If you’re building a performance car, there are a number of areas you need to focus on to make sure all of your upgrades are in sync with each other when it comes time to push the limits of their individual capabilities. For example, if you are upgrading your suspension, the wheels and tires had better be able to handle the new g-forces the car will exhibit in the corners. Planning on adding a supercharger, turbo system, or just upping the ante in cubic inches? You’d better hope that the transmission is up to handling the task. We’re here to tell you that PerformaBuilt Transmissions has one goal in mind: to engineer and build the toughest transmission on the planet, and they’ve proved so not only with their updated designs but also through their pledge of quality, performance, and unparalleled customer service. All of their transmissions are dyno-tested at their production facility and delivered to your door ready to install with a rock-solid warranty with no exceptions for racing or mileage.
On a recent visit, the team was preparing one of their Level 3 Invincible 4L60E units, which is one of their strongest models designed for extreme performance. Packed with upgrades, it features a bevy of modifications making it capable of handling up to 800 rwhp (rear-wheel horsepower), which is far more than the capabilities of a stock 4L60E, which is around 300 hp.
Each unit is methodically re-engineered to overcome many of the inherent factory weaknesses by adding strength and durability. Some of the issues addressed include boosting line pressure from an OEM level of between 140-150 psi to 220 psi, and keeping the unit balanced to avoid “shift shock” (banging shifts) by tightening down clearances; this results in firm, quick shifts as driver input becomes more aggressive. From front to rear, upgrades include a BorgWarner 29-element dual-cage sprag assembly, Sonnax Smart Shell to eliminate the stripping of splines and breakage, a set of Raybestos carbon composite performance clutches with new Raybestos steels, and two Sonnax Super Hold billet servos for Second and Fourth gears for maximum hold to name but a few. Follow along and check out just what it takes to bring a stock 4L60E to the highest level of performance. CHP
1. With all the high-performance parts laid out on the assembly bench, you get an idea of just what it takes to bring your 4L60E to the next level.
2. Once the transmission core has been thoroughly cleaned, inspected, and painted the build gets started with the installation of the rear ring gear.
3. The original four-pinion rear planetary in the 4L60E (right) is replaced with an OEM five-pinion rear planetary (left), which is considerably stronger. Here you can see the thickness and strength differences between the two.
4. The OEM five-pinion planetary, with a grooved sun gear for improved lubrication, is then set in place. The sun gear is a critical part, which after inspection gets four slots machined into its bottom face. This improves lubrication to the rear planetary gear assembly by allowing the oil to escape from between the bearing and the gear it rests against, protecting the area from failure due to a lack of proper lubrication.
5. This is followed by the low-reverse clutches and a heavy-duty, low-roller assembly.
6. Next, the OEM sun shell is updated with a Sonnax Smart Shell, which is cryogenically hardened and balanced. It corrects a historically weak point of stripping splines and breakage in the transmission with extra strength engineered into the unit as well as being balanced to eliminate any potential for vibration.
7. The front ring gear and reaction tube are then loaded into place.
8. Replacing the original four-pinion front planetary set, a new OEM five-pinion unit is prepared for installation.
9. Here you can see the new OEM five-pinion planetary now in place.
10. Another problematic OEM area pertains to the input drum that houses the 3-4 clutches that get damaged under abuse. They add a reinforcement collar along with eight Raybestos carbon composite performance clutches with new Raybestos steels for better drum clearance combined with boosted pressure for quicker and more efficient shifts with more hold once the clutches are engaged.
11. A billet steel collar (pictured) is pressed into place to reinforce the weak point where the aluminum drum typically cracks around the steel input shaft.
12. Here you can see the new collar pressed into place. It will effectively take the stress off the aluminum drum and in effect allows the aluminum to act as a bushing instead of a structural component.
13. Here you can see the layout of parts awaiting assembly for the 3-4 clutches.
14. In building the improved unit, the next performance part installed is a Sonnax input drum reinforcement kit.
15. Next, the Sonnax billet overrun piston from the input drum reinforcement kit is set in place.
16. This is followed by the clutch return springs and overrun clutches being carefully lowered into place.
17. Another upgrade is the installation of a BorgWarner 32-element dual cage input sprag, which is the strongest available on the market today.
18. The 3-4 clutch set is then updated with eight Raybestos carbon composite performance clutches with new Raybestos steels allowing for high-impact durability, heat resistance, and super hold on the 2-3 shift.
19. The drum is then completed with new “sized” Teflon rings.
20. Here you can see the new reverse-input drum and all new clutches to which an ultra-wide carbon composite 2-4 performance band with reinforced pin area to prevent tear-through will be added. This band will be able to take the major abuse and heat. The piston will also receive new inner and outer lip seals.
21. The reverse-input drum is then mounted to the input drum.
22. The entire assembly is then loaded into the transmission case.
23. The new ultra-wide carbon composite band is fitted around the new drum. Considerably wider than the OEM unit, and when combined with the increased pressure and new flat drum surface to clamp onto, it results in a substantial increase in holding power.
24. The two Sonnax Super Hold billet servos for Second and Fourth gears are pictured here awaiting assembly. A huge improvement over original OEM servos, they increase the holding power of the band by roughly 50 percent.
25. Once the unit is assembled, it is installed into the transmission case as the band clearance is set.
26. A 13-vane pump with hardened rings is assembled with a full-time lubrication modification, which assures maximum planetary life and cooling. The max line is set at approximately 220 psi.
27. The valvebody is then installed complete with a new wiring harness and solenoids. Proprietary modifications are made to the valvebody for enhanced performance and longevity. Finally, a deep OEM-style pan and performance filter are installed to complete the build.
28. Here’s the completed PerformaBuilt 4L60E Level 3 Invincible transmission ready for installation once it arrives to your doorstep with everything you’ll need to get the job done, backed up by a bulletproof warranty.