Transmission Basics: Understanding the Basic Parts

By Mister Transmission

Before you hand over the keys, brush up on the basics of automatic transmissions so you can understand why your transmission is acting up. Here we’ll cover the basic parts of a transmission, basic transmission problems and how to know if a rebuild is in your future.

What is a Transmission?

The transmission allows you to shift your car from gear to gear, knowing how fast you need to go and how quickly you need to get there. Remarkable stuff.

Parts of a Transmission: 101

While there are many little parts inside, your transmission is essentially made up of 4 key parts of systems:

Bell Housing: This is the cone shaped metal case that you can see when you peek underneath your car. If you have a front-wheel-drive car it’s stuck on the side of the engine under the hood. If your car is rear-wheel-drive, the transmission will be mounted underneath the car behind the engine.

Gears: Even though you’re not shifting them, an automatic transmission has gears. They are broken into main gears and planetary gears. You need all of these to be able to drive.

Fluid: Transmission fluid is very important to an automatic transmission. All of the magic happens in the fluid. Most cars come with red transmission fluid, good to know if you are looking for a leak.

Filter: All of that fluid has to be clean for your car to shift gears at the right time. To keep things fresh, your transmission has a filter to catch any gunk.

Transmission Problems: 101

If your car won’t start or doesn’t run smoothly, these problems are caused by the same faults in your transmission, so whichever your car is doing, the following applies:

Is your fluid level correct?

It’s important to check your transmission fluid at least twice a year. Not only can a low fluid level cause your car to shift poorly, it can eventually lead to transmission damage, and a costly repair. If your car seems to be losing fluid on a regular basis, you may have a leak.

Is your transmission leaking?

Checking for leaks isn’t as difficult as it may seem. The transmission is a closed system, so there are only a few places that can spring a leak. Unless it’s been changed to a non-dyed fluid, your car will have red transmission fluid. Here are a few places to check for leaks:

  • At the filler tube base.
  • At the drain hole underneath the transmission.
  • Between the transmission and the engine.
  • At the selector shaft – the rod that connects your gear shift to the transmission.
  • At the speed sensor mounting point: This will either be your cable screwing into the transmission housing or an electronic sensor bolted to the housing.
  • In the radiator: If your car has a transmission cooler, it’s possible that a leak will cause transmission fluid to leak into the radiator fluid. They don’t mix well, so you’ll see it floating around in there.

Is Your Filter Clogged?

Your transmission’s filter is vital to its performance. If you haven’t replaced your filter in a while, or ever, be sure to do this before you start talking about rebuilds or replacements.

Time for a Rebuild?

When your transmission is worn out, you’ll have to have it rebuilt. For some makes and models of car this is true a little too often. The important thing is checking any other possible causes to your problem before you have it taken apart. If you haven’t replaced your filter yet, start there as this fixes a good percentage of transmission problems. If your filter is in good condition and nothing simple is out of adjustment, it’s likely you’ll need a rebuild. The good news is that at Mister Transmission we offer a rebuild warrantee so you’ll know it will get fixed and stay fixed.

Generally, transmission problems can’t be fixed by the average do-it-yourselfer. There are just too many specialized and expensive tools and pieces of equipment needed. We recommend keeping up with your regular maintenance to keep you out of the shop as much as possible.

