Experienced GM 4L80E specialists since 1987. Free computer diagnostic, lifetime warranty on rebuilds.
The 4L80E is GM's heavy-duty 4-speed automatic — the big brother to the 4L60E. Built for trucks and vans that tow and haul, it's significantly stronger. We rebuild these regularly for contractors, fleet operators, and truck owners who put real miles on their HD trucks. Common issues: front pump, direct clutch drum, and TCC solenoid.
| Speeds | 4 |
| Type | Automatic |
| Fluid | Dexron VI |
| Fluid Capacity | 13.5 qts total |
| Max Torque | 680 Nm |
| Weight | ~255 lbs |
High-torque use cracks the forward clutch drum, especially in trucks used for heavy towing. The drum is a known weak point in trucks over 200k miles.
Symptoms: No forward gears, clunk on engagement, metal in pan
Pump wear leads to low line pressure and TCC slip. More common in high-mileage units.
Symptoms: Slip under load, whine at idle, P0218 (over temp)
The TCC solenoid controls converter lockup. Failure causes shudder or converter that won't unlock, leading to engine stall at stops.
Symptoms: Shudder at cruise, stall when braking, P0741/P0742
The direct clutch handles 3rd gear. Worn packs cause 3rd gear slip, especially under load.
Symptoms: Slip in 3rd gear, burning smell, P0756
"Honest diagnosis, fair price, and the repair was done right. Chicago Transmission has been my go-to for years. Wouldn't trust anyone else with my car."
"The free diagnostic alone was worth the trip. They found the problem fast, gave me a written estimate, and completed the work on time. Exceptional service."
"Family owned and it shows. They treated my car like it was their own. The lifetime warranty on my rebuild gives me total peace of mind. Highly recommend."
Yes. The 4L80E has a higher torque rating, a larger case, and more clutch plates. It's in a different league for towing and hauling.
Yes, it's a popular upgrade for trucks that tow heavily. We can advise on the swap — it requires a crossmember, driveshaft, and PCM tune.
3–4 days. Slightly more complex than the 4L60E due to size.
Usually the TCC solenoid or a worn converter clutch. A fluid change alone won't fix it if the solenoid has failed.
Yes. Express vans with the 4L80E are a regular job for us — same transmission, just different access.
Bring it to Chicago's most experienced GM 4L80E shop. Free diagnostic, written estimate, no obligation.
