Rebuilding an NP202

[Gunfighter97]

I will be doing a full rebuild on this unit, its already removed, and is factory original to the truck it was pulled from(1965 1100). Leaks like a civil servant, and possibly has bearing noise(its either the drivelines or these bearings). The first step is to ensure there actually is a transfer case somewhere encased in this glob of road grime:

The gunk is strong in this one... Here it is after some screwdriver scrubbing:

Here is the oil that came out of it, not the greatest ever, but couldve been nothing in there so I'll take it:

I've found evidence of both red and black paint under the grime, with some careful scratching I could tell the red was underneath the black and looks to be in a similar condition to the paint on this trucks 304 engine, so that will be the color of the new paint:

On that note, I'm a knownothing in regards to under body painting, nor do I have a spray gun, anybody out there who knows a good/cheapish DIY method feel free to educate me cheapish said, I want to do it right; I dont want to skimp anything and it needs to be durable. I have a kit on the way with seals, bearings, and small parts, I will be fabricating a couple gaskets not included in the kit and will likely need to fabricate the bearing retainer gaskets in their correct thicknesses as well. Right now I'm just waiting on a muscle bound minion to help me pick this dadgum heavy thing up and get it on a bench, and the rebuild kit itself.
Edit: just for the record, the history I've been told on this truck is that it was owned by a telephone company for line maintenance, and heavy use of a pto winch. So consequently its high hours, but relatively low miles at around 45k

 

[Gunfighter97]

Lol just noticed most of the above pics are broken. *FIXED
Back from the holidays, with an update on this project. My removal method was sketchy at best, and haphazardous at worst so I will let you assume the much improved reverse of install is a good way to remove it. Where I'm currently at isnt too much better than where I left off, I'm trying to find a 1 5/16" socket that will fit inside the drive yokes. Here it is 90% clean atleast:

Gunk removal consisted of a worn out wire wheel, cordless drill and a butt ton of drill batteries. Works exceedingly well. Note the brownish powder eveywhere:

One note on this method, avoid the alluminum flange on the output shaft, the wire erodes it very easily. With a little research here and on Binder Planet I found out that these units left the NP factory with a red oxide primer/rust prevention type paint, and were sprayed black as a sub assembly at the IH factory. I will be using red oxide enamel based paint as the under coat of all the cast parts, then painting it IH red. I'm going with the red because its much easier to spot leaks, and it will look nicer when its clean.(AND IT MATCHES THE ENGINE/TRANS BECAUSE OCD) I may use a bit of black paint here and there, but probably only for limited aplications where leaks cant start. Luckily for me and my imaginary/non existent spray gun, both the red oxide and IH red enamel were available in rattle cans from my local Tractor Supply Co, a format I'm extremely experienced with. I can personally attest to the fact that you can indeed get uber high quality mirror like finish with the right technique using rattle cans, not that it matters too much on this type of part. I've heard people say otherwise, but its a myth because I've done it before.
*also, mods feel free to insert a shameless IHPA add here if you stock these paints as well, I just havent had time to make it back up to Grass Valley yet.
This truck is (the story goes) low milage, high hours, and though it probably doesnt need bearings, due to the wear in the drive shafts, I'm replacing them anyways. The kit is from Torque King 4x4, and includes the pto gasket even though it says that it does not on their website. I can't remember wich one it was, but I did inquire about the manufacturer of the bearings, and they are one of the higher end Japanese makes. In my case the low gear rollers are refurbished NOS due to the current availability.
Here is the kit:

The shaft seals are good quality, however they are not the original type. The original seals are 0.5 thick and have rubber on the inside to keep oil in and felt on the outside to keep dirt out. I'm in contact with a member of Binder Planet who came up with a way to replicate this, and will post up a link/more about it later on with his permission(his idea not mine, if he does a write up I will post a link to it here once my new seals come into play). More to come soon on this one, I just need to find the right socket.

 

[ihpartsjeff]

Just find a socket you don't care much about and grind/sand/turn it down to where it fits. If you don't have a lathe, grinding it on a bench grinder or belt sander while you turn the socket until you get it to where it will fit the yoke.

