Your cart is empty
Browse our catalog to find the parts you need.
These images are illustrative and may not match the product exactly. Always verify by part number — or confirm instantly with the assistant using a photo or VIN.

Shell · Tools & Supplies
550062008
In stock · ships from Knoxville
Shell Spirax S6 ATF A668 is a fully synthetic heavy-duty automatic transmission fluid.
Confirm the part fits before you buy. Applications and interchange numbers are researched and audited per part.
Verified fitment for 2 applications
Add your truck to see whether it's one of them
All confirmed applications for this part number.
Other applications
Other applications
This fluid is only for transmissions specifying Allison TES-668. It is not a substitute for transmissions requiring TES-295 or other Allison fluid specifications.
Part data verified against 5 catalog sources
Numbers this part supersedes or interchanges with. Showing 2 of 2.
Different year, make, or config? Get a confirmation against your truck in under a minute.
It is specifically designed for automatic transmissions that require Allison TES-668 fluid, commonly found in heavy-duty trucks, buses, and commercial vehicles. The fluid provides extended drain intervals, excellent wear protection, and reliable performance even under severe operating conditions. You replace or top off your transmission fluid with this product during scheduled maintenance or when a fluid change is due to ensure long transmission life and smooth shifting.
Part Number: 550062008
SHELL SPIRAX S6 ATF A668 (GALLON)
Unit: ea
Dealer: KP Services Crossville
Compatibility, alternatives, and more