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NP203 Removal from 74 Blazer with TH350

Chief Brody

Chief Brody

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I guess I will go ahead and start this thread now because I already got questions before I even look under there. My plan is to remove the NP203 and then remove the engine an transmission as a unit.
I am not getting rid of the NP203, but I want to clean it up and install the part-time kit. I need to determine if it needs to be reconditioned and if the chain needs replacing.

I have a manual which has no pictures for the NP203.

1. Can you remove the cross member without anything falling down on you?

2. The manual simply says "drain the case"....how do you do that?

3. Can I remove the T-Case with a floor jack or should this be done with the engine hoist through the tunnel?

4. The manual says "move the transfer case to the rear until the input shaft clears the adaptor". Is there enough slack to do this through the tunnel?

5. If using the hoist, what's the best way to fasten the hoist to the T-Case? "Using a chain" isn't specific enough...do you just wrap it or do you utilize existing bolts in the transfer case through a link in the chain?
 
If you look at the 203 from the rear, you will see the big round aluminum cover on the right hand side. Simply remove the lowest bolt cover and the fluid will drain out.

If I were you and doing the engine/tranny removal as a unit, I'd do those first and do the 203 last. Just leave the 203 bolted to the crossmember and remove the engine/tranny. Make sure you remove the floor hump cover to aid in getting to the adaptor bolts easier. Once the motor/tranny are out, use the cherry picker to support the 203 from the top inside the cab and simply lower it to the floor. Use a creeper or small sheet of plywood under the 203 to slide it out from under the truck.
 
I've removed a NP203 from a TH350 some time ago. Here is what I recall. The NP 203 is very heavy. So be sure to not be directly under it. If it falls on you that would hurt badly.

I had made a cradle to attach to my jack to support the tcase. This worked really well. After unbolting the tcase from the adapter I moved it back some and the cradle support the case. Then I lowered my jack. Again this case is so heavy be sure your arms are clear from it.

I don't know about removing the cross member and tunnel. Doing what I did above worked. I did not remove the floor cover.

The cradle was made of welding bars the were bent around the tcase. Then a rod was added so it could fir in the floor jack cradle.

just my 2 cents. Maybe other have some better solutions.

Maybe a tranny jack with some chains. Just be sure that the tcase is not going to move on you.
 
check out page 4 and 5 of my build thread.
http://coloradok5.com/forums/showthread.php?t=273066&page=4

It shows me re-installing that combo on a 73 k5. Their is also quite a bit of advice from others their including pictures. And then i show you how NOT TO DO IT :haha:. The Crossmember and transfercase brace going back down the right side are all that hold it up their IIRC so dont drop that crossmember all the way until you got a jack under it.
 
Well in my younger years I benched the 203 3 times in one month, now I use equipment to do it.
The cross member can be dropped first if you are removing the 203 first using a jack or the engine hoist. You need to support the Tcase though before you unbolt it if you do remove the cross member first.
I always take it out first.
ANd yeah the drain is the lower bolts on the aluminum flat cover that looks like a flower.:D
Also be sure you support the Tcase in multiple locations because it's lopsided and it will want to drop the side as soon as you unbolt the last bolt.
Chief Brody said:
I guess I will go ahead and start this thread now because I already got questions before I even look under there. My plan is to remove the NP203 and then remove the engine an transmission as a unit.
I am not getting rid of the NP203, but I want to clean it up and install the part-time kit. I need to determine if it needs to be reconditioned and if the chain needs replacing.

I have a manual which has no pictures for the NP203.

1. Can you remove the cross member without anything falling down on you?

2. The manual simply says "drain the case"....how do you do that?

3. Can I remove the T-Case with a floor jack or should this be done with the engine hoist through the tunnel?

4. The manual says "move the transfer case to the rear until the input shaft clears the adaptor". Is there enough slack to do this through the tunnel?

5. If using the hoist, what's the best way to fasten the hoist to the T-Case? "Using a chain" isn't specific enough...do you just wrap it or do you utilize existing bolts in the transfer case through a link in the chain?
Click to expand...
 