 

[Gunfighter97]

THE HAAAUUULKKK
RRRRRAAAAAAAAWWWWWWWRRRR
FINALLY the dive yoke nuts just came off and I can start on the fun part of this project. Giant impact driver for the win!
*Note to Jeff's coment: that was one of my ideas but a socket from napa ended up fitting perfectly.

Awlrighty, step one as you could probably figure out, remove the cotter pins/castle nuts from the yokes. Once their off, the yokes slide right off the shafts. This produces a weird smell that I can only describe as somewhere between camp fire and bad bacon. I didn't have my instructions for disassembly with me today so I only went as far as I could remember. With the three yokes removed, I took a minute to remove some other unnecessary external parts, such as the remaining parts of the linkage and the mounting bolts I put back in to keep dirt and water out. The first big step is to remove the 8 bolts (two are nuts on studs) and pull the rear output shaft assembly. E.G. the big hunk on the left:

*Important note: I DID THIS WRONG! Before removal, install the yoke and screw on the castle nut. I poped the housing loose by tapping on a lip that overhung the edge of the case, however because I already removed the nut/yoke, the shaft stayed in the case and needle bearings went everywhere inside the assembly. Not a huge deal, the parts inside misaligned so I didnt see the order they were in, but I was able to figure it out. Here you can see the rear shaft and assembly, note the small pile of rollers came from the back side of the big drive gear, integral to the shaft:

These thinner rollers were the ones that fell out, I found them as I disassembled the housing:

The alluminum flange with the seal comes off first, I'm not confident this had the original seal, the road grime wasnt as strongly stuck here as elsewhere, nor was it the proper thickness to be fully seated in the alluminum flange:

Next up, a small ring is removed and the main bearing is pulled:

Once this bearing is removed, the spacer and worm gear for the speedo drive can be lifted out, and here I found the rest of the needle bearings:

I removed the breather vent, 7/16 size, mine will need to be taken apart and cleaned or replaced:

The last thing to remove with acception of the speedo drive(didnt have the right socket with me) is the roller bearing cup where all the loose rollers originated from. Worth noting, this was significantly more difficult to remove than the main bearing:

Last thing I did today was remove the pto cover for some pictures:

On the inside of the housing the finish is very nice, all I'm going to do with the case itself is degrease once its bear, tape up all seal/mounting surfaces and paint the outside. Final note, my rear yoke is broken, so I will be sourcing a new one, more to come on that. Also sorry the pics are dark, I'm working in the barn for this and forgot to turn on the flash for some of em.

 

[ihpartsjeff]

Nice write up and puller set! Good to know on the Napa socket.

The reason the smaller needle bearings fell out was due to that bearing being worn out.

Now back to your rebuild.

 

[Gunfighter97]

Jeff, remind me later if I forget, I'll post up info on the tools I used. Believe it or not that puller is Harbor Freight, nicest thing I've ever got from them by far. I was wondering about that bearing since its one piece in my kit.

 

[Gunfighter97]

Update for the last bit of tech, this is usually done along with the above before moving on but I didnt have the tool with me.

Removed the speedometer drive from the housing(15/16) it poped loose with a breaker bar and a size 13 boot standing on it.

To remove the input shaft assembly, the first step is to remove the detint assembly for the shifter bar. This broke loose easily and revealed the spring and ball. These will be replaced, the springs are known to break, and the balls obviously wear, neither one look bad but best to use new components anyways:

The next step is to remove the roll pin that secures the shift fork to the shift bar, the instructions say to work through the hole where the rear output assembly was. This is physically impossible because of the extream angle of the punch or 5/16 bar relative to the hole. With the shift bar fully foreward I used a roll punch and a rachet extension to drive out the pin straight through via pto port:

