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Old 06-14-2011, 11:19 PM   #1
jbclassix
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NP 205 Rebuild and Info

I'm posting this here in hopes that it helps out others. I am hoping this can be a resource for the mighty New Process 205. I am rebuilding a vintage 1970 NP 205 for my Suburban. I would say this is a "first gen" 205, since my 69 has the Rockwell T221. If anyone has any info to add, please go right ahead. Also if anyone sees anything I did wrong, let me know and I will correct it so I am not spreading bad info. I don't have all the spline counts for all the different 205's so someone else will have to add that.
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Old 06-14-2011, 11:32 PM   #2
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Re: NP 205 Rebuild and Info

First I removed my rear output yoke. This is my home-made yoke holding fixture that has come in VERY handy over the years!



With the t-case in 4-hi I also removed the front yoke while holding the rear yoke.



Remove the speedo drive assembly



Remove the rear seal housing



The rear output bearing just slides off. It is "sandwiched between the yoke and speedo gear



Remove the speedo drive gear



Remove the spacer from behind the speedo gear



Remove the rear bearing housing. Be careful removing the housing, the front bearing is a needle type and they will fall out.



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Old 06-14-2011, 11:52 PM   #3
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Re: NP 205 Rebuild and Info

Next the Rear output shaft can be removed. There are roller bearings inside the output shaft assembly. They have a snap ring to keep them in place, but still use caution not to lose them.



Next I removed the front output seal housing



Next I pulled the front output bearing. There is a spacer/oil slinger behind the bearing.





Next I removed the rear bearing cover for the front output. There are more needle bearings so make sure you have all of them.





Next I pulled the front output shaft assembly. The shift collar and high gear stay in for now.



Next the shift collar and high gear come out. I reassembled the whole front output assembly to keep everything together.





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Old 06-15-2011, 12:08 AM   #4
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Re: NP 205 Rebuild and Info

The next part I had to dig for. To remove the shift forks, there are 2 expansion plugs on top of the case. Using a punch I drove them into the case. Under each plug, with the t-case in the neutral position, the roll pins for the forks can be driven out of the shift shafts.







Next I removed the shift bar, marking what direction it came off. I like these shift shafts. The ones on my 79 K5 had a longer 2-4 shaft with a boot-shaped shift bar.



More digging. There are two detent ball assemblies that need to come out.



The shafts can only come out if they are in the Neutral position because of the interlock pins. I put them back together so I could remember how they came out. This one is the Hi-N-Lo fork, the upper one.



This is the 2-4 fork. This is the lower one.



Next I removed the PTO plate. My case still had the original ID tag on it so it will go back on.





Next I removed the interlock pins. There is one in the front of the case and one in the rear of the case. I marked them so I would know where they came from.



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Last edited by jbclassix; 06-15-2011 at 12:25 AM. Reason: added image
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Old 06-15-2011, 12:14 AM   #5
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Re: NP 205 Rebuild and Info

Next I removed the snap ring that holds the input bearing on the input shaft. This one is the 27 spline type that mates to the TH350.



Next I removed the front bearing and pulled the input shaft out. I could not get the input shaft out without first removing the shift fork.

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Old 06-15-2011, 12:23 AM   #6
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Re: NP 205 Rebuild and Info

Next I removed the nut and washer on the front of the idler shaft.



Next I removed the idler shaft cover on the rear of the case. This is NOT what it should look like! The idler shaft lock-nut had come loose and the shaft had been spinning against the cover. This could have caused sever damage if it had not been cought.



A few taps with a soft face hammer sends the shaft out the back. Be very careful not to damage the threads!



The idler gear assembly will now drop down and out of the case. Be careful not to loose the bearings, spacer, and shims. Once again I put everything back together so I would remember how it goes back in.





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Old 06-15-2011, 12:36 AM   #7
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Re: NP 205 Rebuild and Info

This needs a sticky!
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Old 06-15-2011, 02:02 PM   #8
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Re: NP 205 Rebuild and Info

jbclassix,
You just made my life a lot easier, as I'm just about to crack into my NP205 from my 72 Blazer. Great info and detail on here, awesome job. Quick question, were did you get your parts and seals? Keep it going the pics are great.
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Old 06-15-2011, 02:15 PM   #9
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Re: NP 205 Rebuild and Info

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jbclassix,
You just made my life a lot easier, as I'm just about to crack into my NP205 from my 72 Blazer. Great info and detail on here, awesome job. Quick question, were did you get your parts and seals? Keep it going the pics are great.
eBay... they were pretty cheap
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Old 06-15-2011, 02:45 PM   #10
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Re: NP 205 Rebuild and Info

