TH400

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hoagster

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Sweet truck!
 

MrBubbles

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Found your thread in the search bar and I'm curious as I'm trying to track down a 4 pin connector on the side of my TH400 as well. Does it look like the picture attached?

I'm rebuilding what I believe to be a 1974 GMC P35 and am coming across more problems than I had planned for with swapping in a new engine and transmission.

The unknown device is mounted to a bracket down to the transmission pan and doesn't seem to be connected to anything other than the 4 wire connecter. I want to know what this thing is and whether or not I have to move it over to the new engine and trans and wire it back up.
 

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AuroraGirl

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Taylor
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1978, 1980
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K10, K25
Engine Size
400(?), 350
Found your thread in the search bar and I'm curious as I'm trying to track down a 4 pin connector on the side of my TH400 as well. Does it look like the picture attached?

I'm rebuilding what I believe to be a 1974 GMC P35 and am coming across more problems than I had planned for with swapping in a new engine and transmission.

The unknown device is mounted to a bracket down to the transmission pan and doesn't seem to be connected to anything other than the 4 wire connecter. I want to know what this thing is and whether or not I have to move it over to the new engine and trans and wire it back up.
im not quite sure what im seeing in the 2nd pic , a different angle if you could?

But the connector matches what the rear lighting harness on a 77 K25 plugs into the wiring for the truck(different length frames and different type rear lighting would have different harnesses)

Is this th475 have a prop brake on it
 

Bextreme04

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350-4bbl
Found your thread in the search bar and I'm curious as I'm trying to track down a 4 pin connector on the side of my TH400 as well. Does it look like the picture attached?

I'm rebuilding what I believe to be a 1974 GMC P35 and am coming across more problems than I had planned for with swapping in a new engine and transmission.

The unknown device is mounted to a bracket down to the transmission pan and doesn't seem to be connected to anything other than the 4 wire connecter. I want to know what this thing is and whether or not I have to move it over to the new engine and trans and wire it back up.
Like Taylor said… can’t see very much from that pic, but I can see the single wire kickdown connector on there, and that extra piece that the 4-pin connector supposedly connects appears to have several wires running up and over the top of the trans to somewhere. Where are those wires going? Can we get a better closeup of all of it?
 

mmerlinn

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460, 181, & 181
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 .

1976 up TH400 solenoid attaching bolts (2), speedo retaining bolts (1), and rear mount bolts (2) are metric.

ALL other TH400 bolts in all years were American, so if any bolt in the transmission other than those listed above is metric, then it CANNOT be a TH400.
 

Donald

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GMC 1500
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350 / 290
Aurora Girl hit it on the nose some one put a 4L60E connector in this trans . I think monster trans did the rebuild . I ordered a new one , single pin . Thanks all .
 

AuroraGirl

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400(?), 350
Aurora Girl hit it on the nose some one put a 4L60E connector in this trans . I think monster trans did the rebuild . I ordered a new one , single pin . Thanks all .
i dont think thats possible.. unless its for spark control stuff , emissions/power related things?
 

Donald

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GMC 1500
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350 / 290
Sorry I meant a 700r4 plug your right the 4l60e has a different pass through many more wires . I have an excuse 79 years old .
 

mshawn

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350,378,482
No lock up, kick down and reverse are the only wires I can think of. How sure are you it’s a 400?
Kick down reverse and neutral switch ground
 

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