Need help identifying this b2600i 4x2 auto transmission

The bellhousing isn't stamped, but some of the parts are. I think they're interchangeable with other transmissions though, so here are some pics:







Needing to swap this one out or have it rebuilt and just want to make sure it's what I think it is (L4N71b?). Thanks.

As I understand that is the transmission these trucks sport. It's supposed to be a Nissan transmission. There should be 3 or four electronic solenoids on the driver-side. If it has three then it will also have a single vacuum shift actuator.

It could also be an L3N71B (3 speed versus 4?) but I think they are interchangeable.

I'm sure someone here knows definitively what they are... Dan

Dan,

Thanks. I believe you're right about them being interchangeable which is why I'm confused. I took a decent photo of the driver's side solenoids, but it's a little blurry. I'll have to look at it again to confirm. The transmission itself is by Jatco and has the model # X74622Z03968.

Here are a couple shots.



Lock up and oil pressure sensor.

Thanks again. These are some other pics I took while I had the truck jacked up. Couldn't seem to focus on the sensors and modulator properly with that camera unfortunately. I even ran this one through an unsharpening mask in photoshop, didn't help much, so I made it smaller. You can still make it out though:





I know everything looks rough, but I plan on cleaning the entire undercarriage. This truck belonged to someone who ran it up and down a dirt road for years without ever cleaning, which probably led to multiple problems I'm sure.

That is a vacuum operated upshift model, like mine. Looks like the one solenoid was replaced recently - on the right.

I bet you will see some markings when you clean it up. Dan

Yeah, got to looking at the placement of the markings on 3n71bs and 4n71bs and it's usually above that modulator I guess. I'll have to jack it up again (just recently got a decent 3 ton jack) and clean it up over the weekend.

Got under it the other day with a wirebrush and went to town. Now I have a sparkling clean tranny which still has no stamp where it should be. D'oh. I think the extension housing was swapped on it? Doubtful, but maybe.

Mine is on the right side on a tag on the shifter thingy next to the dip-stick tube. I noticed the first pic in this thread is of that exact location on the tranny but no tag. Hopefully adding some helpful info to an old thread.

Thanks for checking out the thread. I ended up having the old transmission swapped with a used one that was identical. Had to have it shipped here since the local salvage yards generally only have manuals instead of automatics. That tag you pointed out was on the original, but had been bent off, so I eventually removed what was left. It was pretty much a variation of the Jatco 4N71B, which seem to be scarce lately. I've been using the truck mostly to carry a jon boat to ponds and having a blast with it since the swap. They're awesome trucks.