TH400 Pump 1964-67, used and ready to install. Fits the TH400. Ships fast from the USA.
Early Turbo 400 pumps are getting scarce, and a car from 1964 to 1967 with a fixed-stator converter cannot use just any TH400 pump off the shelf. This is an original GM first-design 8-bolt pump, the kind found behind the Buick nailhead V8, in good used condition with a new front bushing and a new front seal already installed. It still carries its original black .625 in. pump gears, and the castings are 1358649 and 8623073. If your early TH400 whines with engine speed, takes its time going into gear, or slips everywhere, this is the correct pump to rebuild it with.
The pump is the front cover of the transmission and its only source of pressure. The converter drives the inner gear, which turns the outer gear inside the pump body, and the trapped oil is pushed past the pressure regulator into the line circuit. From there it applies the forward, direct and intermediate clutches and both bands, fills the converter, and returns through the stator shaft as lube oil for the gears and bushings. The gear width is matched to the pocket depth in the body, which is why first-design .625 gears and later pump bodies cannot be mixed.
A low fluid level, clogged filter or failed filter O-ring causes the same noises, so rule those out. Then test line pressure hot and cold: GM's service chart gives about 60 to 90 psi in Drive at 1000 rpm, modulator connected. Low readings in every range with a healthy modulator point to the pump. The TH400 pump failure guide has the pressure tables, and TH400 filter and pan service shows how to check for the debris a worn pump leaves behind.
This pump is for 1964-67 TH400 units without the variable pitch (switch-pitch) converter. It is not correct for switch-pitch transmissions, which have a two-prong plug on the case and need a narrow-spline stator support; those take the 1965-1967 switch-pitch pump. Before ordering, check that the casting numbers on your old pump match 1358649 and 8623073; matching castings is the surest way to a correct fit. If the numbers on yours are different or worn off, send us a photo with your year, vehicle and VIN and we will tell you whether it fits. Other early parts are on the TH400 parts page.
Pair it with the TH400 overhaul kit for fresh gaskets and seals, and if the valve body is varnished from running hot, look at the TCI TH400 valve body.
| Fits | TH400 1964-67 |
| Part type | Pump |
| Condition | Used |
| Brand | OEM |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. This is the non-switch-pitch first design. Switch-pitch transmissions have a two-prong case plug and need a narrow-spline stator support, so they take the separate 1965-1967 variable pitch pump.
This pump carries castings 1358649 and 8623073. Match those numbers on your old pump, or send us a photo with your year and VIN if yours are different.
It is a used original GM pump in very good condition with a new front bushing and new front seal. It keeps its original black .625 in. pump gears.
No. Gear width must match the pocket depth of the body it runs in, so this body runs .625 in. gears. Keep the gear set with the body.
Prime the pump with DEXRON, confirm line pressure with a gauge, look for leaks at the front seal and pump O-ring, and set the fluid level at operating temperature.
