NP203 removal question

[jcondo]

I have an np203 with a th350, the tranny needs rebuild but im not sure how it unbolts from the np203.
From what I can tell I have to split the np203 from the adapter plate and take the bolts out of the tranny from inside the 203 plate. which means I can leave the cross member bolted in until im ready to drop the transmission.
Is that correct?

[sweetk30]

unbolt adapter from face of 203 unit .

then hold up trans .

then unbolt adapter from trans .

then remove trans .

dont forget np203 takes 30w oil only . NOT atf or gear oil .

[mongocanfly]

And its heavy...

[jcondo]

Originally Posted by sweetk30

unbolt adapter from face of 203 unit .

then hold up trans .

then unbolt adapter from trans .

then remove trans .

dont forget np203 takes 30w oil only . NOT atf or gear oil .

Thanks, I figured I was correct when looking at it from under the truck, just wanted to make sure.
I had previously already drained and refilled the 203. now I get to waste good oil with less then 50 miles on it.
lol I know its heavy, so im waiting for a transmission jack so I can do this solo.

[sweetk30]

i just drained my 203 range box on my doubler kit . i had to pull the pto cover as even the lowest front face bolt didnt go 100% threw and let oil drain out . so you should be good but dont quote me 100% plan ahead .

and you think your 203 is heavy try a half of a 203 and a full 205 as one unit .

[jcondo]

yea I can imagine that's not a light job.
Im trying to keep this 77 k10 all original or id swap it for a transmission and 205 that's in my next project truck. My plan is to drive this truck in the winter and the other in the summer months, since they put way too much salt on the roads up here in iowa.

[Getter-Done]

A few years ago ( 30 something)
I had a 76 Blazer
with 454 /350 turbo/203 tc
I welded a piece of round stock
that fit in a floor jack
To a piece of flat plate.
then welded a plate to that plate match the offset angle of
the 203.
Put a chain around it and was able to do it by myself.
As I recall I set The round stock 3 inches off center to balance the transfer case.

[SunSoaked]

Originally Posted by sweetk30

i just drained my 203 range box on my doubler kit . i had to pull the pto cover as even the lowest front face bolt didnt go 100% threw and let oil drain out . so you should be good but dont quote me 100% plan ahead .

and you think your 203 is heavy try a half of a 203 and a full 205 as one unit .

That pic is 9 years old. Does it still look like that? I love the green, I'd like to see that color on the truck with black accents.

[sweetk30]

yep almost as clean since it was hung in a frame under cab and stored for that long . then i parted that project and used it in my budget beater build .

[jcondo]

Well I got the transmission, and transfer case out. Now to clean it up and send the transmission in to get rebuilt.
Still not sure if I wanna try and install it in 1 piece or 2 yet tho when I get it back.

[sweetk30]

floor hump that unbolts = win win if you have a engine hoist .

hoist it all up and in then use a floor jack to stabilize it .

[jcondo]

Yea I don’t have an engine hoist or a transmission jack currently. Looking into them possibly after the holidays.
Any ideas on where I can get the gaskets and o-rings for the adapter plate? I’m having issues when I google them.

[sweetk30]

any local trans shops to you ?

if not call these guys they will get you covered . www.offroaddesign.com

remember DRY no atf on this stuff during install if you can help it .

UPDATE : if your trans is getting remaned then it should come with the rubber square lip o-ring . the t-case gasket they might be able to get just him . but i just got a master gasket & seal kit shipped off ebay from transtar for under 25.00 bucks . https://www.ebay.com/itm/GMC-NP-203-...72.m2749.l2649

[jcondo]

The shop I’m taking it to is 1 hr 15 mins away. I’m gonna ask them about the gaskets I’ll need. In the mean time I’m just trying to see what I can find if they don’t have anything.
Thanks for the link.