If you’re wondering how to replace a transmission, you’re probably in a tight spot.  Replacing the transmission on your car is no easy job, but if yours isn’t working properly, then you may not have much of an option.  Before you go jacking your car up and turning wrenches you may want to consider the cost.  Remember, even if your car doesn’t drive it is still worth something.  You can always advertize it as a mechanics special in your local car listing, donate it one of the many car donation programs like Kidney Cars, or sell it to a junkyard.  Once you add up the cost of all the parts you will need, including a new transmission, and the labor to replace your transmission or the time it will take you to do it, you may be better off cutting your loses and finding a new vehicle.

You may also consider rebuilding your transmission rather than replacing it.  More than likely, most of your transmission is fine and reusable, there are just a few parts that need to be replaced.  It may be more economical to rebuild your transmission and reinstall it rather than installing a new, or used transmission.

If you’re still interested in replacing your transmission, know the procedure will vary significantly whether you are doing it on a front wheel drive car, all-wheel drive vehicle or a truck.  Because of that, our procedure will be very general and only cover the basics involved in any transmission replacement.  With any maintenance item on your vehicle, start by disconnecting the negative battery cable and blocking your vehicle so it cannot roll or move.  In most cases, you will have to significantly raise your vehicle in order to have enough room to remove your transmission from the bottom.  Having approximately twice the height of your transmission will make the job much easier.  A lift is the easiest way to do this, but if you do not have a lift, use extra care in lifting and securing your vehicle.  Jack stands should be placed under frame rails, pinch welds or axles.  Before you crawl under your vehicle, make sure it is absolutely secure.

To minimize the number of times you are up and down, it is smart to do everything you can under the hood before you crawl under.  This can include loosening bolts, unplugging wiring harnesses and moving shift linkages.  In some cases, you may even need to remove interior components like the center console to move shift linkages or gain access to wiring clips and plugs.  The goal of this step is to make sure you remove anything that may be connected to the transmission so it isn’t damaged during removal.

Next, slide underneath your vehicle.  Again check for wiring and connectors that you can remove as well as hoses or pipes that cross under your transmission that you may need to remove so you have room to take the transmission out.  Next, drain the transmission fluid and remove the axles or drive shafts.  If you have a 4 wheel drive vehicle, you may consider removing your transfer case before you remove the transmission, or it may be easier to remove them as a unit and separate them once they are out of the vehicle.  Once you have all the wires, hoses and other equipment removed from the transmission, the fluid drained and the axles or drive shafts removed, you are ready to start removing the transmission.

Start by removing the bolts that attached the bell housing to the engine block.  Some of these may be easier to remove from the top and some of them may require long extensions or universal joints on your sockets to remove them.  Your transmission will be held in place by the alignment dowels and the input shaft so you should be safe to remove all the bolts without the transmission sliding out, but be careful as you remove the last few bolts.

You then need to slide the transmission straight away from the engine in order to not damage the clutch or torque converter.  Your transmission is supported by a cross member or an engine mount so you need to first remove that.  In removing the cross member or mount, make sure you are supporting the weight of the transmission and engine with a jack or stand to keep from damaging the mounts.  You need to support the transmission with a jack with wheels so you can use it to support the weight of the transmission as you slide it straight away from the engine.  Once you can see the entire input shaft or torque converter you can start to lower the transmission and pull it out from under your vehicle.

Installation of your new transmission can go in the opposite order.  Things can be made simpler by labeling components you remove properly and saving and labeling the nuts and bolts you remove so you can put everything back together the right way.

If this explanation sounds long and arduous you’re right.  Knowing how to replace a transmission doesn’t always make the job easier as they are heavy and awkward to handle and require the removal of a lot of equipment.  To make sure you won’t have to replace your transmission anytime soon, make sure you do everything you can to maintain your current transmission.  The best thing you can do is regularly check your transmission fluid to make sure the level is where it needs to be.  The other thing you can do is make sure to change your transmission fluid at the factory recommended intervals.

Old transmission fluid can cause premature wear to your transmission necessitating a replacement, but low transmissions fluid levels are just as bad for your transmission.  Regularly checking your transmission fluid level can help you catch a leak and add fluid before any damage is done.  If you find your transmission fluid level low, add BlueDevil Transmission Sealer along with your new fluid to seal the leak and prevent another low fluid level in your transmission.

You can learn more about BlueDevil Transmission Sealer here: Transmission Sealer

You can purchase BlueDevil Transmission Sealer from any of our partnering local auto parts stores like:

• AutoZone
• Advance Auto Parts
• Bennett Auto Supply
• CarQuest Auto parts
• NAPA Auto Parts
• O’Reilly Auto Parts
• Pep Boys
• Fast Track
• Bumper to Bumper Auto Parts Specialists
• S&E Quick Lube Distributer
• DYK Automotive

 

Pictures provided by:

transmission.jpg – by Bill Wrigley – Licensed By Creative Commons via Wikimedia – Original Link
transmission_removal.jpg – by EMcCutuchan By Creative Commons via Wikimedia – Original Link