Replaces both 6-inch internal cartridge filters and the cover gaskets and O-rings in an Allison 3000 or 4000 series deep-sump transmission.
This kit services the two internal cartridge filters in an Allison 3000 or 4000 Series automatic, the medium- and heavy-duty transmission found in school and transit buses, fire apparatus, refuse and vocational trucks, and diesel pusher motorhomes. It contains two 6-inch filters plus the gaskets and O-rings that seal the filter covers. If your coach or truck is due for its filter interval, came back from a fluid service with a leak at the covers, or is showing high temperatures or shift complaints after a long run on old filters, this is the kit to look at. It is not for the Allison 1000/2000 behind a Duramax pickup, which uses a spin-on filter and a pan filter instead.
The 3000 and 4000 Series carry two filters side by side in the control module sump. The main filter cleans fluid headed to the control main circuit, which feeds the solenoids and valve body that apply each clutch. The lube filter cleans the fluid that returns from the cooler to lubricate bearings, bushings and gear sets. Both are pushed up into bores from underneath and held by bolted covers, so on these units you do not drop a pan to change filters. When the media loads with clutch material and wear debris, main pressure and cooler flow both suffer, and debris that bypasses a loaded filter ends up in the valve body bores.
Sump depth decides filter length. Allison built the 3000/4000 with a 2-inch and a 4-inch sump, and the service filters are different lengths; this kit carries the 6-inch filters for the deeper sump and replaces Allison 29548988, 29558118, 29558329, 29540494, 29545779, 29526898 and 29506337. A 2-inch sump takes the 4-inch filter (29548987) instead. Measure the old filter, or check the part numbers, before you open the box. Cross references are Donaldson P560971, Fleetguard HF28943 and Baldwin PT9415-MPG KIT. Older units built before January 1996 (3000 before S/N 6510069120, 4000 before S/N 6610009730) with filter cover 29507434 also need square-cut seal rings 29501469, which Allison sells separately. Send us the transmission serial number if you want us to check. The other Allison 3000 Series two-filter kit and the rest of our Allison parts are on the Allison parts page.
The TES 668 fluid change and how mixtures affect intervals are covered in our Allison fluid and filter service guide; the fluid rules there apply across the 3000/4000 line as well.
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Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
The 6-inch filters go with the 4-inch deep sump. A 2-inch sump takes the shorter 4-inch filter, part 29548987. Measure the old filter or check its part number before ordering.
No. Allison's procedure says not to drain the fluid if only the filters are being replaced. You will lose roughly 2 quarts at the main filter and 8 at the lube filter, so have fluid ready to top up.
Allison specifies 38-45 lb-ft. Seat the covers by hand first, never pull them up with the bolts, and do not use an impact wrench.
The most common cause is an old O-ring left in the bore so two are stacked, or a pinched seal from drawing the cover up with the bolts. Pull the cover, clean the bore and reinstall with fresh seals.
An Allison-approved TES 668 or TES 295 synthetic fluid. TES 668 is the current recommendation and is backward compatible with earlier approved fluids.
No. The 1000/2000 Series uses a spin-on control main filter and an internal pan filter, which are separate parts.
