Hello, I am digging for some general information. I have a '78 F250 4X4 with the np435 and 205 married. Now the 435 that is in the truck right now is very worn out. I do not think the person I bought the truck from realized how bad of shape the tranny was in, and probably did some serious damage by continuing to drive it. I, however, recently purchased a fresh 2wd np435 for a good price, thinking that I could swap out the tailend of the 4wd version I have with the new 2wd version. I did not realize that the hole spacing was different at the time. Is it possible to modify the new 2wd case to accept the tailshaft from the 4wd assembly? What would be involved? I haven't pulled the 4wd tranny out of the truck yet, so I haven't been able to get a good look at it to get an idea of what might be involved. I am used to making things work that aren't supposed to I know it would be easier to use a 4wd np435, but I don't have one and I really haven't noticed any for sale in my area for a good price.

Because I have both the 2wd and 4wd versions, I was thinking another option would be getting a rebuild kit, and then swapping the guts out of the 2wd case into the 4wd case, and replacing the bearings and seals along the way. That however is more involved than I was really wanting to get into. Anyway, any ideas or thoughts?

Morgan.

 

Along with the tail shaft swap you need top swap the output shafts as well so you may as well rebuild it and just use the 4x4 case. There is no need to spend the time trying to make something fit when you have to break the trans down anyways.

 

Thanks, I was hoping not to have to get into a full rebuild, but I gotta do what I gotta do. Like I said, I expect some parts inside the 4x4 case to be grenaded, so I guess I will do a rebuild, and scavenge parts needed from the 2wd drive case that are not included with the rebuild kit.
Thanks, Morgan.

 

If you need any internal pieces I have a 4x2 435 tore down and just sitting at the shop.

 

FWIW, my 2wd tranny from my 86 F250 had the parallelogram shape(4x4 type) Not sure if all 80's trannies are like mine, but it may be worth searching. How long is the tailshaft on your 2wd tranny? F250 "highboys" had a short shaft for divorced tcases. The f150 2wd version,I believe, had a long tailshaft, which with early bronco crowds, works with their Dana 20 tcase. pics are in my last gallery.

 

NO kidding? I struck out from every direction then. I have a '66 Bronco and was thinking that I might be able to swap the 2wd np435 into it, but I have the short tailshaft version. I'll probably do some more checking on that though. The bronco currently has a 3sp manual and I would prefer to have the np435 in it.

So where I stand right now, I guess I am just going to have to do a full rebuild on the 4x4 cased that I have, and see if I can make use of the 2wd case in my bronco. Thanks again.

 

If your 66 bronco had the 3 sp. and 170 cid, your tcase adapter should be the long one already. I had the exact same bronco, and I kept the dana 20, adapter, and have an np435(in my gallery) from a '72 f100 that mounted to a dana 21(again, gallery). It seemed that was the tranny to use, cuz it had the spud shaft already on there. Advance adapters had the conversion spud needed. I never got around to doing the swap, but I kept all the parts, where they're gathering rust. The bronco was cut up after somebody shot it up while parked at our hunting shack.

PS: I think the adapter needed to be bored out to match the dana 20's bearing IIRC. Advance Adapters again had the info.

 

All right, I'll check it out to see what all I would need to make the bronco project work. I am also planning on switching to the 250 I6 engine which is the 170's bigger brother. So if I'm gonna be swappin stuff around, I might as well get exactly what I want in there. Hopefully I will be able to make use of this extra np435. Thanks to everybody.