I used a motorcycle jack on the cross member and pulled the th350 203 combo as a unit. I was not bad at all with my friend helping.
 
thatK30guy said:
If I were you and doing the engine/tranny removal as a unit, I'd do those first and do the 203 last. Just leave the 203 bolted to the crossmember and remove the engine/tranny.
Click to expand...

wes you cant do this on a 203.

the tcase adaptor gets bolted to tranny first then those 4 bolts (th350) or 6 bolts (th400) get covered up when you bolt the tcase to the adaptor. you must drop the tcase first to then remove the tranny.

if me i woud drop tranny and tcase as 1 unit with atv jack or small tranny jack and a helping hand from a friend. then split them as 1 . if you cant do this then drop tcase first then tranny.

i would pull the engine by its self. and note pull the dist cap/coil first before you let the engine tilt back to firewall when tranny off or it can/will snap the dist cap or coil . ask a lot of us how we know this :doah:
 
Oh crap! Forgot about the adaptor bolting to the tranny first and then the 203!

Pardon me but I'm not totally 100% today after a rough night of drinking.
 
sweetk30 said:
and note pull the dist cap/coil first before you let the engine tilt back to firewall when tranny off or it can/will snap the dist cap or coil . ask a lot of us how we know this :doah:
Click to expand...

This is good stuff...you don't get this out of a manual.
 
sweetk30 said:
:whistle: humm i see how you got mixed up . :haha:
Click to expand...
You should have seen what was mixed up for drinks last night. :doah:

I haven't puked alcohol-wise for a long time. I mean a loooooooooooooong time. I remember puking in the trash can up at the shop and then this morning when I woke up. Did that 3 times this morning over the trash can here at home. :doah:

And then theres the favorite quote: "I'm never drinking again!" :whistle:
 
I use a tranny adapter in my floor jack to do a transfer case R&R...you can make one pretty easy if you cant get one from Harbour Freight,or another source.I had one I made that was just a peice of pipe that fit in the floor jack saddle hole,with a steel pipe floor flange screwed onto it,with a peice of 3/4" plywood I doubled up ,bolted to the pipe flange...used a chain around the t-case bolted to the plywood for safety--you definately dont want a NP203 landing on you--it'll be fatal most likely,or bust an arm at the least...

I found the tranny adapter for my floor jack at a flea market,paid 35 bucks for it--found out a new one isn't all that much more!..well worth it though,I use it to hang doors,R&R gas tanks,etc..very handy thing to have..
 
I got the 2 ton Harbor Freight engine crane on sale and with 20% off coupon for $159.00 so I am getting closer to doing this.

Someone said they used ratchet straps on the NP203...whats the bet way to use them and why do you really need to drain the fluid out of the case?
 
you dont drain the fluid it will drain on you when you pull adaptor bolts. :eek1:

and MUCH better to do before before droping from the truck trust me. :thumb:

and 1 time you dont drain before pulling and it tips on side and pissis out 2+qt of oil all over you will be saying i should have drained it first. :whistle:
 
sweetk30 said:
you dont drain the fluid it will drain on you when you pull adaptor bolts. :eek1:

and MUCH better to do before before droping from the truck trust me. :thumb:

and 1 time you dont drain before pulling and it tips on side and pissis out 2+qt of oil all over you will be saying i should have drained it first. :whistle:
Click to expand...
^^^^^^^^^ What he said.^^^^^^^^^^^^^^^^^^
 
What about transmission fluid...will it leak out on you too....

Also, so far I have heard three different advices:

1. Remove T-Case first, then Engine and Transmission as a unit

2. Remove Engine first, then transmission and T-Case as a unit

3. Remove T-Case first, then transmission, then engine

I guess there is no one correct answer, but I have this thing solo....so I have to figure how to do it by myself.

:doah:
 
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I would do number 3 if you're by yourself. Or even with a friend/co-helper, its much easier on everyone involved by doing one at a time. That translates into retaining all your digits. I remember a guy taking out a tranny once and it fell off the jack and pinched his fingers on the floor. The impact severed two fingers and he had to remove them permanently.

Do number 3 with a friend and everyone gets to keep their fingers.
 
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