, and remove the tires.

7.  Drain the coolant by disconnecting the radiator hose on the driver's side.

8.  Remove the radiator fan.

9.  Remove the coolant overflow tank.

10.  Remove the air dam.

11.  Remove the battery tray.
There are 5 bolts holding the battery tray on.  One is in the tray itself.  One is on the side and can be accessed from the top.  One is at an angle inside the middle of the tray.  One, from underneath the car, is up high and to the left.  You can't see it easily, but you can feel it.  The other, from under the car, is high right and visible.  In addition to the bolts, there are also two vacuum lines attached to the side of the tray.  

12.  Unplug the wires next to the computer next to where the battery tray was.
Pull the plugs apart and just push the wires out of the way.

13.  Disconnect the reverse lights.
This is a plug mounted on the top of the transmission.

14.  Disconnect the heater hoses.
These can remain connected to the heater core, but remove them from the engine.

15.  Disconnect the shifter cables on the top of the transmission.
The ends of these cables generally just pull off of the stud that they sit on.  If someone added an E-clip, you can remove it with a screwdriver.

16.  Disconnect the clutch cable.
Take note of the hole that the cable goes through for reinstallation.  Pull downward on the end of the cable using a pair of pliars.  Using a second pair of pliars, pull the metal "U" shaped retainer off the end of the cable.  The cable will slip easily back up through the rubber bushing.  Don't lose the retainer or the bushing.

17.  Remove both halfshafts.  (See the Halfshaft removal page.)

18.  Remove the bobble strut.
If you don't have a solid bobble strut, this may be a good time to upgrade.  The stock bobble strut is a little shock absorber with a threaded end held in place by a nut.  The nut will be rusty, and there isn't much leverage to be had around it.  If you just turn the nut, the shaft inside the strut will also turn accomplishing nothing.  The easiest way to remove it is to grind the entire head off with an angle grinder.  Don't waste your time with a Dremel.

19.  Disconnect the speed sensor.  
This is on top of the differential housing.  Either reach down from the top or up from the bottom.  It can be done both ways.

20.  Remove the bobble strut bracket.
The bracket is held in place by 2 bolts that are really difficult to get to.  Both must be removed from underneath the car and the range of motion you have to work with is pretty tight.  This is a good use for a ratcheting box end wrench.

21.  Remove the shifter cable bracket.
This bracket has a nut that hooks to a stud on the transmission and two bolts.  You can get the nut from the top.  One of the bolts can be accessed with a long exention from the driver's side wheel well.  The other bolt is best reached from underneath the car.

22.  Hook up the engine to the T-Brace.
Hook the end of your chain up to one of the bolts on the front driver's side corner of the engine.  The bolt used to connect to the grounding wire is a good choice.  You can put the bolt right through one of the links into the side of the front head.  Put the T-Brace in position and set the end of the leg up on top of a bottle jack.  Extend the bottle jack about 2/3 of the way up.  (It will be used to lower and then raise the engine back to the normal position.)  Wrap the free end around the leg of the T-Brace several times and connect it back to the end you connected to the head with a removable link.  Keep the chain as tight as you can when doing this.  The goal is to make the engine hit its normal height when the bottle jack is extended.  Pre-extending it only 2/3 of the way will help account for the slack you couldn't get out of the chain by hand.  This is easier to do than it is to describe.  Once you've got it, pump the jack a couple of times so the engine is clearly being supported by the T-Brace.  

23.  Remove the front motor mount from the frame.
Remove the two nuts and one bolt from the frame under the radiator as well as the through bolt and the front  mount insert.  These nuts and the bolt will have some rust.  An impact wrech works great here.

24.  Remove the rest of the front mount from the engine.
First, get a good look at how this is on there.  During reassembly you will likely scratch your head to remember which way it goes.  There are a few bolts holding this bracket onto the transmission, the most notable is one that is threaded on both ends and has a nut that holds the mounting bracket on.  Removal should be self explanitory.