Want to know more?
Visit one of our locations

image-reviews image-reviews
Customer Reviews
Super proffesional, problem solved and...
Angus Murray
Super proffesional, problem solved and the bill was as quoted. What else is there!
Date: May 25, 2022
Website: Google
Amazing. Had another place fix...
Rob Jackson
Amazing. Had another place fix my manual transmission and it fell apart in under two weeks. So I went to the pros and that they are. Pulled it apart and had me back together in no time. The only place to get your transmission issues fixed properly and fast. Thanks guys
Date: May 25, 2022
Website: Google
They were great on the...
Sandy Shropshire
They were great on the phone and in person when we needed to get our vehicle towed in. Thanks Chris and Christine
Date: May 25, 2022
Website: Google
Matt and his team are...
LovelaceBreh
Matt and his team are a breathe of fresh air to work with after years of headaches with untrustworthy mechanics & shops. I drive a lifted truck and had my transmission replaced here a few months ago and I've had nothing but great, honest service since my very first phone call with Matt. I usually do all my own maintenance but I felt so confident, I've taken my truck here 4/5 times since (unrelated issues) even sometimes for little things that I could fix myself, just because I trust them to do a thorough job and give me all the details step by step. ALSO, As someone whos had issues with mechanics "Joy Riding" their vehicles before I was ecstatic to see that Matt & his team take extreme care when test driving vehicles (hidden dashcam, so its not because they noticed they were being watched)This is the first ever review I've written for anything, ever. So rest assured the service at Mr. Transmission on Bath Road had to have been pretty awesome for me to leave this.Thanks guys hopefully I don't ever see you again LOL
Date: May 24, 2022
Website: Google
Wonderful staff very friendly, there...
Tristan W
Wonderful staff very friendly, there there for you and not like many shops that’s there staffs attitude when you walk in the door, very helpful and honest! Great place
Date: May 24, 2022
Website: Google
Matt and his team are...
LovelaceBreh
Matt and his team are a breathe of fresh air to work with after years of headaches with untrustworthy mechanics & shops. I drive a lifted truck and had my transmission replaced here a few months ago and I've had nothing but great, honest service since my very first phone call with Matt. I usually do all my own maintenance but I felt so confident, I've taken my truck here 4/5 times since (unrelated issues) even sometimes for little things that I could fix myself, just because I trust them to do a thorough job and give me all the details step by step. ALSO, As someone whos had issues with mechanics "Joy Riding" their vehicles before I was ecstatic to see that Matt & his team take extreme care when test driving vehicles (hidden dashcam, so its not because they noticed they were being watched)This is the first ever review I've written for anything, ever. So rest assured the service at Mr. Transmission on Bath Road had to have been pretty awesome for me to leave this.Thanks guys hopefully I don't ever see you again LOL
Date: May 24, 2022
Website: Google
great work done there
Ljm M
great work done there
Date: May 23, 2022
Website: Google
Dealt with Ken on two...
David Branicky
Dealt with Ken on two seperate occasions and both times he was honest and very helpful.Once I brought my 2003 Dodge Caravan in where I could not drive forward after a hard stop but after a few seconds it would start driving again. So I thought my transmission was starting to give up and would eventually need to be replaced but it turned out to be as simple as my transmission fluid level was low. So once he topped it up I never had that issue again and drove the van another 80k before selling it.
Date: May 22, 2022
Website: Google
I called this shop about...
Michael Cormier
I called this shop about 3 years ago when my 2010 Pontiac G5 needed a new clutch , I spoke with Jason and his price quote was $500.less than any of the other transmission repair shops I had called for quotes . The turnaround was quick and the repair was done for the quoted price and within the time they said it would take , I was extremely pleased ! When my check engine light came on last night and the cars engine power was reduced I called the shop this morning (Friday of a long weekend) and spoke with Jen , they were able to do a diagnostic test and reset , I got my car back within 3 hours when I asked how much they said no charge ! these guys and gals are the best and very trustworthy ! 10 out of 10 stars , Mike in Toronto
Date: May 21, 2022
Website: Google
Want to repair transmission of...
Prajnesh Yajnik
Want to repair transmission of your car, visit this place. A known place for transmission repairs or replaces.
Date: May 21, 2022
Website: Google
Featured Services
Transmission Repair

The evolution of transmissions has made these machines and systems increasingly complex. When transmission repairs are required, determining the cause and cure for what ails can be tricky.

Read More
Transmission Technology

At Mister Transmission we have access to leading-edge diagnostic equipment, enabling us to offer you the fastest and most accurate findings about what’s going on inside your vehicle’s transmission.

Read More
Transmission Maintenance & Service

Just as you have other parts of your car serviced, your transmission needs maintenance to ensure a long life and avoid transmission problems.

Read More
Recent Blogs
Mister Transmission: Your Transmission T...
Everything seems to be computerized these days and automobiles are no different,
Read More
May 18, 2022
3 Common Transmission Repairs
Transmissions are complex pieces of machinery and there’s a lot that can go wrong
Read More
May 11, 2022
When Do You Need Transmission Service?
Transmissions need to be serviced, maintained, and repaired from time to time, but
Read More
May 4, 2022
How Is Transmission Repair Different Fro...
Mister Transmission specializes in servicing transmissions because they’re so
Read More
April 27, 2022
What Are Vehicle Diagnostics?
Discover what vehicle diagnostics are all about, how this practice helps transmission
Read More
April 7, 2022
What Are Some Common Automatic Transmiss...
If you drive a vehicle with an automatic transmission, what are some common automatic
Read More
March 31, 2022
CVTs Vs. Automatic Transmissions
Looking at buying or leasing a vehicle and want to know if you should opt for one
Read More
March 28, 2022
What Is Transmission Oil And Do You Need...
You’ve probably heard of a transmission fluid change, and you’ve probably heard
Read More
March 24, 2022
What Causes Transmission Slipping?
Has your transmission been slipping? It’s important to get it looked at right away.
Read More
February 22, 2022
When Is A Transmission Rebuild Necessary...
If you can avoid ever having to rebuild your transmission, you’ll be better off for
Read More
February 15, 2022