Allison Transmission Filter Oil Change B400R & B500R

Allison Transmission Filter Change B400R & B500R

Type: Allison Transmission
⇒Models: B400R & B500R
⇒Versions: WTEC III, Gen 4 and Gen 5
⇒Service Intervals: Service intervals vary depending on vehicle application. Refer to preventative maintenance (PM) intervals or service manual.
⇒Filter cover bolts/nuts torque: 38-45 lb. ft. (51-61 N-m)
Drain plug torque 18-24 lb. ft. (25-32 N-m)
Oil service fill approximately 16 quarts (15 Liters)
Oil service fill approximately 30 quarts (28 Liters)


Oil filters can be replaced without having to drain transmission sump oil.





⇒Vehicle should be on level ground and wheels chocked.
⇒Wear personal protective equipment.
⇒Use caution when working with hot transmission fluid.





Allison High Capacity Filter Kit, Twin Filter Kit, Part #29548987
This kit contains all the O-rings, gaskets and filters for a complete service. There are extra O-rings included for different style applications.

Allison Filter Kit
Allison Filter Kit
Allison Filter Kit
Allison Filter Kit Contents



Allison B400R & B500R with versions of  WTEC III, Gen 4, and Gen 5 transmissions with 2″ sumps, use the same service filters. These filters are for “Main” and “Lube” and can be removed and replaced without removing the valve body.

Note: Allison filters installed at the factory are marked “Factory Installed” for warranty purposes.

Allison Filters
Factory Filters and Replacement Filters




Procedure: Note – B400R shown, same procedure for B500R. 


1. Remove oil drain plug (Oil filters can be replaced without having to drain transmission sump oil).

Allison, Valve Body, Fliters
Allison Valve Body

 2. Remove hex nuts to remove “Main” and “Lube” filter covers.

Allison, Filters, Covers
Allison Filters Covers

 3. Remove filter covers.

Allison Filter Covers
Removing Filters

 4. Remove old gaskets.

Allison Filter Change
Remove Old Gaskets

 4. Clean any old gasket materials from valve body and filter covers. Remove old O-rings from filter covers.

Allison filter Gaskets and O-rings
Clean Gasket and Remove O-rings.




1. Install new O-rings on filter covers. (Use the correct O-rings by matching them to the old O-rings.)

Allison Filter Seals
Filter Cover Seals

Note: Using the incorrect O-rings may cause damage to filter covers.

2. Install filters to filter covers.

Allison Filters
Filter O-rings and Filter Installed

3. Install gaskets to valve body.

Allison Filter Gaskets
Filter Gaskets Installed

4. Install filter cover assemblies into valve body.

Allison Filter Install
Filter Install

5. Install the twelve nuts securing filter covers to valve body.

Allison Filter Cover
Install Filter Cover Nuts

Note: Do not use nuts to draw in filter covers, damage can result to filter covers.


6. Torque nuts evenly to:
Filter covers 38-45 lb. ft. (51-61 N-m)
Drain plug to 18-24 lb. ft. (25-32 N-m)


7. Add fluid to transmission, start vehicle and check for leaks. Once vehicle is at operating temperature use shifter or Allison DOC to check for proper level. For information on transmission shifter functions. Go to;
Allison Transmission Shifter Functions and Prognostics










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