You likely had one of two reactions when you read "4L60E." It was either a slight shrug as you vaguely remembered that you had a 4L60E in your reliable, daily-driven V6 Firebird with 150,000 miles, or it was seething GM-aimed anger as you had flashbacks to your '96 Impala SS's 4L60E with an inability to shift to third. The internet is filled with forums, threads, and videos complaining that the 4L60E is a weak, problematic, pale shadow of the burlier 4L80E, or is a perfectly fine, serviceable transmission
that only experiences problems when people forget to change their transmission fluid or put too much power through it.
There are areas where the detractors and the supporters have to begrudgingly shake hands and mutter, "Good point," though. 4L60E haters will note that the transmission has some common issues, and they can be crippling. 3-4 clutch packs can burn out prematurely, the drive shell can break, and solenoid issues can affect shifting. 4L60E apologists will retort that most 4L60E issues can be solved by proper maintenance and never towing in overdrive.
Now, one major issue with the 4L60E's reputation could be its 360 lb-ft torque rating. That's not so much of a problem in and of itself, but this transmission is in plenty of GM products with LT1 and LS1 V8s, which can make around 330 lb-ft of torque and 350 lb-ft of torque, respectively. So, putting a transmission with a torque capacity at or barely above the engine's peak torque in a performance vehicle may be asking for trouble. It's true, the best Corvette is a cheap Corvette, but a Corvette that only shifts to first gear because of a faulty 4L60E will get more cheap in a hurry.
Read more: These Are The Worst Transmission Recalls Of The Last 5 Years
What The Forking Family Tree Of GM Transmissions Is Going On Here
The 4L60E is a direct descendant of the 700R4 and part of the Turbo-Hydromatic branch, which is based on a 1920s design that essentially kicked off the automatic-transmission revolution. Well, the 4L60E essentially is a 700R4, just with electronic controls instead of mechanical controls for changing gears. Yes, there's a 4L60 without the E, and it is a 700R4 that went to the courthouse and filled out a Petition for Name Change.
The 4L60E first appeared in trucks, SUVs, and vans in 1993 and in passenger cars in 1994. The 700R4/4L60/4L60E was the final goodnight kiss to the long-serving TH350 (1969-1984), which went to a farm, where it will be very happy. As great as the TH350 was, it didn't have a fuel-efficiency boosting overdrive or a heat-reducing lock-up torque converter. Here's the rub. As far as we can tell, GM never put the TH350 behind big blocks or high-powered small blocks that stretched its torque limit of 350 lb-ft. If you wanted, say, a 1971 Camaro with an LT-1 or 402 (the real displacement of the "396" in the '70s) and an automatic, you had to check RPO M40 for the TH400, which could take up to 450 lb-ft.
If you ordered an L48 350, then you could get the M38 (TH350). That '71 L48 had a gross torque rating of 360 lb-ft, but by 1972, GM reported the SAE net figure, which was a more realistic 300 lb-ft, well within the capacity of the TH350. Basically, the TH350 generally didn't have to withstand the punishment of timespace folding, torque-laden V8s. But the 4L60E endured the trauma of V8s that pushed it to the brink of its capacity. Can you blame the transmission for that?
Where The 4L60E Will Give You Headaches
Okay, enough devil's advocate for the 4L60E. Transmission Bench has a fantastic YouTube video that discusses the transmission's most common issues and their symptoms. Can't shift to third gear? It's likely the 3-4 clutch pack is burned up because the piston's rubber seals have gone bad. Is first gear the only one that engages? You probably have a broken drive shell. Does it shift harshly from first to second gear? The TCC regulator valve is likely worn out. Another frequent issue with 4L60Es is that their solenoids go bad. When this happens, shifts can become harsh or erratic.
As for other members of the four-speed auto family, there's the 4L65E, which is what the 4L60E morphed into in 2001. GM upgraded the four-pinion carrier to a five-pinion version, improving the torque capacity. In trucks, the rating was 380 lb-ft, and in cars such as the 2005 Corvette, the torque rating was 400 lb-ft. The 4L70E is largely a 4L65E with a pump-mounted speed sensor and an upgraded torque capacity of 430 lb-ft, as per a 2005 New Product Announcement from GM. That transmission was put into vehicles such as the Chevy Trailblazer SS (400 lb-ft of torque) and Saab 9-7X Aero (a Trailblazer SS with plastic surgery and 395 lb-ft of torque).
The 4L80E is the brawny big sibling that can handle 440 lb-ft of torque and gives wedgies to the 4L60E. Unfortunately for torquey performance car fanatics, GM only put the 4L80E in vans, trucks, and the Hummer H1. So if you want to drop $12,500 on a 1996 Chevy Impala SS and upgrade it to a 383 like Callaway did in the '90s, ripping out the 4L60E and swapping in a 4L80E is tough but doable.
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