What Should Your Garage Do After an Automatic Gearbox Replacement?
Replacing the car’s transmission is not a task that many of us can take on ourselves. In fact, nearly all professional mechanics recommend that you never attempt it, even if you have some degree of experience and/or confidence to do the job yourself. An automatic gearbox is an extremely complex piece of kit, and it’s best left to those with the real knowhow.
So, what’s left for you to do? While you might not be performing the task yourself, it’s still important that you know both what the job entails, and what the follow-up steps are on the part of your mechanic. When you know, you can check, and when you can check, you can avoid things going wrong. Below is our info on what you need to know about what garages need to do during and after an automatic gearbox replacement job.
1. The Replacement Itself
First, let’s be clear on what exactly an automatic gearbox replacement entails. The job can potentially take a few days’ time to finish completely. Below you’ll find a step-by-step rundown of what typically goes on:
Part 1: Removal
Step 1: The first components they remove are the negative battery cable, plastic air intake components (if needed to make space), the transmission fluid dipstick and dipstick tube, as well as any brackets, cables or hoses that are currently fixing the automatic gearbox to the engine.
Step 2: The mechanic will next remove the starter bolts — possibly the whole starter if that’s necessary — and pull the starter from its housing to push it aside. They should use a bungee cord to support it, and not let it just dangle from its wires.
Step 3: The previous step allows access to the transmission housing and where it attaches to the engine. This housing is then removed.
Step 4: Next, the rear wheel is chocked and the front of the vehicle raised up. Transmission fluid is drained into a receptacle.
Step 5: The driveshaft is released from the differential and then removed to be set aside until being restored later.
Step 6: Electrical connectors and hoses are removed, as are transmission oil cooler lines, starter bolts, the torque converter, transmission mount, cross member, exhaust crossover pipe, transmission bell housing bolts are removed.
Step 7: Finally, the torque converter and transmissions are separated
Part 2: Installation
Much of the installation is restoring the steps mentioned above, but there are some key inspection points that the mechanic first undertakes. They first check the surfaces of the transmission housing and the engine for any dirt, grease and other contaminants and first clean it up as needed.
Next, they check the crank pilot hole to ensure that it is also free of any debris or rust. They’ll also make sure any wiring and other electrical components are safely pushed to one side. With great care, the new transmission is positioned and then secured in place by reattaching all of the housings, brackets, belts, hoses and other components that were removed during the first part.
It sounds simple when put in this way, but there are countless things to check while removing and then preparing the new automatic gearbox for installation. It takes a lot of experience and training just to make the process safe, which is why it’s virtually never recommended that gearbox replacement is done as a DIY job.
2. Follow-up Checks
The next thing that you the customer need to know is what a garage mechanic should be doing after the replacement job is complete. When you know these things, you can double check with your mechanic that they have been done if and when it comes time for your own automatic gearbox to be replaced:
Transmission Fluid and Shift Checks
First of all, the mechanic should have put in up to 5.5 or 6 litres of fresh transmission fluid back into the system, depending on how much is typically required for your specific vehicle make, model, year, etc. After this, they should start the engine and then test each of the gears one by one using the shifter. As they cycle through the gears, the car’s brake pedal should be held down.
At the end of the test, the mechanic should then return the shifter back to “Park.” The reason for this test was to allow the new transmission fluid to find its proper level within the system. The mechanic should have checked this after the test by looking at the transmission fluid dipstick.
Checking for Leaks
The next task of the mechanic is to look under the vehicle, inspecting the undercarriage for any signs of leaks. Just about any leak of any fluid on a car is a bad sign, but after a gearbox replacement, the potential for leaks remains. It’s an intricate job and all kinds of things can go wrong. If there are no signs of leaks anywhere on the vehicle, then the mechanic can move on to the next check.
Having put the new transmission fluid through the system and then checked the undercarriage for leaks, the car and its new automatic gearbox need to be tested. The car should be driven enough for the test driver to use all the various gears and make sure that the automatic shifts are happening smoothly and correctly.
While test driving, the mechanic will undoubtedly check for any signs that the new installation has a problem. This could be delayed engagement of a gear, thudding or grinding sounds, slipping and more. These are all the things they check, and therefore should be able to tell you about when you collect the car to take home again.
Know the Work of Your Garage
Not all of us can be good mechanics, no matter how much enthusiasm we have for the area. There are some jobs that are beyond us and we therefore put into the hands of professionals. This doesn’t mean, however, that we shouldn’t know what goes on at the garage as they perform repairs and replacements like these. Arm yourself with knowledge so you’ll always know what questions to ask when the time comes.