A transmission rebuild means removing the transmission, taking it apart, replacing the worn soft parts such as clutches, bands, seals, gaskets and the filter, replacing any damaged hard parts, and reassembling it. The alternative is to replace it with another unit. Which makes sense depends on what failed, how much damage there is, and how long the vehicle will be down.
What a transmission rebuild involves
- Diagnosis: confirm the problem is internal, not fluid level, a sensor, a solenoid or wiring. See transmission solenoid symptoms and transmission slipping: signs and causes.
- Removal: the transmission comes out of the vehicle, along with the torque converter.
- Teardown and inspection: every part is cleaned and checked for wear.
- Replacement parts: a rebuild kit covers friction clutches, steel plates, seals and gaskets; bands, bushings, the pump, planetary gears or shafts are replaced if worn or damaged. Many rebuilders also fit updated valve body parts that address known weaknesses.
- Torque converter: usually replaced or rebuilt too, because a failed transmission can leave debris in it.
- Cooler and lines: flushed or replaced so old debris does not reach the rebuilt unit.
- Reinstall, fill and relearn: fill with the specified fluid, check the level at temperature, and let the computer relearn its shift adapts.
Rebuild vs replacement
| Rebuild your transmission | Install a replacement unit | |
|---|---|---|
| Downtime | The vehicle waits while the unit is rebuilt | Swap as soon as the unit arrives |
| What you get | Your original case and parts, with worn parts replaced | A complete unit, ready to install |
| Hidden damage | Found during teardown, and can add parts and time | Not your concern once the old unit is out |
| Upgrades | Depend on the rebuilder | Choose a version built for your use |
When a rebuild makes sense
- The failure is limited, such as worn clutches in an otherwise healthy unit.
- You have a trusted transmission shop and can wait for the work.
- The transmission is rare or hard to find as a replacement.
When replacement makes sense
- There is major hard-part damage, such as broken gears, a cracked case or a failed pump.
- You need the vehicle back quickly.
- You want a unit built for towing or added power rather than a stock rebuild.
Replacement transmissions we carry
We carry Monster Transmission automatics for Chevy, GMC, Ford and Dodge/Ram vehicles, each supplied with a torque converter, in three versions: RoadReady, a direct replacement for a worn or failed original transmission; StreetMonster, an upgraded unit for daily driving, towing and moderately modified engines; and SportMonster, a performance unit for towing, hard use and modified engines. Find yours by code on our transmissions page or by make: Chevy and GMC, Ford and Dodge and Ram. What transmission do I have? helps you identify your code, and transmission replacement cost explains what to budget for, and how long do transmissions last? covers expected life.
More guides: 4L60E rebuild or replace · used vs rebuilt vs remanufactured · signs of a bad transmission · transmission or torque converter? · how to install a transmission · rebuilt vs used transmission · how long a rebuilt transmission lasts.
Shipping is a flat $80.00 per order to US addresses, with 15-day free returns. Questions? Ask a parts specialist.