Ideal for 4×4, heavy-duty and commercial use in GM 4L60 and 4L60/65/70-E units, Sonnax drop-in extra-wide intermediate band (p/n 77700-01K) is the ONLY wide band available that features OEM style high-energy material, according to the company. It’s 15% wider than the OE band, provides 15% more holding capacity, and features a 60% thicker case anchor
Complaint: After overhaul, a 4L70E has a complaint of transmission fluid leaking from the transmission vent. There were no cooler restrictions or filter problems and there was no evidence of cavitation. Cause: The input speed sensor passage and the vent passage in the pump can be connected as shown in figure 1. The rebuild technician
Recover hydraulic control and renew shift operation in GM 4L60/65/70-E transmissions with the new Sonnax drop-in AX code accumulator valve sleeve (p/n 77754-61). Features include: direct replacement sleeve replaces OE sleeves with “AX” code only; renews accumulator action and quells leaks; and the drop-in Zip Valve installs quickly and easily.
The input carrier and the reaction carrier shaft were modified to accommodate the updated bearing.
Find diagnostic and building tips in Transmission Digest’s Tech/Talk quarterly bulletin – October ’20