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The transmission pan gasket seals the pan on the bottom of an automatic transmission, and Route 66 Auto Repair in Upland replaces it when it leaks. Gaskets harden with heat and age, and over-tightened bolts can bend the pan rail. Our ASE-certified technicians fix both problems, not just the gasket, then set the fluid level the way your transmission requires.
How can you tell the pan gasket is leaking?
- Red or brown drips under the middle of the car
- A wet ring around the edge of the transmission pan
- Fluid residue collecting on pan bolt heads
- The fluid level drops slowly between services
- Previous shop work left a gasket sealant squeeze-out
Why do pan gaskets leak?
Heat is the main cause. Inland Empire summers and stop-and-go on the 10 bake the gasket until it shrinks. Bolts also loosen over time. The other cause is the pan itself: a bolt tightened too hard dimples the pan rail, so the new gasket cannot seal. We check the rail with a straightedge and straighten or replace the pan if needed.
Because the pan comes off anyway, this is a good time to replace the filter on transmissions that have one. See transmission filter replacement. We also look at what is in the pan: fine material is normal, but large debris is worth a transmission fluid analysis conversation. If the drip is coming from higher up, the transmission fluid leak repair page explains how we trace it.
Our pan gasket process
Step 1: Confirm the source
We clean the area and confirm the leak is at the pan and not a seal or line above it.
Step 2: Drop and inspect
The pan comes off and the debris in it is checked.
Step 3: Clean and true the pan
Both sealing surfaces are cleaned and the pan rail is checked for flatness.
Step 4: Seal and refill
A new gasket goes on, bolts are torqued in sequence, and fluid is set to spec.
What's included in pan gasket repair
Included on the work order
- 01Leak source confirmation
- 02Pan removal and debris check
- 03Sealing surface cleaning
- 04Pan rail flatness check
- 05New gasket and bolts torqued in sequence
- 06Refill with the specified fluid and level check
Can a pan leak wait?
Need now: call
- A steady drip that lowers the fluid level
- Fluid dripping onto the exhaust
Need later: book
- A damp pan edge with no drips
- Replacing the gasket at the next fluid service
What affects pan gasket pricing?
Most pans are easy to reach, but some sit behind crossmembers or exhaust parts. The fluid lost when the pan drops must be replaced, so fluid type matters too. The written estimate shows each line. AAA members save 10% on parts and labor, up to $75. This job often finishes the same day when the board allows.
After the repair
Check your parking spot for a few days. Some residue can drip for a day or two before it clears. A true leak that returns comes back to the front of our line.
Frequently asked questions
Can I just tighten the pan bolts?
Sometimes a loose bolt is the whole problem. Tightening beyond spec usually makes things worse by bending the pan rail. We check the torque before replacing anything.
Is a pan gasket leak serious?
Usually not right away, but low fluid causes slipping and heat. A steady drip should be fixed soon.
Do you replace the filter at the same time?
If your transmission has a replaceable filter, we recommend it, since the pan is already off. It is a separate line on the estimate.