25.  Remove the starter.
There are 2 wires going to the starter.  To remove these, you'll want your 1/4" drive ratchet and sockets.  One of the bolts protruds a little so use the technique of putting the socket on the nut and partially inserting the wrench into the socket.  Don't lose the nuts or the little rubber piece of tubing that covers the end of one of the studs.  Once the wires are off, you can remove the bolts holding it in place.  Once those are out, the starter should pull easily out of the hole in the transmission.  At this point, the dust guard will probably fall out from between the engine and the transmission.

26.  Remove the transmission mount.
This mount is accessable from the driver's side wheel well.  Pull out the rubber plug in the wheel well to access one of the bolts.  Then, you can lower the bottle jack to drop the engine and transmission into a position where you can access the other bolts holding on the mount.  Once all of the bolts are out, lower the bottle jack a little more and pull the mount out.

27.  Remove the wire bolted to the rear cover of the transmission.
Just remove the bolt the wire is connected to through the driver's side wheel well.

28.  Lift the bottle jack back up to put the engine in the normal position.

29.  Set up the transmission sling.
(Note:  The linked picture is of a car with the heads off.  You do NOT need to remove the heads to remove the transmission.  Just look at the sling itself.)  Move your engine hoist to the front of the car and lower the hook to the top of the transmission.  Make a loop in the end of a piece of aircraft cable (plastic coated steel cable) and clamp it off.  Put that loop around the hook.  Now take the free end and run it down under the trans as close to the bell housing as possible and bring it back up on the passenger side of the differential.  Feed the end back through the hook and then take it back down through one of the holes where the clutch cable goes.  Pull the cable through that hole and bring it back up on the other side of the transmission.  Feed the end through the hook one more time and clamp it to one of the other cables.  At this point, you should have a sling that can support the transmission once you unbolt it from the engine.  Raise the hoist enough to put some tension on the cables.

30.  Remove the front brace and rear braces.
These two braces are triangular in shape and have 2 bolts each that go into the engine and a single bolt that goes into the transmission.

31.  Remove the remaining transmission mounting bolt under the car.
Aside from the two braces, there should be a bolt up behind the differential housing.

32.  Remove the top side transmission mounting bolts.
Your best bet here is probably a 1/2" ratchet with an extension.  2 bolts hold the water outlet that goes to one of the radiator hoses.  There is one other bolt on each side of those.  For one or two of the bolts, you may want to loosen the sling but keep in mind that it is pretty much all that is supporting the transmission so don't undo all the bolts with it loosened.  Once all of the bolts are out, the transmission should literally swing outward.  If not, give it a tug and it will.  If you have to pry it, you missed a bolt.

33.  Remove the transmission.
Once your transmission is free, lower it to the floor with your hoist.  If you have a creeper, it is handy to lower the transmission onto it and use it to wheel the transmission out from under the car.  Otherwise, you can drag it by the sling.  As you lower the transmission, you'll also have to guide it so that the differential doesn't get hung up.  This may take a couple of tries.  

34.  Perform any activities needed in regard to the clutch disc, flywheel, or throwout bearing.  (See the clutch page.)

35.  Install two Kelly-Mulhern Performance transmission alignment pins.
This is an optional way to make re-assembly easier.  After you hoist the transmission back up, you have to get it aligned right and get the input shaft to go into the clutch disc.  If the transmission is too high, too low, to the right, or to the left, you won't hit it.  If the clutch disc isn't aligned properly you also won't hit it.  These pins allow you to eliminate the first variable and make sure everything but the clutch disc is properly lined up.  Screw one pin into the front most hole and one into the top back hole.

36.  Reattach the transmission sling.
This is easiest to do if you put the back end up on a wood block so that it sits level.  Your goal is so that when you hoist it up, it sits level without twisting.  If it doesn't hang level or gets rotated, it is about 100 times harder to work with.  We've done it both ways (un-level & rotated and also level & pretty close to the right rotation).  You are advised to get it on the sling right from the beginning.

37.  Reattach the transmission.
Lift the transmission back up with your hoist.  If you set the sling right, it hang close to level with the bell side slightly elevated and not be rotated too far out of wack.  If it is rotated, you may be able to reach down from the top and pull up on one side while holding down on the other.  If it won't budge, lower it and adjust the cables.. 

