How to Extend the Life of the 4T80 Transmission in Your Buick Lucerne

Posted by on Tuesday, July 29th, 2014

The 4T80 is a four-speed automatic transmission designed and built by General Motors. It is based on the older TH125 automatic transmission. The T480 was designed to be used exclusively with cars that incorporated V8 engines and used a front-wheel drive design. All engines used with this transmission were of the Cadillac Northstar family. It is a fairly heavy-duty transmission and was used in cars weighing as much as 8000 lbs. This transmission comes equipped with a 2.96:1 ratio first gear and a 0.68:1 overdrive gear.

The 4T80 first went into production back in 1994 and was in continuous use up through the end of the 2011 model year. The 4T80 automatic transmission could be found in many General Motor vehicles, including the Cadillac Deville, the Eldorado, the Seville, and DTS. In addition, it could be found in the Oldsmobile Aurora, the Pontiac Bonneville GXP and the Buick Lucerne.

The Buick Lucerne (Wiki)

The Buick Lucerne was available with the optional 4T80 automatic transmission.

The Buick Lucerne is an upscale, full-size sedan. When in production, it was Buick’s flagship vehicle. It was built to replace both the Buick Park Avenue and the Buick LeSabre. The Lucerne was built on the GM “G” platform and shares many parts in common with the Cadillac DTS. It was available with three engines: 3.8 liter and 3.9 liter V6 engines, and a more powerful 4.6 liter Northstar V8 engine. The V6 versions of the car used the lighter duty 4T65 transmission. The Lucerne was available in a number of different trim levels, including the Special Edition and the Super. The Lucerne was discontinued for the 2012 model year and was replaced as Buick’s flagship vehicle by the LaCrosse.

Buying a new car is a major expense these days. Every year the price of a new car goes up faster than inflation, putting it out of reach for more and more buyers. It is therefore recommended that you do everything you can to prolong the life of your Buick Lucerne. Let’s look at what you can do to extend the life of the 4T80 in your Lucerne.

Our number one tip? Be sure to get the transmission serviced often. A good transmission service should include the following:

  1. Completely drain and replace the old transmission fluid. Don’t forget that the torque converter can hold up to 2 quarts of fluid and will have to be drained separately.
  2. Have the bands adjusted. Unlike the clutch packs found in your 4T80 transmission, the bands do not self-adjust. If left unchecked, over time they will lose their tolerances and slip. Once this happens, the death of your transmission is just around the corner.
  3. Check the transmission’s operating line pressure. It should be tested in all gears while the vehicle is being driven. Low line pressure can cause all sorts of catastrophic transmission failures.

I also recommend that you replace the factory organic, oil-based transmission fluid with a good quality synthetic fluid. Synthetic fluids have much better wear characteristics and won’t break down as easily under extreme temperatures, both cold and hot.

Sooner or later, due to high mileage or abuse, you will be faced with the decision to replace the 4T80 transmission in your Buick Lucerne. We highly recommend doing so with a re-manufactured transmission over one that was simply rebuilt. A re-manufactured transmission will include major internal modifications and upgrades designed to make it both stronger and more durable. To learn more, contact ETE Reman today!

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