Np203 input gear swap

[goathearder]

Hey all, I recently broke my np203 and was lucky enough to find a used one. The problems I have a th350 and the used one is from a th400. That means thoe input gears are different so I am curious what it takes to swap one out.

I have found a few articles about how to take the range box off and I looks like it might be a giant pain so I am curious if anyone had done it and might have some insight for me.

Thanks in advance,
John

 

[sweetk30]

got to split the tcase then pop out the gear and swap it with the other.

i did a reman of a 203 range box only.

 

[goathearder]

Damn, that is what I was afraid of, basically gotta take the whole thing apart I think. When you did the range box portion did you remove it from a full t-case or was the range box already seperated?

I am just curious if I need to take the tail section off before I can split the range box from the chain case.

 

[sweetk30]

full case. but been so darn long i forgot at this point. and i only wanted the box so i didnt care and just pulled it and scrapped it.

 

[goathearder]

From my research, it looks like I gotta take the tail section off to remove the shift fork before I can pull the range box out.

Its a good thing I have a part time conversion shaft coming cause I don't want anything to do with all the needle bearings in the tail cone.

 

[goathearder]

Well I don't know how I got this lucky but I picked up the used tcase tonight and it has the correct 27 spline input for my 350 already. I am not sure how that happened coming from a th400 but I'm not complaining.

 

[sweetk30]

could have had it behind a 400 with aftermarket output shaft cut for 27 spline.

 

[owenst7]

It's really not that bad to take apart. Actually, the hardest part is moving the damn thing around on your bench cuz it weighs so damn much.

Everyone complains about the needle bearings...Take the tailcone off and hold a cup under the rear output shaft. If you spin the shaft (clockwise?), the needle bearings will ride out of their collar and drop in to your cup. There's 3 layers of them and they have thrust washers in between them. When you are ready to put them back in, buy a tub of Assemblee Goo from NAPA. That stuff is super handy and you can literally stick like 10 needle bearings to your finger at a time with it.

http://www.amazon.com/Lubegard-19260-Blue-Assemblee-Soft/dp/B000B8UPCY