A/T Input Housing Assembly - Air Check

Number 83-I-65 Section 7 Date 04/83
Subject: INPUT HOUSING ASSEMBLY - AIR CHECK - THM 700-R4 TRANSMISSION
When disassembling a THM 700-R4 transmission, it is a good idea to air check the oil passages in the input housing assembly.

Air checking these passages will help you diagnose:

^ Blocked channels.
^ Crow channel leaks.
^ Clutches are or are not applying.
^ Checkballs are or are not sealing.

After the input housing assembly is removed from the transmission, perform an air check as follows:



1.. Adjust air pressure to approximately 30 psi.

2. Blow air into the hole nearest the end of the turbine shaft (hole marked #1 on illustration). Air blown into hole #1 will exit out the end of the turbine shaft around the checkball capsule. (Use care not to blow transmission fluid on your clothing or body.)

3. Blow air into the hole marked #2. This is the overrun clutch passage. The air from this passage will go past the lip seals on the forward clutch piston and exit through hole #3 on the turbine shaft.. If you place a finger over hole #3, to block the air flow, the overrun clutch should apply.

4. Air check hole #3. This hole should apply the forward clutch.

5. Air checking hole #4 should apply the 3-4 clutch.

6. The last hole on the turbine shaft is for lube supply to the internal components located along the output shaft. Any air blown into this hole should exit the one hole at the back of the turbine shaft which does not contain a sealing ball.