I’m getting ready to change my transmission fluid. What should I look for?

The basic inspection should include the following:

  • Ensure transmission mounting bolts are tight and the mounts aren’t worn or damaged
  • Check the fluid level and make sure the fluid isn’t burnt
  • Wires and electrical connections should not be dirty, loose or frayed
  • Make sure the drive shaft is in phase and there is no damage
  • Check U-Joints for wear
  • All fittings should be greased
UTXperts Meeting

We have more than 250 combined years of technical expertise.

These are some helpful tips from our expert technicians:

Checking Transmission Fluid

Flush Cooler Line

When installing a remanufactured Allison Transmission, the cooler and cooler lines must be thoroughly flushed to prevent contamination of the system.

Checking Transmission Fluid


When you replace your transmission, remember to update your TCM.

Checking Transmission Fluid

Filter Changing

When servicing 1K/2K transmission, and replacing the spin-on filter, it is important to collect the magnet off the old filter. Clean the magnet and put it on the new filter.

Checking Transmission Fluid

Vehicle Towing

If you're having your vehicle towed, and it has an Allison Transmission, it is important to disconnect outputs (drive shafts).

Checking Transmission Fluid

Anti-Lock Brake System

If the ABS light is on, it may be causing damage to your transmission. The retarder will not work nor will the lock up or the converter.

Checking Transmission Fluid

Shifting Into Reverse

It's important to bring your vehicle to a complete stop before shifting between drive and reverse. If repeated over time, there’s a chance the ongoing stress can cause the transmission case to crack.


We have over 40 years of experience and a large selection of remanufactured Allison Transmissions.