Unfortunately I didn't figure this out initially and spent about 2 agrivating hours smashing my fingers every other attempt or so and with various roll pin punches being trolled by a roll pin (troll pin?) that apeared cemented in place with no good way to drive/drill it out. Uppon first aplication of my extended punch meathod the pin drove straight through, all the way, with one firm swing like it had just been freshly installed. Once the troll pin was out(doesnt come fully out, stops against the case) the bar can be pulled out the front and the input shaft can be slid rearward through the gears out of the main bearing and the cluster dropped into the case for the fork to be lifted up and out. Once again, this can be done(maybe) without rollers going everywhere.... Good for you if you manage it mine didnt come out in one piece. Theres currently around 10-20 rollers submerged in the excess oil at the bottom of the case. Also my phone died while I was removing the troll pin so I will have to grab more pics for an update on these steps. The shaft assembly comes out through the rear output hole, and leaves the pto drive gear behind to come out through the pto port. All the remaining components simply slide off the shaft. At this point I would be removing the input bearing retainer, followed by pulling/inspecting the main bearing and seal, but I havent done that yet because I ran out of time I'm going to enjoy hammering that roll pin flat later. . . .

 

[Gunfighter97]

Pics of the input components, here is the shaft, drive gear, shift fork, shift bar, and a couple things I forgot the names of

Here we see the PTO drive gear, it lives all the way foreward on the shaft as seen in the second pic through the pto port:

And here the void in the case behind the input main bearing:

Refer to reassembly for the complete input cluster assembly(sorry, phone died before I could get more pics)
Next up, off with the bearing retainer, four simple nuts and a light tap on the edge with a screw driver to pop it off:

Then the bearing is pulled and inspected. Worth noting, this one had the least feelable play in it, it was still quite tight. Also, this one did not want to come easy, and made an audible snap as it broke loose:

This completes the input shaft assembly removal. Stand by for foreward output disassembly...

 

[Gunfighter97]

Forward output shaft disassembly, easier than you think!
Start by unbolting the rear bearing retainer (tech note/ this was the first evedence I noticed of thread sealant of any kind) and taping lightly on the front of the shaft untill the bearing retainer's shoulder comes out:

The rear bearing retainer is then simply pulled off the shaft, once again, the captured roller bearing immediately fell apart:

Then the gear/shaft comes out in one pice (carefull, its about 40% of the entire weight of the whole t-case):

Next up, same bearing retainer business as the input shaft, this bearing was tight, not as much as the input. It came out little resistance, I put the puller on and tightened the collar by hand to seat it when I noticed it was just sliding right out:

This was by far the easiest part of this whole process. Stand by formore...

 

[Gunfighter97]

Idler shaft/gear/shifty thingy:
Roll pin number two comes next, I pushed the shifter bar all the way forward and drove it out through the pto port, the shift bar can then be pulled straight out and the fork rotated and removed:

The poppet ball will be loose in the bore once the bar is pulled, I simply rolled it out into my waiting hand by tipping the case, the spring and shift bar interlock pin are not so eailly removed:

The interlock pin stays put due to residual goop, I lifted the spring upward with a standard driver and used it to push the pin upward and held it there with a stubby driver. This allowed the end of the pin to protrude upward into the upper shift bar bore, where I lifted it out with a finger and reeeeeaally long thin driver from the other side. I just scooted it up till it misaligned and picked it out through the cap screw hole with a magnet. The spring simply came out of the bore when I removed the stubby driver:

From here we remove roll pin #3 from the idler shaft, I chose to go at it from a weird angle just because the end was inside the hole and there was no chance of mushrooming it:

Once the pin is out, the shaft is simply pushed through the case with light tapping, and pulled out. The gear assembly is then lifted out through the rear output opening:

The assembly can be removed in one piece. . . again. . . good luck with that. Mine came out as you see here:

The sliding gear assembly is seperated by first removing the snap ring and application of a couple wood blocks and a rubber mallet. Note no rollers inside, I thought there were, in that regard it may not be worth the effort to take this apart:

that is the final step for disassembly. The stripped case weighs by my guess roughly 35-45 lbs so its much easier to manipulate for draining the remaining oil/roller bearings/dirt as well as for paint and prep.

