Electra Park Avenue V8-307 5.0L VIN Y 4-bbl (1984)
Planetary Gears: All Technical Service Bulletins
A/T - Loss of Reverse/Second and Third Gear Ranges
Bulletin:
84-7-8
Date:
Oct. '85
Ref. No. 85-306-7
SUBJECT:
STRIPPED INPUT DRUM SPLINES RESULTING IN A LOSS OF REVERSE, SECOND AND/OR THIRD GEAR RANGES
MODELS AFFECTED: SOME 1984 AND PRIOR MODEL THM 200-C, 200-4R AND 325-4L TRANSMISSIONS
Some 1984 and prior model THM 220-C, 200-4R and 325-4L transmissions may have stripped input drum splines resulting in a loss of reverse, second
and third gear ranges (refer to illustration).. In mid 1984 production, the drum was hardened in the spline area to prevent the possibility of this
occurrence. The new hardened drum may be recognized by a black appearance from the heat treat process.
Any time a 1984 or earlier THM 200-C, 200-4R or 325-4L transmission is disassembled the input drum should be inspected to see if it is one with
hardened splines. If not it is recommended that a new drum part number 8648360 be installed.
Refer to the appropriate Service Information Manual for proper installation procedures.
