According to the technical service bulletin PI4075, transmission overheating is common in the 2010 – 2012 Buick LaCrosse equipped with the 6T70 transmission or the 6T75 transmission.
What Transmission Do I Have?
This technical service bulletin was written because General Motors was getting a lot of complaints that the 6T70/6T75 transmission kept overheating in the Buick LaCrosse. Drivers would get a warning message in the driver information center on the dash (DIC, if so equipped) that read “transmission hot – idle engine “. This error message was usually accompanied by the diagnostic trouble codes P0218 or P0634.
The purpose of this TSB was to help technicians determine the cause of the transmission overtemperature situation. One of the first things GM told them to do was ask owners how they were last driving the vehicle. How fast were they going, what type of roads were they on, were they using cruise control, were they towing a trailer, how far did they drive etc. In some cases, the answer to these questions could determine why the transmission overheated.
If the questions did not provide a reason for the transmission to overheat, the technicians were instructed to connect a scan tool and monitor various vehicle systems and sensors (like the transmission fluid temperature sensor/TFT, engine coolant temperature/ECT and transmission control module/TCM) while they took the vehicle for a test drive. The data collected here should help them determine whether the overheating was engine or transmission related.
GM determined that the most common causes of 6T70/6T75 transmission overheating are as follows (this is a pretty obvious list):
1. Transmission overfilled
Adding too much transmission fluid can actually cause the gearbox to overheat. Because the excess fluid is foaming, the ATF will not be able to lubricate or cool all of the moving parts. Plus, adding too much transmission fluid can increase the internal pressure, which will not only overheat the transmission. But damage seals and other components as well.
2. Issues with the transmission fluid
Dirty or old transmission fluid will not be able to cool the moving parts properly, which can lead to an overtemperature situation.
3. Restrictions in the transmission cooler circuit
The transmission cooler is obviously very important to keeping the ATF at a normal operating temperature. So any kinks in the lines, or restrictions can cause the transmission cooler not to function properly, which will result in an overheated transmission.
4. Mechanical problems
It’s advisable to check for proper shifting functionality, and look for any DTC’s that may indicate mechanical failures for the transmission. Any of these can overheat the transmission.
The 2010 – 2012 Buick LaCrosse is actually very nice vehicle, that is a let down by its transmission. So if you want to solve all of your transmission problems at once, you should consider getting a remanufactured 6T70 transmission or remanufactured 6T75 transmission from a company like Street Smart Transmission. They completely reengineer these gearboxes to correct for all the (many) factory design flaws. Then they back it by a 3-year/unlimited mile nationwide warranty that you can actually transfer should you decide to sell or give the vehicle away. To learn more information about this option, click here.
How much is it going to cost to fix my transmission?
Unfortunately, the problem described here will require the removal and disassembly/partial disassembly of your transmission. Given the labor time involved to remove the transmission from the vehicle (this is not a simple task), most repair shops will recommend that you go ahead and rebuild the entire transmission while it’s out. Since they already have to tear it down, it sort of makes sense to spend the extra money to do that. After all, you should get a lot more mileage out of your transmission once it’s rebuilt. And since they’ve already got the transmission apart, might as well, right? Well let’s take a closer look and find out.
Why a remanufactured transmission might be a good option
While you might not be able to buy a brand-new transmission for your particular vehicle, a remanufactured transmission is a terrific alternative. They’re completely reengineered from the ground up and put together on a factory assembly line. They often contain a lot of upgrades over their stock form, which means that many of the design flaws that result in premature failure of components, can be eliminated. This can give a reman transmission a much longer service life than it originally had.
Remanufactured transmission companies like Street Smart Transmission put each of their reman transmissions through a rigorous build process that ensures a quality product every time. It begins with nearly 100 trained technicians that specialize in different aspects of the build process.
Once the build is complete and it passes the final quality control inspection, the newly remanufactured transmission is sent to the dyno room, where it’s tested on a special dyno machine using a proprietary software program called C.A.R.S. (Computer Aided Real-world Simulation). This cycles the transmission through a number of real-world driving situations, to ensure that it performs according to the factory specs. It also helps to break in all of the friction components, that way it’s completely tuned and ready to go once it’s installed.
Warranty – One of the benefits of buying a remanufactured transmission vs. a rebuilt transmission is the warranty. Street Smart Transmission for example, covers all of their reman transmissions with a 3 Year/Unlimited Mileage Nationwide Warranty (there is a mileage restriction for commercial vehicles). This covers parts and labor for transmission repairs performed by any licensed repair shop in the country. It’s also completely transferable if you ever decide to sell the vehicle. Compared to a mechanics warranty on a transmission rebuild, a remanufactured transmission warranty offers superior financial protection.
What Transmission Do I Have?
So is a remanufactured transmission worth it?
If you plan to keep your vehicle for as long as possible, then getting a rebuilt transmission is certainly a viable option. However, a remanufactured transmission is actually a much better alternative in the long run. You’re getting as close to a brand-new transmission as possible. Companies like Street Smart Transmission also modify the transmission to correct all of the factory design flaws, which allows you to get a much longer service life from the transmission. So in terms of value for the money, a reman transmission might be the better way to go. To learn more about the remanufactured transmission for your vehicle, click here.