 

[Gunfighter97]

And I was wrong. . . about the last step thing, the seals still need to be removed, along with the body of the bearing assembly from the forward output shaft rear bearing retainer. . . woohoo thats a mouthfull, reminds me of my days at North Mid Valley South Middle School
Anyways, the bearing assembly body is straight forward enough, presses right out:

The two forward main seals are removed by applying pressure via press to the inside face on one side untill it begins to deform, then relase and rotate slightly, repeating untill it starts to press out. The seal looks like this when it works:

When the face deforms without breaking loose, the press arbor slips off. When this happed on the second seal, I resorted to a brass punch and 10oz ballpein. Then the end of my punch deformed so I switched to a hardedned steel punch. Then I steped up the hammer size to a 18oz crosspein. Then I got angry and the punch punched a hole or three but it finally came out here is what the seal looks like when you didn't remove it properly:

The rear output seal has been replaced with a modern type seal that lacks the felt and 0.5" thickness of the original two. I already figured it was a modern replacement without even looking at it. The rear yoke with its evedence of having blown off a u-joint at some point:

and the fact that the nut was 5x tighter than the others were evedence enough of yet another round of PO's botched and utterly #@×%ed up tinkering. That seal simply pressed out with a brass punch:

 

[Gunfighter97]

Last bit here before paint prep starts(will update the post above with the sliding gear assy when I press it apart tomorow). The unit is now fully disassembled, the last bit went as follows:
Shift bar seals come out easy with a box end wrench(IF you dont plan on reusing them):

The bearing puller I used:

I forgot to get a pic of the socket I used on the drive yoke nuts, the brand is Carlile I think, 1 5/16, got it off the wall at napa.
*Carlyle SD12042 1/2" drive 6 point*
Note to the "average dude" looking to do this. Do it at your own risk, I'm not a pro by any standard. Know your limitations, but dont be afraid to try. I personally have a knack for making piles of parts out of mechanisms and putting them back with no instructions. Basically, I can figure the order and proper placement of parts just out of practice and simple observance. If you can do that great, if not, have a friend take pictures of the parts as they come out for assembly purposes. Pics are your best friend here, even in addition to the service manual. Short of a buddy to help me remove this from the vehicle, and pick it up onto the bench, I've done ALL of this BY MYSELF and with my own two hands; no camera man (my cell phone got verry oilly in the process). Outside of what I consider to be the "average guy's" toolbox and apart from the shop press, I have the afore mentioned socket, a few roll pin punches(pictured below, I've had a set of these for gunsmithing although I've never used these big ones before) the bearing puller, snap ring pliers, and the impact driver I used. I did all of this, in this space(apart from paint of course) note the two size 13s on the floor, theres room enough for maybe two people infront of this bench, and its also storing an ancient computer on the end. Hows that for cramped?:

Sorry but you'll have to turn your head a bit lol.
There is not alot of space required to do this, and dont be intimidated by all the gears, in reality the device is quite simple. Many of these parts can only go back in one way, and carefully tackling a job like this will greatly increase your understanding of how it works. Just for the record, I've never been inside a gear box of any kind before this.
The impact driver I used was a Rigid brand 18volt. Here are what I considder the odd(er) tools:

 

[Gunfighter97]

*updated an above post for the sliding gear assembly. Tbh, its almost not worth taking apart.

 

[Gunfighter97]

One eternity later. . .
Back to work on this grease blob I go, Ive been super busy the last couple months and this project hasnt progressed far. Currently there is a five gallon bucket of deisel and the smaller castings soaking in storage, today is the day I first attempt paint prep. More to come here very soon, stay tuned for the final epic battle against ancient road grime thats so bad, it might actually be alive. . . for now.

 

[Gunfighter97]

So foiled plans, and a week of pond maintenance/sunburn later I actually started paint prep. The final method was lots of wire wheel, lots of wire hand brushes, acetone wipe down till clear, tape, then FINALLY the first coat of red oxide primer. I began with the small bearing cap to start easy, and made up a mini paint booth. Heres the progression from pre removal, to relatively clean, to super clean, to primer:

 

[Gunfighter97]

First coats of paint here:

For reference I did two coats primer and plan for three coats of paint. Slow going with paint right now, figures the one time I have a shortage of cardboard I have multiple parts to paint. Progress from here will be the other retainer, the cover behind the front output cluster, the rear output cluster housing and then the main case wich will be done "very carefully" the rear retainer I'm going to leave bare alluminum, perhaps with a rough pollish just so it looks a little cleaner:

Also currently in the works is de-rusting/ painting the pto port cover.