You may have a little trouble getting the transmission by some of the parts of the frame.  We've had them go in quickly and had them take several trys.  Just look at what you're hitting and adjust as needed.  If the oil plug end is higher than the bell, you won't stand a chance here.

With alignment pins:
Trans alignment pins allow you to line everything up perfectly and slide the transmission onto the engine.  Experience has shown that there isn't a perfect way to do this because the clutch disc is rarely aligned perfectly.  Success has been had installing 2 pins one in a lower front hole and one in the rear water tube hole of the engine.  It has also been had by using a single pin in the rear hole behind the rear water tube hole.  In another attempt, a pin was screwed into the transmission and slid through one of the front mounting holes on the engine.  Having had some problems with clutch disc alignment, no two installs Mike and Ed have done have gone quite the same way.  Thus you'll need to experiment a little and see what works best for you.

Bring up the trans so that the pin(s) are aligned with the appropriate hole(s).  Adjust the rotation as necessary and push the transmission onto the pin(s).  You may be able to do this from above although it's sometimes easier to see what's going on and lift up the rear end from below.  If  the clutch disc is aligned correctly, it may go right on.  Having a second person handy to hold the transmission in place is handy so that you can get underneath and do a little pushing/wiggling.  Usually, you need to lift the far end of the transmission up to make it level.  If after a lot of wiggling it still won't go on,  use a pry bar to rotate the flywheel a few teeth.  (the splines inside the clutch disc must mesh with the transmission shaft.)  Try again.  You may need to do this 3 times.

If you're using two pins, and it hasn't gone on yet, remove one to give you a little more wiggle room and try again.  You may also want to try using one pin in one of the far side holes rather than in one of the more obvious top holes.

If the transmission still won't go one, carefully remove the remaining pin without rotating the transmission, lowering it, or raising it.  Get underneath and again try to slide things together.  Then do some more wiggling.  The range of motion isn't limited here so if the clutch disc is just a little bit off, you may luck out.  Be careful not to let the transmission rotate too much though or you'll have trouble lining things back up.  If it won't go, rotate the flywheel a few more turns.  If after this, it still won't go on, lower the transmission back down and realign he clutch disc.

Without the alignment pins:
If you don't have the pins, do your best with the alignment dowels on the engine (marked with yellow paint in the alignment pin picture.  You won't be able to line things up vertically although you can get it close.  Set the transmission so it's a little lower (maybe an inch or less) than it needs to be.  Get underneath the transmission and bench press it upward.  Move it around and try to find the hole in the clutch disc.  It helps to have someone topside to tell you which way the transmission is rotating and what direction to move it in (right, left, up, or down).  At this point you're guessing on location.  This can take awhile to hit the spot.  If you can't get it, use a pry bar to rotate the flywheel a few teeth and try again.  You may need to do this a few times.  Also, you will often find that lifting the far end of the transmission up more makes it easier to slide on.  If you still can't get it, rotate the flywheel by a few teeth and try again.  You may want to do this up to 3 times.  If it still won't go, you'll need to try realigning the clutch disc.

Regardless of method:
Regardless of how you do this, sometimes things don't line up the first several times you try it.  It is frustrating.  You'll get tired.  Try rotating the flywheel a by a few teeth.  Try wiggling the trans in with the far end elevated.  If you can't take it anymore, take a break and come back to it.  Sometimes you'll get it on the first try.  Sometimes you'll get it on the fifth. 

Once the transmission goes on, you'll want someone else to start one of the bolts while you hold the transmission in place (otherwise it tends to fall off the engine).  


38.  Put everything else back together in the reverse order.

39.  Fill the transmission with oil.
Pull the plug in the side of the transmission.  Using a funnel and a piece of tubing, fill it with 2 quarts of motor oil.  When you're finished, stick your finger in the hole and make sure you can feel oil.  Then replace the plug.

Tools Required:     


Supplies to Remember: