Pontiac G8 Transmission Problems & Cost | 5L40E | 6L80

The Pontiac G8 was equipped with the 5 speed 5L40E and the 6 speed 6L80 transmission. But they aren’t without their problems though, so let’s look at some of the most common Pontiac G8 transmission problems, look at cost estimates and figure out what you can do about them.

Need a replacement transmission? Get an estimate for replacement transmissions and local installation. Look up your transmission model by vehicle make and model.

What Transmission Do I Have?

Pontiac G8 Transmission Models

Pontiac G8: 5L40E Transmission
Pontiac G8: 6L80 Transmission

Pontiac G8 Transmission Replacement Cost Estimate

Pricing varies by model. To be 100% sure on pricing, have your VIN# handy and use our Get An Estimate feature to look up your transmission by VIN#.

Replacement Pontiac G8 Transmission Prices:

What are the DTC codes related to Pontiac G8 transmission problems?

Pontiac G8 Transmission Recalls

None Found

Pontiac G8 Technical Service Bulletins (TSB)

TSB PIP495F – Flare and/or harsh 2-3 shifts – 6L80 Transmission
2006 – 2009 Cadillac STS-V – 2006 – 2009 Cadillac XLR-V – 2007 – 2009 Cadillac XLR – 2006 – 2009 Chevrolet Corvette – 2008 – 2009 Hummer H2 – 2008 – 2009 Pontiac G8
Problem – Drivers can experience an unusually harsh 2-3 shift or flare. They may also experience an usual delay when shifting from Park, Drive and/or Reverse. The symptoms are more likely to happen in colder climates, however they can still happen at any temperature.
Solution – These 6L80 transmission problems can be caused by a leaking 1-2-3-4 and 3-5-R clutch seal rings. The clutch packs, discs and drums should also be inspected for signs of damage. Many remanufactured 6L80 transmissions come already modified to correct the causes of these problems.

TSB 09-07-30-004J – Slips in Reverse or Third, Delayed Reverse or Drive Engagement, DTC P0776, P2715, P2723, Harsh 2-3 Shifts – 6L80 Transmission | 6L90 Transmission
2006-2009 Cadillac STS-V – 2006-2009 Cadillac XLR – 2006-2009 Cadillac XLR-V – 2007-2008 Cadillac Escalade, Escalade ESV, Escalade EXT – 2006-2009 Chevrolet Corvette – 2007-2008 Chevrolet Silverado – 2008 Chevrolet Suburban – 2007-2008 GMC Sierra – 2007-2008 GMC Sierra Denali – 2007-2008 GMC Yukon Denali – 2007-2008 GMC Yukon XL Denali – 2008 GMC Yukon XL – 2008-2009 HUMMER H2 – 2008-2009 Pontiac G8
Problem – Vehicles equipped with the 6L80 or 6L90 transmission may slip when Reverse is selected or have no/delayed reverse engagement, harsh shifts from 2-3 / 4-5 or slips while in fifth, and slipping acceleration when passing. Possible DTCs include P0776, P2715 or P2723.
Solution – This transmission problem may be caused by a cracked 1-2-3-4 / 3-5-R clutch housing.

Common Pontiac G8 Transmission Problems

Lack of Response
Leaking Fluid
Low Fluid
Burning Smell
Grinding or Shaking
Whining, Clunking or Humming
Refuses to Go Into Gear
Torque Converter Issues
Valve Body Issues
Transmission Noisy in Neutral
Gears Slipping
No 3rd or 4th Gear
No 1st or 2nd Gear
No Reverse
Dragging Clutch
Trouble Codes / Check Engine Light

Can I drive with a transmission problem?

If your Pontiac G8 can still make it up and down the road, you might say “It’s fine, I’ll just drive it until I can get it fixed”. But that is not always a good idea, depending on the symptoms. You see, there are a lot of (very expensive) moving parts inside of a transmission, and if something isn’t right, continuing to drive with a transmission problem could damage something else.

How often does a Pontiac G8 transmission need to be replaced?

The overall lifespan of a Pontiac G8 transmission largely depends on how well it was maintained. Factory design flaws also factor into this equation, along with how/how hard you drive. But on average, we’ve seen the Pontiac G8 transmission last for between 130,000-180,000 miles. A high quality replacement transmission however, can last considerably longer if all of the factory design flaws have been addressed and the vehicle has been maintained.

How are Pontiac G8 transmission issues diagnosed?

It is fairly easy to guesstimate what the root cause of your Pontiac G8 transmission problems might be, but you won’t truly know unless you have the right tools and experience. A good mechanic or transmission repair center will be able to connect your truck to a computer and find out which diagnostic trouble codes (DTC’s) have been stored. Once they know what to look for, they can perform a visual inspection to verify the problem.

How is a Pontiac G8 transmission replaced?

In order to replace your Pontiac G8 transmission, the truck has to be lifted from the ground in order to gain access to all of the parts that will need to be unbolted. Then the transmission can be lowered to the ground (typically with a transmission jack), so the new transmission can be installed. Once it is in place, for the 6L80, the vehicle PCM will have to be reprogrammed / reflashed to accept the new transmission using the latest GM subscription.

Recommendations for Pontiac G8 transmission issues?

To save time and get back on the road faster, have your 17-digit truck VIN# handy and you can get an online quote for a reman Pontiac G8 transmission here, then find a local shop using our Find a Shop guide to install it for you.

How to Solve Pontiac G8 Transmission Problems

Solution A: Buy a Used Pontiac G8 Transmission

The quickest way to fix your transmission problems is to simply buy a used transmission or used transmission. These can be found at most junk yards, and they often come with a 30-90 day warranty. However, there’s no way to determine the actual condition of the internal components, so you could be spending a bunch of money to have the exact same problems. Plus, that warranty only covers the transmission if it’s defective, not the labor costs that you’ll have to pay.

Solution B: Buy a Rebuilt Pontiac G8 Transmission

Another option would be a rebuilt transmission or rebuilt transmission. A local repair shop will remove your transmission, then install a bunch of new parts during the rebuild. The problem here is, the skills and experience of each transmission rebuilder will vary widely from shop to shop, so you could have problems from something that wasn’t adjusted properly. And the 1-2 year warranty might only cover you at certain transmission repair shops, in a specific geographical area.

Solution C: Buy a Remanufactured Pontiac G8 Transmission

Many owners depend on their vehicle to commute and get things done. Their gasoline engines are designed to go 100’s of thousands of miles, so it makes sense to invest in a remanufactured transmission.

Need a replacement transmission? Get an estimate for replacement transmissions and local installation. Look up your transmission model by vehicle make and model.

What Transmission Do I Have?

What Problem Does Your Pontiac G8 Have?

Let us know the year, mileage and problem you’re having as well as any trouble (OBD) codes you’ve found. If you’ve been given a quote or paid for a repair, we’d like to hear about that too!