Remanufactured GMC G3500 Transmissions
- Learn about common GMC G3500 transmission problems
- Everything you need to know when shopping for a GMC G3500 transmission for sale
- How and when to buy a remanufactured GMC G3500 transmission
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Remanufactured GMC G3500 Transmissions
The GMC van/box truck is a staple of commercial vehicles on the American roads. They are sturdy and can handle lots of weight/abuse. However, transmission problems with the 4L80E, 6L90 or Allison 1000 can bring the work to a screeching stop. So let’s find out if installing a remanufactured GMC G3500 transmission can help you get more work done.
Common GMC G3500 4L80 Transmission Problems
Since this was an early electronically controlled transmission, many shift problems/Check Engine Lights can be attributed to a failed input/output speed sensor, or throttle position sensor.
Slipping Between Gears/Failure to Shift
The 4L80E uses a total of 8 solenoids to actuate gear changes, and activate the lockup torque converter. These little plungers are used to control the ATF fluid pressure, and they’re activated by an electric charge that passes through a coil of wire that’s wrapped around the plunger mechanism. If excessive vibrations or an electrical surge causes the solenoid to short out, you’ll start to experience serious problems.
The primary function of automatic transmission fluid is to remove heat from the moving parts inside. If you’re towing/hauling a heavy load and the radiator cooler can’t properly cool the ATF, the transmission will overheat, causing significant damage to the valve body, seals, clutches, bands, and other parts.
Common GMC G3500 6L90 Transmission Problems
Reverse Fails to Engage
If you’ve selected Reverse and your vehicle still won’t move, then it’s possible the park prawl (the metal piece that stops your vehicle from rolling), or one of the clutches has become damaged.
Slipping Between Gears
If you experience slipping in reverse, or between 2-3, then it’s very likely that the 1-2-3-3/5-R drum has developed a crack, which will require an entirely new drum and bearing.
Slipping in First Gear
If you have difficulty getting your vehicle to move from a dead stop, then it’s possible that one of the solenoids is stuck in the ‘off’ position, or there’s a problem inside of the valve body.
Common GMC G3500 Allison 1000 Transmission Problems
The Allison 1000 works by the concept of adaptive learning. By comparing the average shift time against preprogrammed ideal benchmarks, the transmission can make shifting more efficient. However, rapid changes in speed or sporadic acceleration/deceleration prevent this process from occurring and the gear and valve assemblies cannot adapt to fluid pressure increases.
Another key problem can be an improperly lubricated C3 clutch. The way the transmission is set up, this clutch does not get any fluid unless it’s done directly. It reduces performance due to wear on the clutch pad and can lead to failure.
Five-speed Allison 1000 transmissions have problems with the C1 and C2 clutches. The pistons that cause these clutches to engage were designed slightly off center, leading to a lack of even pressure and in turn to uneven wear and early failure of the clutch plates.
How to Solve GMC G3500 Transmission Problems
Solution A: Buy a Used GMC G3500 Transmission
Going to the local junkyard and picking up a used GMC G3500 transmission might seem like the cheapest and fastest option. But you need to consider the fact that you don’t know what the actual shape of the internal components are. It could very well be on the verge of transmission problems of its own, which would leave you in the exact same predicament that you’re in now. And that 30 – 90 day junkyard warranty probably won’t cover labor charges to install the replacement transmission if something goes wrong.
Solution B: Buy a Rebuilt GMC G3500 Transmission
Getting a rebuilt GMC G3500 transmission would probably seem like a better idea. However, a lot of mechanics and transmission shops will only rebuild your GMC G3500 transmission back to its original factory specifications. Which means that all of those factory design flaws are still going to be in–play. And that rebuilt transmission warranty might only be good at certain shops, which could do you no good if you have transmission problems while you’re traveling.
Solution C: Buy a Remanufactured GMC G3500 Transmission
If you want to get the most service life out of your little luxury SUV as possible, then you really should consider a remanufactured GMC G3500 transmission from Street Smart Transmission. Each one is completely disassembled and re-remanufactured, so nothing is left to chance. They’re also modified to correct the factory design flaws, which will greatly extend the service life. Plus, you get a 3-Year/Unlimited Mile Nationwide Warranty. This will cover parts and labor charges at any licensed repair shop in the Continental United States, giving you a lot more flexibility and coverage.