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?
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Customer Reviews
Highly recommended. Ray and guz....
Jason Yang
Highly recommended. Ray and guz. Very professional and honest with their work. I drop off my 2018 ford f150 with a 10speed transmission for rebuild and it was nicely done. I got my truck back within a week waiting for parts from ford take the longest. truck drive like new again. Im Very happy. Thank you guys.
Date: May 4, 2023
Website: Google
Took my truck into the...
Kyle Sandahl
Took my truck into the guys and they did a good job and it was pretty quick aswell!
Date: May 3, 2023
Website: Google
One of the best experience...
Adonis Contreras
One of the best experience my wife and I ever had with any mechanic. Coco and her son, were both amazing, they helped us with our immediate issue. Honest and trustworthy, friendly and understanding. God smiled on us that day when our car problem presented and we were lucky to have been at their shop. They turned a problematic day into one of the finest experiences of our lives.
Date: May 2, 2023
Website: Google
A year ago I had...
Gladys OC
A year ago I had a transmission job done there and haven't had any problems, the receptionist was very pleasant, helpful and respectful... best part they charge reasonable price so I guess they have excellent mechanics that really know about transmissions and did a great job, I would recommend this place. Gladys Ortiz. I don't think they do oil change or any other auto mechanical services because I just called and was told they don't do that.
Date: May 2, 2023
Website: Google
They have excellent customer service...
Tracy Beckham
They have excellent customer service at this location. Dan went above and beyond to help me get the best option to replace my transmission. Definitely will use them for service again.
Date: May 1, 2023
Website: Google
"Great service, good analysis of...
Ken Margeson
"Great service, good analysis of the problem and a solution..Definitely felt I was a valued customer . Thanks"
Date: May 1, 2023
Website: Google
Super service done by them...
Niharika Khurana
Super service done by them for my new transmission and excellent after sales service as well
Date: May 1, 2023
Website: Google
They gave excellent service, I’ve...
Jamol Melbourne
They gave excellent service, I’ve done business with Rays shop for a long time. Honest person.
Date: May 1, 2023
Website: Google
Darren was polite and honest...
Glenna Daisey
Darren was polite and honest about the work required. How long it was going to take and my options. I was comfortable through the whole process.
Date: April 30, 2023
Website: Google
Excellent service, extremely nice to...
Mircea Tocitu
Excellent service, extremely nice to talk to, explained everything into detail good repair.
Date: April 30, 2023
Website: Google
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