Allison 3000 Series Transmission Filter Kit, 2-Filter

This is the two-filter service kit for Allison 3000 and 4000 Series automatics, the transmissions behind medium-duty diesels in shuttle buses, box trucks, dump bodies, fire apparatus and motorhomes. It replaces Allison kit 29558329 and matches the OE filters in fit, form and function. Part number on this kit is BCA1227KT, made and stocked in the USA.

The 3000 and 4000 Series carry two internal filter elements rather than a single pan filter, and both get changed together at every fluid service. Running past the interval starves the pump and drives control pressure down, which shows up as late or slipping shifts, a transmission that heats up under load, and eventually clutch damage that costs far more than a filter kit. On a unit that has been neglected, the filters are also where you read the transmission: metal or friction material in the media tells you what is happening inside before you pull the pan.

The kit includes both filter elements, the gaskets and O-rings needed to seal them, and installation instructions. It also covers the earlier and superseded numbers 29548988, 29540494, 29545779 and 29526898, plus common crossovers 57740XE, P560971, PT9415MPGKIT, 5HA614 and HF28943. Pre-fill the elements with clean fluid before install, seat the seals dry, and set the level hot at idle rather than trusting a cold reading.