ALTO 8L90 Performance Transmission Rebuild Kit & Billet Input Shaft - Level 3 (Added Clutch Capacity)
Instructions are included. However, if you're inexperienced with the 8L90 we recommend that you purchase a Service Manual. We also sell the manual. | FREE UPS Ground to the contiguous United States (lower 48)
In stock items ship within 1-2 business days.
Picture for representation purposes only. Actual contents may vary as we continue to develop our products.
Picture for representation purposes only - actual contents may vary as we continue to develop our product.
Billet Input Shaft is precision machined from 300M alloy steel & heat treated for additional strength & durability. In order to reduce breaking points, this shaft has an increased radius between the sealing rings. PLEASE NOTE: The shaft we provide is complete with sealing rings installed - it is a Drop-In Part. Therefore, you do NOT need to purchase The Sealing Ring Installer or Ring Sizing Tools.
⚠ Important: Multiple Versions Available
The 8L90 transmission uses different input shaft designs depending on model year, application, and torque converter setup. To ensure you receive the correct part, please confirm the following before ordering:
Model Year & Vehicle – The shaft design can vary between early and late model 8L90 units.
Shaft Style – Determine whether you have the early-style or late-style spline configuration.
Torque Converter Compatibility – Match the shaft to your converter hub size and spline count.
How to Verify:
Check your transmission’s build tag or serial number.
Measure your existing input shaft and count splines.
Text us a clear photo of your input shaft and converter hub to 713-895-7019.
💡 Tip: If you’re unsure, our team is happy to help confirm fitment before you order—avoiding downtime and return shipping delays.
(5) CLUTCH PACKS
- C1 1-2-7-8-R
- (4) Clutches
- (3) Steel Plates
- (1) Wave Plate
- (1) Apply Plate
- (1) Backing Plate
This is the latest design OEM clutch pack from GM - it includes the (3) thicker steels to help with heat dissipation and warpage.
- C2 1-2-3-4-5-R
- (3) Clutches
- (2) Steel Plates
- (1) Apply Plate
Stock clutch capacity.
- C3 1-3-5-6-7 CDT Modified Alto Power Pack
- (6) G3® Friction Plates
- (7) Steel Plates (varying thicknesses)
- (1) Backing Plate
Adds 1 additional clutch to either a 4-clutch or 5-clutch drum. G3® friction material is formulated to achieve minimal wear and maximize heat resistance.
- C4 2-3-4-6-8 CDT Modified Alto Power Pack
- (6) G3® Friction Plates
- (7) Steel Plates (varying thicknesses)
- (1) Apply Plate
- (1) Backing Plate
Adds 1 additional friction while retaining the wave plate OR adds 2 additional frictions while omitting the wave plate. G3® friction material is formulated to achieve minimal wear and maximize heat resistance.
- C5 4-5-6-7-8-R CDT Modified Alto Power Pack
- (5) G3® Friction Plates
- (6) Steel Plates (varying thicknesses)
- (1) Backing Plate
- (1) Snap Ring
Adds an additional clutch and steel while retaining the factory wave plate. G3® friction material is formulated to achieve minimal wear and maximize heat resistance.
Overhaul Kit This overhaul kit is engineered utilizing premium materials.
Hi-Per Blue® Piston for C1 (1-2-7-8-R). Manufactured with upgraded High-Performance Blue AEM material for superior thermal and chemical resistance with better fit and performance.
GM Filter
