Transfer case Removal Question/ Now Install

[ep67bro]

On my 67 bronco I have an NP-435 manual trans and a stock Dana 20 transfer case. I need to pull the transfer case out to replace the gaskets between the adaptor, transmission, and the transfer case since I have a major leak. I cant remember if I need to do anything with the transmission to prevent the roller bearings from falling out or is this just for the 3 speed RAN/RAT trans? Should the transfer case be in gear or neutral?

I have pulled and installed this transfer case before but it was over 15 years ago and I cant remember. Anything else I need to remember when doing this? I have forgotten more than I know these days!

 

[Johnnyb]

I have just done this and as long as you don't pull on the output shaft of the NP435 it should be fine. Support the transmission and remove the crossmember first, then D20 off adapter and adapter off NP435.

-JB

 

[Broncobowsher]

Pretty sure the transmission should be in a gear. Don't think it matters what gear so long as it is in a gear. Just to minimize the output shaft from pulling out and dropping stuff out.

 

[ep67bro]

Ok thats what I thought. I have been dreading pulling this T case for over a year now. Time to man up and just do it!

 

[ep67bro]

Well this didnt go as expected. I removed the transfer case last week. Managed to do it with out taking the exhaust off. Found the aluminum NP-435 adaptor was loose on trans, I mean really loose, so that was where my leak was coming from for sure. I removed the bolts that connect it to the trans and it wouldnt come off.... well I forgot that there is one small bolt that goes from the trans to the adaptor from the inside of the trans!!!! You have to take the top cover off to get to it!.

So it looks like I now have to drop the trans out of the truck to get to that bolt to remove it, clean and reseal everything. I used red thread locker back when I put this together 15 years ago. Guess it wasnt enough. Not looking forward to taking that 90 lbs hunk of steel out of the truck laying on my back. Going to break down and get a transmission jack and force myself to move forward this week. I dont enjoy this as much as I used to!

 

[Apogee]

FWIW...more like 120 pounds for an NP435.

 

[ep67bro]

FWIW...more like 120 pounds for an NP435.

LOL yeah I guess it is more. I put it in by myself when I as much younger, stronger and stupid! It could be 20 lbs these days and it would be too much! I just picked up the biggest transmission jack that Harbor Freight had. I will try and tackle it in the next few days, one issue I have is getting the shifter out of the trans, I know you should be able to push down and turn counter clockwise to remove it but I remember way back when I put it in that I never could get it out that way. Oh well this simple day or two project is turning out to be a real PITA!

 

[Apogee]

I feel you. I have a set of big channel locks that I use to push down on the sheet metal retainer for the shifter, as it has some decent teeth on it. I wrap the stick with a rag so I don't tear up the retainer, and then slip the jaws loosely over the "cup" portion of the top of the retainer, lean into and rotate...usually comes right out.

 

[Johnnyb]

well I forgot that there is one small bolt that goes from the trans to the adaptor from the inside of the trans!!!! You have to take the top cover off to get to it!.

Wait a minute, I have done several of these and never bolted from inside the NP435 to the adapter (AA adapter, homemade adapter, etc.). Is that truly a thing? My AA adapter is only bolted externally?!?

https://www.advanceadapters.com/Att...loadGuid=1f7939f2-ab58-44fc-a5b8-27a4a6ed5fbd

-JB

 

[mrdrnac]

Had to clearance my AA Adapter on the top right corner by the bolt hole to get a bolt in from the outside and it was slightly shorter than the other bolts to make sure it didn't hit the gear on the inside of the transmission.

 

[thegreatjustino]

Wait a minute, I have done several of these and never bolted from inside the NP435 to the adapter (AA adapter, homemade adapter, etc.). Is that truly a thing? My AA adapter is only bolted externally?!?

There have been numerous different designs by AA over the past 40 years. There's at least one version that uses a bolt on the inside of the transmission and a nut on the adapter side.

 

[ep67bro]

Wait a minute, I have done several of these and never bolted from inside the NP435 to the adapter (AA adapter, homemade adapter, etc.). Is that truly a thing? My AA adapter is only bolted externally?!?

https://www.advanceadapters.com/Att...loadGuid=1f7939f2-ab58-44fc-a5b8-27a4a6ed5fbd

-JB

Mine is not an Advance Adaptor. It was a Dynamic Concepts Adaptor. I believe he was a member of this sight back in the day. It utilized the upper right hand hole in the trans and through bolted into the machined adaptor.

 

[Broncobowsher]

That's a new one to me. Amazing that after all this time I am still finding new ways things were done in the past.

 

[ep67bro]

See the pictures and description below. I didnt make it up LOL. The adaptor worked fine for a while, it was at least 15 years since i did the trans swap in this truck. The oil leak started getting bad about 2 years ago.

 

[Johnnyb]

See the pictures and description below. I didnt make it up LOL. The adaptor worked fine for a while, it was at least 15 years since i did the trans swap in this truck. The oil leak started getting bad about 2 years ago.

I don't know if I would be comfortable with a bolt that could unthread and get into the gears! Especially after your loose adapter experience, Use much threadlocker.

-JB

 

[thegreatjustino]

See the pictures and description below. I didnt make it up LOL. The adaptor worked fine for a while, it was at least 15 years since i did the trans swap in this truck. The oil leak started getting bad about 2 years ago.

This brings up another leak point. Is the leak from between the transmission and the adapter plate, between the adapter plate and 6-cyl adapter, between the adapter and Dana 20, or all three?

The plate shown in the installation instructions is used in conjunction with a stock EB 6-cylinder adapter. This creates a two piece adapter, not the much more common one piece.

 

[ep67bro]

Leak was between the adaptor plate and the trans. The seal between the adaptor plate and 6cyl adaptor housing was good. And I assume the only reason it leaked was because the bolts became loose so it started moving around and broke the seal.

I did some digging and it looks like I did this trans swap back in 2009! I didnt have two cents to rub together then. The trans was out of a junk F250 I had bought for parts back when I was into Bump sides and was full of water, the 6cyl adaptor I got off this sight for a few bucks and the adaptor plate I bought off a member that was making them on the side and it was by far the cheapest option to get some low gears for wheeling.

This set up has been run on the highway, and wheeled many times in those years so I cant complain about the product, just it suck I got to pull the trans to fix it. maybe this afternoon I will get out there and try to remove the shifter, take the trans tunnel plate off and rig up the trans jack....or maybe I will just sit and surf the internet!! LOL

 

[Broncobowsher]

I remember the that adaptor. Somewhat popular for a cheap NP435 swap for a few years. Didn't realize they ran a bolt from the inside, I thought it was just run 3 bolts and be done with it. That was shortly after I pulled my 435 and went 4R70W and was one of the first (but not the first) to run one in a Bronco.

 

[ep67bro]

So the trans is out, I am cleaning everything up.
I was hoping to find the pig tail to the wiring harness for the back up lights. I havent had working back up lights on this truck in almost 20 years. The switch in the trans works and is in good shape but I need the female wiring harness that plugs into it so I can wire in the harness under the dash. Anyone know a source for them? I looked at the vendors and couldnt find one but I remember years ago someone had them available. Hell I may have even bought one but have sold off most of my spare parts so I dont know where it is.

 

[ep67bro]

The fun just keeps coming. turns out the seal on the input shaft has been leaking oil into the bell housing. I pulled the input shaft bearing retainer and i am not sure the seal in in correctly. See the two attached pictures. i think its in backwards, the flat face should be facing the bearing not the fly wheel correct? That would explain why I have had a small amount of gear oil from time to time drip from the bell housing! Anyone can confirm this for sure?