Drivetrain› Automatic Transmissions and Components

Trans Go Performance

Valve Body Repair Kit for GM 400 / 3L80 Automatic

$29.24

SKU: T09L SK 400

In Stock
In Stock
Ships by Aug 30
Free Shipping over $200
$100 Minimum Order
30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Moderate — 2–4 hours

Overview

The TransGo SK 400 is a valve body repair kit designed for GM 400 and 3L80 automatic transmissions. This kit fits all 400 transmissions from 1965 to the present. It is designed to correct and prevent issues such as soft, late shifts, 3rd clutch burn-up, rough 1-2 shifts, and overly sensitive passing gear.
Show original supplier description
The TransGo SK 400 SHIFT KIT® is a valve body repair kit specifically engineered for GM 400 and 3L80 automatic transmissions. This comprehensive kit is designed to address common transmission issues, including soft and late shifts, premature 3rd clutch burnout, rough 1-2 gear changes, and overly sensitive passing gear engagement. Installation of the SK 400 is designed to be straightforward, with transmission removal being optional. The kit provides a solution to improve the overall drivability and durability of the transmission. It is compatible with all 400 transmissions produced from 1965 onwards. It's important to note that while this kit is highly versatile for the TH400 platform, it does not fit the 4L80E transmission. Additionally, while this kit offers enhanced performance, related products like the 400-3 kit provide manual shift control, and the 400-PRO kit offers a more race-oriented "Gear Command™" system.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

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Specifications

BrandTrans Go Performance
Part NumberT09L SK 400
CategoryDrivetrain

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Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

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