Transmission Rebuild or Replace?

transmission rebuild

As soon as you notice problems with your car, the most frequently asked question is whether worn parts should be repaired or replaced.

Both options are often quite expensive. When rebuilding the transmission, you need to replace the clutch, seals, gaskets, sealing rings, and bands. All this drives the price of an overhaul to over $1,000.

If you decide to replace it, it means you have a new or newer used transmission, which may work better than the old one.

Things to consider before replacing or repairing

There are a few things to consider when deciding whether to replace or repair your transmission or perhaps even scrap or sell the car. Here are some things you should consider.

1. Frequent breakdowns

If you spend many hours in the garage to replace transmission parts, then it is time to replace them. Long-term repairs are expensive, especially if the problem keeps recurring. Frequent failures are not uncommon with gearboxes that have traveled more than 100,000 miles. If you find that your car spends many hours in the garage instead of on the road, it’s time to replace it.

Most transmission problems can be solved. A repair will cost you several hundred dollars, but if the total cost of the repair exceeds the cost of a new transmission, it’s time to buy a new transmission.

2. Fixing transmission problems

transmission gears

It can be a Herculean task for car owners to know what is wrong with the car’s transmission and you will need to ask your mechanic for help. There are some gearbox repairs that are easy to fix, while others are so expensive that a new transmission is required.

Before you buy a new transmission, you must first diagnose that the transmission actually has problems.

3. Delayed shifting response

The transmission helps to change the gear system. If you are driving your car and suddenly the gears are delayed, you have a problem with the transmission. If you drive a manual car, you will have difficulty shifting the car into the correct gear. With automatic cars, there is a delay in engaging the gear when the car is parked in the car park.

You will notice that the car does not move because the engine is roaring and there is some kind of delay. This is often a worn clutch that can be easily changed. You should rev up the car when changing gears and pay attention to a delayed shift reaction.

4. Clunking or humming sound

First, there are many engine components that can produce this rattling noise. You must eliminate these before you commit yourself to the transmission. It could be that your drive axle bearings or brake pads are worn out. A well-running transmission is often quiet, but the rattling noise is more pronounced in vehicles with manual transmission than in automatic vehicles.

As soon as you hear this humming, have the car checked by a mechanic. Further use of the car will cause more damage.

5. Leaking transmission fluid

The fluid is essential to keep all moving gear parts well lubricated. It also helps to keep the parts clean and reduces heat emission due to friction. You can distinguish the transmission fluid from other car fluids by its red color and sweet smell. If you notice that it has a darker color with a burning odor, you must rinse it out and replace it.

Unlike the engine oil that is consumed by the car, the transmission oil should never get too low. You can detect a leak when you observe the dipstick.

6. Shaking car

If your vehicle components work well, you should enjoy a quiet ride on paved roads without shaking. However, if you hear crunching noises on slippery roads while the car is shaking, there is a problem with your transmission. With manual vehicles, diagnosis is easier.

If the noise occurs when you engage and shift to another gear, the problem is with the clutch. Replacing the clutch is cost-effective, although it can take a day to replace it. With automatic cars, you will notice a shaking of the car when it shifts to the next gear.

7. Refusal to shift gears

There are moments when you engage the gear, but the car doesn’t engage even after the clutch is depressed. There are several possible reasons for this. The first is that the transmission fluid is leaking. If you have bought and installed a fluid with the wrong viscosity, you will have problems engaging the gears.

Secondly, the trip computer system might not be working or sending signals. You may have problems if the sensors are dirty or have problems with the wiring. If everything is fine, try resetting it by removing the battery terminals and allowing the computer to reset itself. Finally, check that the shifter cables are properly adjusted.

8. Check engine light

This is an important light on the dashboard that informs you when the engine of your car is not working as expected. It could mean that many things are not working and the transmission is one of them. You must rule out other possible causes.

The onboard computer detects problems using sensors connected to the transmission and other engine parts. If the transmission has a lot of shocks, the light will come on.


Most transmission problems can be solved if they are not so serious. A defective clutch can be repaired so that leaks can be eliminated. Bearings and gears wear out after extensive use; a mechanic can repair this and get your gearbox back to work. Computer sensors become contaminated with dirt, which causes them to turn the check engine light on.

The purchase of a new transmission costs between $1,300 and $3,400, depending on the vehicle model. You will then have to spend $500 to $800 in labor costs to install a new transmission. However, if you replace a lot of transmission parts, the repairs can be more expensive than buying a new transmission.

Your mechanic can put the cost into perspective and you can then decide which option you want. Older cars often have this problem, and when the gearbox starts to fail, other parts fail as well. In this case you may have to buy a new car.

Written by:

Magnus is the owner and main author of MechanicBase. He has been working as a mechanic for over 10 years, and the majority of them specialized in advanced diagnostics and troubleshooting. He has also been a motorsport (drifting) driver for over 5 years.