A/T - THM 125/125C New Case Design
Number: 84-34Section: 7A (VIIc)
Date: Dec., 1983
Subject: NEW TRANSMISSION CASE FOR THM 125/125C
Model and Year: 1984 CELEBRITY, CAVALIER AND CITATION
TO: ALL CHEVROLET DEALERS
Beginning 1984 production of the THM 125/125C transmissions, a new transmission case went into production. The changes in the 1984 THM 125/125C transmission case are as follows:
CHANGES IN THE 1984 125/125C TRANSMISSION CASE
1. The manual shaft hole was made larger in diameter to accommodate a larger manual shaft.
2. The manual shaft seal bore was made deeper to accommodate a double lip seal.
3. The transmission case casting was changed to accommodate a neutral start switch.
4. The low and reverse snap ring groove was moved toward the cast sprocket face to accommodate thicker low and reverse clutch plates.
NOTICE: The new 1984 THM 125/125C transmission case cannot be used to service any models prior to the 1984 models. The past style transmission case (1983 model or earlier) cannot be used to service the 1984 THM 125/125C transmission.