 

[Gunfighter97]

The two front bearing retainers complete:

I've begun the process on the rear output housing, as well as the front ouput's rear retainer. Tapping off the housing was a little more complex this go round:

Painting has gone smoothly, although for lack of a big enough box I've resorted to running it outside, quickly spraying then running it back inside and setting the only box I have over it to keep dust off:

I'm planning on primering the yolks and painting them black to match my drivelines, but asside from that, the bolts and the main case are all thats left to deal with in regards to major cleaning. Today I realized I had no clue on how to effectively plaint my main case outside of my garage. Then a pile of scrap pvc fell on my head in the barn, and this monstrosity was born:

Hopefully it will prove a good makeshift paint booth, I plan on covering it all the way around with painters plastic and duct tape, and then anchoring it with tent stakes and rope. This is the only part I dont want to try and move in and out of my garage between coats of paint, so the plan is that this booth will hold up for atleast five days for five coats.
I'm not going to lie I'm nervous about how this rebuild will turn out but I just keep telling myself "amateurs built the ark, profesionals built the Titanic."

 

[Gunfighter97]

Rear output complete:

 

[Gunfighter97]

Oof. Feels like I've been on an epic journey with this thing... On to the main case! The first step was to make a safe covered area outside my garage to paint in, as this hunk is a might too heavy to be moving around with wet paint. And thus this wad of painters tape, plastic sheeting, pvc pipe and survey string was born; I call it the poor man's paint booth:

Next up for the housing was a very teadious degrease process that involved alot of steel brushes, and wire wheeling, followed by some brake cleaner, and a wipe down with acetone. Then I taped up the majority of the openings:

And moved it into position on the saw horses, supporting it with some long wood clamps I didnt care too much about(they needed wire wheeling anyways so paint didnt bother me) along with a wood block in each of the larger openings to level the case and one other block and clamp to help support the first two clamps. Once it was supported I completed tapeing around the supports:

At this point I did one more acetone wipedown, wich was mostly clean, the only grease I got was where I had been handling it between garage and booth, it all wiped clean. Last step, paint. A good respirator was used, and it stops the paint itself but not the fumes, so I limited my time in there to a couple minutes at most and not alot of breathing lol it was foggy in there by the time I was done:

Tons more to come on this, first coat of IH red is drying as I type, and the hard part is almost done. Once everything is painted it will start going back together!

 

[Gunfighter97]

Here it is done:

Onto a couple other parts for painting, namely the drive yokes. Acetone soak greatly reduces gunk. It doesnt remove: hard dirt in the casting pores, rust, and if you use used (read heavily reused through the process) acetone, it will leave a resedue of grime. Not greasy, but just general grit thats adheared enough to not blow away with compressed air. While wire brushes remove most of whats left, hard spots and hard to reach areas still remain. From here I found that a 5/8 wire wheel and a dremel tool work wonders. I went over the problem areas, dunk in clean acetone and repeated till they were as close to clean as possible(rust will still remain in small amounts). Next up I made up a batch of soda ash (cook baking soda in a pan @200* for an hour) and got out ye olde naval jelly. I followed the diredtions on that and did their recomended 10 minute set time, rinse and repeat for about 2 hours. I coat the ground heavily in soda ash before each rinse to safely neutralize the chemicals before returning them to mother nature (also wash alot of soda ash into the ground on top of it all after to be safe). Next I dunk in the clean acetone to remove water and then lastly went over the whole yoke till shinny with a new dremel wheel, then soak in the clean acetone. From there (where they are now) i will pull them out and paint. First 2 coats red oxide then 3 black to match my rebuilt drivelines. While these are in progress the two flat stamings for the shift linkage along with the crossmember mount bracket are prepped the same way and will also get black paint.
The afore mentioned bracket:

The referenced "hard spots":

The same bracket after naval jelly:

The same yoke after dremel/naval jelly: