We added this special section for the GM LS4 vehicles. This page shares the common problems that these vehicles often experience from minor nuisances to complete failures.

Our 4T65E-HPS1 / Base High Performance Street/Strip model will work well in a wide range of power levels from stock to roughly the 280-300whp level which is getting into the low 13 / high 12 second quarter mile mark.

2005-up GM LS4 V8 and 4T65-E HD FWD *Want to see the step-by-step swap progress putting this engine/transmission into a Fiero? Click here!* or you can check out the finished swap here . Engine Specs. Displacement: 5.3L / 325 cu in. Bore: 96mm / 3.78in

Of course the most widely aftermarket supported transmission of the three types is the 4T65-E due to the 3800/LS4 marketplace. Finding upgrades specific to the 440-T4/4T60 and 4T60-E has proven to be more difficult.

As all of you know, the 4T65E transmissions are notorious for dying in our cars, especially behind the 300+ horsepower 5.3L LS4 V8 (why in the world GM decided to put this transmission behind this motor is absolutely beyond me).

Our standard rebuild comes with all new clutches, all new electronics and solenoids, MMS shift kit, hardened 4th clutch shaft, and valvebody shift improver kit - making the 4t65eHD perform better and more relaible than even a brand new factory unit.

The stock 4t65eHD is a strong transmission in stock form, but has its limitations and flaws. Our standard rebuild comes with all new clutches, all new electronics and solenoids, MMS shift kit, hardened 4th clutch shaft, and valvebody shift improver kit - making the 4t65eHD perform better and more relaible than even a brand new factory unit.

The 4T65E-HD (code MN7) is a heavy duty version of the 4T65-E used with more powerful engines such as the LS4 V8 and L67/L32 supercharged V6. Free Converter and 3Yr Warranty Warranty.

The 4T65E-HD transmission is the high performance version of the standard 4T65E. It was capable of going behind the LS4 V8, which put down 300+ horsepower at the rear wheels. This makes it far and away the most desirable of the 65E family. Here are …

Sep 13, 2005 · We can now look to repairs such as the Sonnax boost valve & sleeve kit, 84754-30K, and the TCC regulated apply valve, 84754-34K, to correct the hydraulic concerns that lead to this damage. Further, we can add the new Sonnax relief valve, 84757-01K, to ensure the PCM cannot elevate apply pressure beyond the material strength of the converter piston.