np203 removal

[werewolfx13]

After finding most certain grave news about my th350's status, I'm going to rebuild it. Okie, no problem..except I can't tell how the np203 case is bolted to the transmission. A hardened, half inch thick layer of grease and dirt has obscured everything, and I can't for the life of me see any trace of where the two mate. Also, I can't fully tell how the shifter is attached to the case, or if the shifter can be left on the case and the whole thing lowered once separated from the transmission. I did some searching, but nothing that seemed to shed much light. If anyone has any pics, comments, tips, or advice I would very much appreciate anything I can get. I intend to clean the exterior and replace the seals in the case when I have it out, is there anything else I should do to it while I've got the two out and apart? I'm keeping it full time.

[74k20]

I'll try and give a few pointers.  My 1st experience of removing the 203 was out of a donor k10.  I used a large floor jack and had a rather un-controlled fall (almost crushing my hand), but I got it out.  The 2nd time was when the trans went out in my k20 and I swapped in another used th350 (from the same donor k10).  This time it was a more controlled fall since knowing what to expect.  I got smarter during re-install, which I'll explain later.

WARNING, this was the BIGGEST MESSIEST job I've EVER had to deal with in auto wrenching.  From cleaning all the grease crap to find the bolts, to all the spills that seemed to leak ALL over the ground ALL over the place, EVERY time I even touched or moved the t-case or trans.  May just be my bad luck however.

1st off drain fluids from trans and t-case if possible.  By removing the bottom bolt on the t-case where the nose cone is, will drain most of the oil out of the t-case (motor oil NOT thick gear oil).  Removed front and rear drivelines.  My 74 had a side mount to the frame, but the donor 77 did not.  I also loosened and moved the e-brake cable from being in my way.

I've attached a picture of the bolt pattern that mates the 203 to the trans.  Picture is not correctly orientated as it's my spare sitting in my garage.  The top bolts will take some hand twisting or right combination of extensions/knuckles ect.  I don't think I completely took off the shifter on this extra 203, but I did remove it during my trans swap since it was easy.  It can be accessed via inside the cab by removing the shifter cover.

The huge pain is that there is NO flat surface to hold up and use a floor jack.  it's totally off center and will EASILY fall, and it VERY HEAVY.  Please use caution for safety sake.

Now to install I got a "little" smarter.  I actually spent a bit of time to build a cradle for the 203 to sit in, then tack welded that to my floor jack for stability during lifting into place.  This did create a tad problem as it was now too tall to slide under my truck.  Solved that by quickly lifting up the truck to slide it under (redneck).  Re-install was SOOOO much easier using the cradle, it was actually easy.

I'm SURE there are several steps I missed, but it's not that hard.  Have LOTS of rags, oil spill material, ect for all the messes that will be made. 

[werewolfx13]

Very good info, I've got two 250' rolls of pigskin, hopefully that will be enough at something like 1 sq ft will absorb a little over 1 qt of oil.
I'll enlist some extra hands too, and see what I can do for a cradle for my jack. My jack might be about useless, however, as I'm working on a gravel/mud driveway complete with puddles, pits, and a big ridge in the center.

[74k20]

Extra hands may only be nice if you get crushed, ha-ha.  Or while trying to drag that heavy iron out from under the truck.  It's an awkward job while laying on the ground.  Don't want too may people under in your way, as you might want an escape route while it falls. It's WAY to heavy to do a chest catch without a couple broken ribs, at least for a small guy like me.  Mainly just awkward to grab or hang onto, while being a greasy mess.  Stack up some boards so it at least doesn't fall all the way down.

If you have the means to fab up a cradle, it's VERY nice to have.

[werewolfx13]

I could probably come up with something, got any pics of the one you made without the case sitting on it, or some close ups with the case on it? that would be awesome if you do, thanks for the tips so far.

[Donut]

High hump?  If so, pop it off and get access to the top of the trans.  Shifter removal, top bolts on the trans and whatnot are much easier to get to.

My tbh 350/205 was installed using an engine hoist, picking it through the hump.  Though it was easier with the hoist as I didn't have doors on or a seat in it.

[werewolfx13]

I've been thinking about removing the hump for access anyway, will have to hold the nuts from the bottom and have my wife back them out from the top. I might think about removing the seat anyway, as the cab and seat need a good cleaning with a mold killer..though I don't have a hoist, nor a driveway flat enough to be able to use one for this application anyway..

[Donut]

Before you bother the wife (you WILL pay for it later, lol) check.  Mine were tacked on, no back-up wrench needed.

[werewolfx13]

I already know mine are loose, I tried removing it when I was verifying the transfer case was going into gear correctly while diagnosing the transmission problem. The body is a 1980 c10 diesel body with a '76 k20 running gear, frame, and VIN. My uncle swapped the body in the early 90s when the '76 body was falling apart.

[Jason S]

If you're working on mud/gravel, it might be worth investing a few dollars in some 4x8 sheets of plywood or OSB.  If you wind up using either a jack or hoist the ground covering might be handy.

[werewolfx13]

That's a good idea..The gravel is actually packed tight enough to roll a jack on, at least to some degree, but the biggest problem is the crown in the middle of the driveway, and the tire ruts. I bought this house in august of 2011 and the driveway is suitable for parking, but virtually nothing else, I'm thinking about widening the driveway another car width and filling the lower points of the old driveway with an extra rock-heavy concrete mix. In the meantime,  if it feels like it will be a problem, I'll pilfer a few of the drive boards my dad uses for his crane and bucket truck for tree work in yards. Each section is about 1.5" thick, 2'x8' with rope handles for dragging.

[Jason S]

So werewolfx13, did you get the t-case and transmission out?

[werewolfx13]

Haven't had the time yet,  I've still got to mock up a cradle out of wood so I can go dig my stick welder out of storage in the back of my parents storage garage and replicate it. My 110v flux core wire welder hasn't been known for creating the most reliable welds the last few times I've used it, and I trust the welds I achieve with my 220v 1950's era Marquette stick welder, but I don't have a means of sheltering it at my house.

[bake74]

Haven't had the time yet,  I've still got to mock up a cradle out of wood so I can go dig my stick welder out of storage in the back of my parents storage garage and replicate it. My 110v flux core wire welder hasn't been known for creating the most reliable welds the last few times I've used it, and I trust the welds I achieve with my 220v 1950's era Marquette stick welder, but I don't have a means of sheltering it at my house.

     Agreed, I would not trust a 110v flux core welder with this chore unless you make several passes with it, the penetration is not the best with those.

[werewolfx13]

Talked to a friend of mine today, and he suggested dropping the trans and tcase together with a motorcycle jack. Its what he did to remove his transmission and tcase in his 74..any idea why that wouldn't work? he offered to let me use his cycle jack, and that would save me a day of mock up/final build for a cradle for the tcase, and splitting the two would be a lot easier on the ground where I can see what I'm doing..