TH400

Donald

Member
Joined
Jun 24, 2018
Posts
40
Reaction score
52
Location
Loris SC.
First Name
Don
Truck Year
1985
Truck Model
GMC 1500
Engine Size
350 / 290
I have a TH400 in my 31 Chevy pickup , the trans has a 4 pin weather pack style connector . I have never seen a 400 with more then 2 pins . Did GM have a lockup convertor ?
You must be registered for see images attach
 

nvrenuf

Full Access Member
Joined
Jul 30, 2010
Posts
1,061
Reaction score
615
Location
Mobile, Al.
First Name
John
Truck Year
1991
Truck Model
K5
Engine Size
454
No lock up, kick down and reverse are the only wires I can think of. How sure are you it’s a 400?
 

Vbb199

B-rate Hillbilly Customs
Joined
Jan 12, 2018
Posts
8,022
Reaction score
12,754
Location
Salisbury NC
First Name
Vince
Truck Year
89, 79
Truck Model
89 Suburban R1500, 79 C10
Engine Size
350, 502
Sounds like it's a 700r4 in there.

Does it have a big round cover about 4" on the passenger side of the trans?
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
7,670
Reaction score
4,329
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
I have a TH400 in my 31 Chevy pickup , the trans has a 4 pin weather pack style connector . I have never seen a 400 with more then 2 pins . Did GM have a lockup convertor ?
You must be registered for see images attach
Are you sure this isnt a
You must be registered for see images attach

One of these guys. Im guessing early 4l60e unless the PN switch wiring is on the external switch and this is the wiring going into the case
 

Donald

Member
Joined
Jun 24, 2018
Posts
40
Reaction score
52
Location
Loris SC.
First Name
Don
Truck Year
1985
Truck Model
GMC 1500
Engine Size
350 / 290
Yes it is a. 400 I worked for GM dealers and rebuilt many 400's .It is a metric trans at least the bolts in it are .The connector AuroraGirl has pictured is what I have . I think this trans is from Monster transmission , they must have used that instead of the correct one . Looks like I will have to pull the pan and check the wiring .



at
 
Last edited:

Vbb199

B-rate Hillbilly Customs
Joined
Jan 12, 2018
Posts
8,022
Reaction score
12,754
Location
Salisbury NC
First Name
Vince
Truck Year
89, 79
Truck Model
89 Suburban R1500, 79 C10
Engine Size
350, 502
OK now you got me interested. What motor is in the 31?

I know the th400 was used behind other mfgs like Chrysler, Ferrari, Rolls Royce, and I think also jaguar
 

Matt69olds

Full Access Member
Joined
Jan 8, 2018
Posts
1,675
Reaction score
2,189
Location
Central Indiana
First Name
Matt
Truck Year
81
Truck Model
GMC 1/2 ton
Engine Size
455 Olds
If your absolutely sure it’s a 400, someone has swapped the case connector. I have used the single wire 400 case connector on 700 swaps, I suppose the case connector would interchange the other way. Since it didn’t come stock that way, you will need to drop the pan and figure out what has been done.

Every 400 has a kickdown solenoid, some had a pressure switch on the 3rd accumulator passage on the valve body for transmission controlled spark (basically delayed spark advance until the car was in 3rd gear) the early BOP 400 had a switch pitch (basically a 2 speed converter) so at most you would need 3 wires. Since Chevy never had the switch pitch converter, and I seriously doubt you have functional spark control, a single wire connector is all you need.
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
7,670
Reaction score
4,329
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
OK now you got me interested. What motor is in the 31?

I know the th400 was used behind other mfgs like Chrysler, Ferrari, Rolls Royce, and I think also jaguar
fun fact, BMW used a 4l30e
 

Donald

Member
Joined
Jun 24, 2018
Posts
40
Reaction score
52
Location
Loris SC.
First Name
Don
Truck Year
1985
Truck Model
GMC 1500
Engine Size
350 / 290
The 31 has a 350 with aluminum angle plug heads , Edelbrock dual 4 air gap manifold of course Edelbrock carbs , MSD ignition and box . TH400 and a Richmond quick change rear . By the way thanks for the input . Don
 

Attachments

  • IMG_1104.JPG
    IMG_1104.JPG
    138.1 KB · Views: 17
  • IMG_1106.JPG
    IMG_1106.JPG
    138.9 KB · Views: 19
  • IMG_1094.JPG
    IMG_1094.JPG
    130.3 KB · Views: 18
  • IMG_1102.JPG
    IMG_1102.JPG
    126.6 KB · Views: 16

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
7,670
Reaction score
4,329
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
I admire the type 2 / TC saginaw ps pump, as well as the delco cs130 alternator, but if you ever want more power or just a better alternator, you can get an ad230 in the same ear setup and also chrome/shiny and the pulley would go on it, allowing it to take its place. the wiring is 1 to 1 adaptable or repinnable. They also make 1 wire versions
 

Forum statistics

Threads
35,533
Posts
747,401
Members
24,452
Latest member
Doug O
Top