Frequently Asked Questions
Find answers to Frequently Asked Questions for First Generation Firebirds that have been asked and answered on FGF. Special thanks needs to be given to all the FGF members who took the time to respond to other member's questions.
Transmission and Clutch - Clutch
Bulletin 68-I-27 — Pontiac Motor Division Dealer Service Information Bulletin, Section 7E, dated November 14, 1967. Attention: Service Manager.
Subject: 1965–1968 Turbo Hydra-Matic — Correct Usage and Installation of Center Support to Case Snap Ring and Intermediate Clutch Backing Plate to Case Snap Ring.
Short answer: Field failures after Turbo Hydra-Matic overhaul have been traced to incorrect snap ring usage and installation. The center support snap ring must be the beveled type (flat side toward the support, gap adjacent to band anchor pin); the intermediate clutch backing plate snap ring must be the flat type (gap opposite the band anchor pin).
There have been reports of incorrect usage and/or incorrect installation of these two snap rings, resulting in field failures after Turbo Hydra-Matic overhaul. The correct usage and installation must be as follows.
Center Support to Case Snap Ring
One side of this snap ring is beveled and one side is flat (the intermediate clutch snap ring, by contrast, has both sides flat). Use only the beveled snap ring. Install it with its flat side toward the center support and its locating gap adjacent to the band anchor pin.
Intermediate Clutch Backing Plate to Case Snap Ring
Use only the flat snap ring. Install the snap ring with its locating gap opposite the band anchor pin.
Content last modified: June 13, 2026 at 10:06 am
Bulletin 68-I-81 — Pontiac Motor Division Dealer Service Information Bulletin, Section 7E, dated June 18, 1968. Attention: Service Manager.
Subject: Incorrect Usage of Forward and/or Direct Clutch Driven Plates.
Short answer: Forward clutch and direct clutch failures after Turbo Hydra-Matic overhaul have been traced to mixing up the flat steel clutch driven plates. The forward clutch plate (.0775″ thick, P/N 8623849) and the direct clutch plate (.0915″ thick, P/N 8625197) are different thicknesses and must not be interchanged. Early- and late-type plates within each part number are interchangeable for service.
Use the correct plates as follows:
- The forward clutch in all 1965–68 transmissions uses the .0775″ thick, flat steel clutch driven plate, Part Number 8623849 [Z] (Gp. No. 4.163). The early type has no additional identification; the late type has four teeth shortened (2 on each side) and two teeth omitted (1 on each side), and is further identified by a “V” notch on one tooth (see Fig. 1 in the scan below).
- The direct clutch in all 1967–68 transmissions uses the .0915″ thick, flat steel clutch driven plate, Part Number 8625197 [M] (Gp. No. 4.163). The early type is identified by two diametrically opposite short teeth; the late type is identified only by four teeth shortened (2 on each side) and two teeth omitted (1 on each side) (see Fig. 2 in the scan below).
In addition, the waved steel clutch driven plate (Part Number 8623851) has also been revised. Both early and late types are .0605″ thick and are identified by a “U” notch on one tooth; the late type additionally has four teeth shortened (2 on each side) and two teeth omitted (1 on each side) (see Fig. 3 in the scan below).
The revised (late-type) plates are interchangeable with their early-type counterparts for service.
Content last modified: June 13, 2026 at 10:06 am
Content last modified: June 9, 2026 at 7:10 am
