Shipped only to Commercial/Business Locations
Due to a current shortage of available core units, we will need your core to build.
This was our first 1000HP transmission offered at PerformaBuilt. We start with only late model cores for our performance line and application based core for our heavy duty line (Heavy Hauler). Each of these units features all the latest upgrades and high quality materials for assembly. Below is the breakdown of the Performance 4L80E build.
The unit is disassembled, each part carefully inspected and clearances are measured to meet our specifications not just the maximum clearance allowed by GM.
The case is carefully inspected, cleaned and re-inspected. Then it is coated with a special heat and oil resistant paint making for a very tough finish and a clean look.
Bushings are replaced and sized as needed to performance specifications.
The intermediate clutch sprag consists of an extreme duty intermediate sprag and roller assembly with specially prepared race and spiral ring, to prevent high RPM snap ring release.
The forward and direct clutch friction plates are replaced with heavy duty performance friction plates. The drums are then modified to accept additional friction plates and the apply area it self is altered to allow use of the entire piston area for apply in the forward drum. “Dished” cushion plates in these units are replaced with the TH400 style plates for additional reliability. These modifications will also result in a much firmer apply-into-gear from neutral/park to reverse/drive. But durability is significantly increased.
For the intermediate, direct and overdrive clutches we use the Raybestos Stage 1 Performance Friction Plates. These frictions exceed anything on the market for “performance street/strip” and “heavy duty” applications and are more than suitable for any application.
The intermediate overrun band is replaced with a heavy duty unit. This is mostly valuable in heavy duty truck applications, since this band is used to hold back when the transmission is manually put into 2nd gear while descending steep grades, etc. It will hold up significantly better to engine braking.
The low sprag is replaced with a heavy duty type and the low/reverse band is replaced with either a performance band, or a heavy duty band for our heavy hauler applications.
The Pump is carefully inspected and reconditioned for maximum durability and pressure. Special modifications are made to increase cooling and planetary lubrication.
Our own PerformaBuilt shift kit is installed in the valve body. This kit is custom set to the type of unit purchased. The heavy duty setup is for maximum hold with minimal “shift shock”, while Performance units are set for a more aggressive race feel, while maintaining a progressive shift that increases in firmness as you add more throttle.”
Each unit comes with a PerformaBuilt warranty according to the terms listed on our warranty page.