U760E U761E Piston Kit

The U760E U761E Piston Kit is a bonded piston set used during rebuilding of Toyota/Aisin six-speed automatic transmissions in the U760 family. Current transmission-parts catalogs commonly list a four-piece bonded piston kit for U760E and U761E applications, and some suppliers also cross-list the same kit with U760F and TM-60LS transmission families. The pistons form part of the internal clutch apply and balance systems, where hydraulic pressure moves the piston to apply clutch packs and support controlled gear changes.

This product is intended for professional transmission workshops, gearbox rebuilders, distributors and wholesalers. Because piston-kit contents can differ by manufacturer and transmission revision, customers should compare the original piston set, transmission code and kit configuration before ordering.

U760E U761E Piston Kit Components

The U760E U761E Piston Kit is commonly supplied as a four-piece bonded piston package. Specialist catalogs identify one NAK configuration as kit 346008B-NK and list four component references: 346968, 346964, 346984 and 346985. These are transmission-industry reference numbers rather than one single Toyota OE number for the complete kit.

The individual components are associated with different clutch and balance functions. Reference 346964 is commonly described as the C1 forward clutch piston for the 1-2-3-4 clutch circuit. Reference 346968 is associated with the C2 direct clutch section for 4th, 5th and 6th gear operation. Reference 346984 is listed as a C1 balance piston or retainer, while 346985 is a bonded piston used in the C2 direct drum area.

Because aftermarket piston manufacturers may use different part numbering systems, the product should be matched by physical design and transmission application rather than by one supplier number alone.

Bonded Piston Function

A bonded transmission piston combines a rigid piston structure with an integrated sealing surface. During transmission operation, hydraulic pressure acts on the piston and moves it against the appropriate clutch pack or balance circuit. The bonded seal must maintain pressure while allowing smooth movement inside the drum or bore.

Over time, heat, ATF exposure, age and contamination can harden or damage the bonded sealing material. A worn piston can allow hydraulic pressure to leak past the sealing surface, which may affect clutch application and shift quality.

Possible symptoms related to piston or clutch-circuit sealing problems can include slipping, flare between gears, delayed engagement, clutch burn-up or abnormal shift behavior. These symptoms do not automatically prove that the piston kit is the only failed component. Valve-body wear, solenoid faults, damaged friction plates, worn drums, incorrect hydraulic pressure or internal leakage in other areas can produce similar symptoms.

U760E U761E Transmission Rebuild Inspection

During a U760E or U761E rebuild, technicians should inspect the piston sealing surfaces, clutch drums and hydraulic passages carefully. Hardened rubber, torn sealing lips, deformation or visible damage are reasons to replace the affected piston.

Related components should also be checked, including friction plates, steel plates, return springs, bearings, bushings, sealing rings and clutch drums. If the transmission contains heavy metal debris or burnt friction material, the cause of the failure should be corrected before the replacement piston kit is installed.

Clean assembly conditions are important. The piston and drum surfaces should be free from debris and burrs, and suitable transmission assembly lubricant or ATF should be used according to professional rebuilding procedures.

U760E and U761E Application Matching

U760E and U761E belong to the Toyota/Aisin six-speed automatic transmission family. Current aftermarket catalogs list bonded piston kits for both models, with related applications also appearing under U760F and TM-60LS. Exact vehicle fitment varies by market, model year, engine and transmission configuration.

For accurate matching, customers can provide the transmission code, original piston photos, piston dimensions, previous kit reference, vehicle information and required quantity. Physical comparison is particularly useful when a transmission has previously been rebuilt or contains mixed-generation internal parts.

Related U760E U761E Transmission Parts

We supply additional U760E and U761E transmission repair components, including overhaul kits, friction plate kits, steel plate kits, filters, oil seals, gaskets, bearings, valve-body components, planetary parts and transmission oil coolers.

Customers rebuilding a complete transmission can combine the piston kit with related overhaul and hard parts in one order. Sending a purchasing list and clear original-part photos helps us confirm the required specification.

U760E U761E Piston Kit Wholesale Supply

We supply U760E U761E Piston Kit products to professional transmission workshops, rebuilders, distributors and wholesalers worldwide. Current product photos, kit configuration, packing information, availability and wholesale quotations can be provided before ordering.

Contact us with the transmission model, original piston photos and required quantity for product matching and quotation.