NP203 removal and rebuild

[Chris64]

I couldn't find anyone discussing this. It will probably be a whole series of questions because, of course, I've never done this, but what could possibly go wrong?

I'm pulling an NP203 from a AT350 transmission. I started this evening draining it(about 2 quarts) and removing the drive shafts which went mostly smooth. The little bearing cap on the rear holding the needle bearings did come off. A few needles fell out. I'm pretty sure I found them all but they might've picked up dirt. I planned to just parts clean them and repack with new grease. Is that fine or should I replace? It looks fine.

Next will be to remove the transfer case. I count 7 bolts holding it on which some will be really rough to reach. I was going to buy a HF trans jack since I'm doing this solo and for $79 seems easier than rigging something with 2x4's. Plus I could always use it in the future.

I'm trying to cure a pretty bad leak. Most of it seems like it's leaking from the speedo shaft output. I just bought a gasket and seal kit so hopefully that will do it.

While I was down there I noticed a serious crack on the flywheel cover right next to the starter. Initially I though it was part of the transmission but this seems like no biggie...or is it?

Anyway. I'll try to post pics or video if I can.

 

[xm20k]

If it has braces bolted to it to help stabilize the transfer case it could be an issue, others my have to chime in my experience with two 4x4 trucks both had a divorced setup ie. a drive shaft between the transmission and transfer case.

 

[Chris64]

If it has braces bolted to it to help stabilize the transfer case it could be an issue, others my have to chime in my experience with two 4x4 trucks both had a divorced setup ie. a drive shaft between the transmission and transfer case.

I don't think it has any braces on it. There's a big cross brace mounted to the back of the transmission and this appears to be just appears to be mounted to that. I'm working up the desire to get my hands dirty this morning. I should know more soon.

 

[Grit dog]

Been a while….like 35 years almost but I don’t recall anything tricky about it. Yarded a 203 out of a truck in a field and replaced the busted one in a garage. 2 people no jack, basic hand tools.

 

[Broken85]

Pull the 7 bolts off the trans-adapter after the crossmember. The bolts aren’t really hard to get to. 3/8 socket. The bolts are metric. I think they are 14mm. I usually use a transjack to pull them down, but strap it in before you pull it. they don’t sit nice in the cradle once it’s free. The weight will make it want to rotate to the driver side and flip off the jack.

I usually just bench press it back up there and get it on the splines and then get a bolt started quick. It is tough to get it clocked right on a trans-jack because the chain housing is the lowest point. Maybe you could get it blocked on their some how, but I don’t have the patience. it probably only weighs about 80lbs give or take.

 

[Chris64]

OK well it went about as expected - in that I think I'm doing something wrong.

I took out the 7 bolts where I thought it started. Then I realized I wasn't removing the blocky part where the shift linkage connects to the transfer case. Oops.

I looked online and saw someone else's 203 - these appear to be the correct bolts. I'm all out of sunlight - this will have to wait until tomorrow.

These are way easier to reach than the ones I took out

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[dragstews]

If it has braces bolted to it to help stabilize the transfer case it could be an issue, others my have to chime in my experience with two 4x4 trucks both had a divorced setup ie. a drive shaft between the transmission and transfer case.

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Are you refusing to the strut rod that bolts to one bell housing bolt ?

 

[Chris64]

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Are you refusing to the strut rod that bolts to one bell housing bolt ?

I don't know what this means.

 

[Broken85]

The think that strut is for an NP208

 

[dragstews]

I don't know what this means.

Sorry ... My spelling sucks !

"Are you referring to"

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[xm20k]

He stated the shield was cracked by the starter and asked if it was an issue this is what I'm referring too with my statement that some shields are cast and have braces to stiffen the trans at the bell when a transfer case is hung off the end it then has support rods to the cross member I believe. Like I said no personal experience with the 4x4 setups in these trucks as mine were all 2x and the only 4Xs I've owned were not mounted to the trans but to there own crossmember with a drive shaft in between. So not sure on what years etc. these were used on and was just noting that if they are in use the cracked shield could be an issue in the future.

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[dragstews]

Oh I see now ...

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These are the factory support rods I'm using on a 4L85E trans.

 

[Chris64]

Ahh - it looks liked stamped steel. I don't think it's a big deal although I will replace. At first I thought it was part of the trans block. I didn't get any pics of it - I'll post some up tomorrow.

 

[xm20k]

Yes this

Oh I see now ...

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These are the factory support rods I'm using on a 4L85E trans.

Yes this!

 

[Broken85]

Ahh - it looks liked stamped steel. I don't think it's a big deal although I will replace. At first I thought it was part of the trans block. I didn't get any pics of it - I'll post some up tomorrow.

They are actually casted aluminum. They came on the K series trucks. They are hard to get after market. It’s there for additional structural support. It has nothing to do with the starter besides being at the same place at the same time.