Mystery transmission

[mcallimr]

I have an 88 1500 with a 5.0 and the original tranny went out, I bought a 700r4 off a gentleman who said he pulled it off an 89, after pulling the old ok I realized how different they were from each other. The bolt pattern was the same and the length didn’t look too different and the torque converter would not bolt up. Does anyone have any idea what transmission this is?

 

[NickTransmissions]

No mystery - He sold you a TH400. Why is the filter out of it?

Also, do you still have your orig 700R4?

 

[mcallimr]

He sold me a 700r4 the original transmission is a th400 then

 

[mcallimr]

The photos are of the transmission I pulled

 

[NickTransmissions]

The photos are of the transmission I pulled

Sorry, read it backwards. That said, I would think you'd have a 700R4 in that truck, not a TH400 anyway. It's a half-ton, right?

Is the engine stock with its original TBI, etc?

 

[Schurkey]

I would not expect a 1500 to have a TH400.

One wonders if the original TH700 died, and the owner at that time put a 400 into the truck knowing the 700s were fragile.

Did the kickdown work? The kickdown should be computer controlled; and I'd expect the OEM computer wouldn't know how to handle a TH400 kickdown (but would be set-up to engage a TH700 converter clutch.

 

[someotherguy]

There's definitely early 1500's that came with the TH400. Not sure why one would be equipped that way but I owned an example, and it was a RCSB C1500 with the 4.3 V6. No overdrive on the gear indicator in the cluster. SPID label wasn't legible but truck had no indication of having been transmission-swapped.

If OP's SPID label is legible then that would tell the story, or if the VIN is still on record and can be decoded -> https://www.gmpartsgiant.com/vin-decoder.html

Richard

 

[PlayingWithTBI]

There's definitely early 1500's that came with the TH400. Not sure why one would be equipped that way but I owned an example, and it was a RCSB C1500 with the 4.3 V6. No overdrive on the gear indicator in the cluster. SPID label wasn't legible but truck had no indication of having been transmission-swapped.

If OP's SPID label is legible then that would tell the story, or if the VIN is still on record and can be decoded -> https://www.gmpartsgiant.com/vin-decoder.html

Richard

So far, every VIN Decoder Site, I’ve never got any results for my 88. It seems they only go back to the early 90s, YMMV

 

[someotherguy]

So far, every VIN Decoder Site, I’ve never got any results for my 88. It seems they only go back to the early 90s, YMMV

All the more reason to get a picture of the SPID label any time you buy a truck, even if it's messed up, the remaining codes that may be legible might help at some point in the future. At least we can decode 'em ourselves.

Richard