I am out of cam lube, so an old trick I am using this time is Petroleum Jelly to hold the rollers in place. Then with a new gasket I installed the rear bearing housing. Since none of the bolt holes are blind on the 205 I used thread sealant on ALL the bolts. Torque for the housing bolts are 30lbft





Next install the spacer, speedometer drive gear and rear bearing with a perimeter snap ring. You should be able to look down the speedometer adapeter hole and see the gear. Here you will also notice that the gear spins freely on the shaft. Once the yoke is installed and torqued, the gear, and spacer will be captured between the bearing and the shoulder on the shaft. This will also locate the output shaft to the rear which is why there is no thrust bearing between the input shaft and the output shaft











Next I installed the rear output seal in the seal housing. My rebuild kit came with several seals so I sized mine to the output yoke. It didn't take much force to set the seal at all. I am holding the housing in the orientation it goes on the case. You will notice the oil passage by my pinky finger. This has to line up with the hole on the case and cannot be covered by the gasket. The bolt holes are spaced differently so it's hard to get it wrong. Torque on these bolts is 30 lbft. Again use sealant on the threads. I did not find any specs on depth of the seal so I installed it flush.





I'm showing this picture without the seal housing for reference. At this point you should be able to pull the shaft back against the bearing

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Old 06-15-2011, 03:29 PM   #11
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Re: NP 205 Rebuild and Info

Rebuilding the front output is next



To make things easy, I removed High gear and the shift collar, cleaned them, and installed them in the case.









Next the front output comes apart very much like the rear output. Snap ring comes off, index washer comes off, pin comes out, and Low gear drops off the shaft. There were not thrust washers on the front output.





Once everything was clean I started putting it back together. I used Petroleum Jelly on the rollers to stick them to the shaft



For no reason, this time I set Low gear on the shaft, then installed the divider ring, then the second row of rollers.







Next the pin, then the indexing washer, then the snap ring







Next I installed the front output shaft in the case, feeding it through the shift collar and the High gear







Next I installed the thrust/slinger washer and the bearing with a perimeter snap ring. Sorry I forgot to take a picture of the bearing



For the front seal retainer my thumb is pointing to the oil passage that needs to line up with the notch in the gasket and the hole in the t-case. Here is the part I am not sure I did 100% right. The front seal has dual lips and the metal side is supposed to go on the inside. Well, both sides are metal, and there is a spring on both sides, so this is the way I installed it. Anyone wanna ensure this is correct?





I installed the seal housing with a new gasket, installed the bolts with sealant on the threads, and torqued the to 35lbft... I don't know why these are higher.



Next I used Petroleum Jelly to install the rear rollers



Then I installed the rear cover with a new gasket and sealant on the bolt threads. Torque is 30lbft

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Old 06-15-2011, 03:54 PM   #12
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Re: NP 205 Rebuild and Info

Next I installed the detent balls with the shift rails in Neutral, then the springs and then the caps. I don't have a torque spec for these







Then I installed the expansion plugs with a little sealant on them.



Next I installed the shift bar. Notice that on this type of linkage, the slotted hole goes to the 2-4 rail, and the holes are to the rear



Next I installed the linkage



Then the PTO cover with gasket and bolts. I don't have a torque spec, but the threads do need sealant



Then the speedo drive shaft and adapter. I don't have a torque for this



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Old 06-15-2011, 10:47 PM   #13
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Re: NP 205 Rebuild and Info

Thanks for taking the time to post this. It will be very helpfull for my up comming rebuild... Bill
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Old 06-15-2011, 10:56 PM   #14
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Re: NP 205 Rebuild and Info

This is great, will definitely use your work in this thread as I do my NP205. Was the primer rustolium red primer? Do you plan to put a clear over the primer to seal it? That was my train of thought as I was wondering about paint.
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Old 06-15-2011, 11:10 PM   #15
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Re: NP 205 Rebuild and Info

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This is great, will definitely use your work in this thread as I do my NP205. Was the primer rustolium red primer? Do you plan to put a clear over the primer to seal it? That was my train of thought as I was wondering about paint.
Yeah, the primer was just rustolium red... a matte clear would be a good idea for sure! I may do that!
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Old 06-11-2013, 06:38 PM   #16
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Re: NP 205 Rebuild and Info

its been a while...but this is a super quality thread...lots of work went into it!

I am not exctly up to par on the level required to do this...but I just got a rebuild kit for my local shop that is familiar with such.

it was very informative to actually see whats going on...

I can do most on my 67 CST...but we all have our limitations...
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Old 12-28-2015, 05:49 PM   #17
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Re: NP 205 Rebuild and Info

This looks like an excellent guide to rebuilding your NP205. The only thing I might do differently is, wait till you get the entire thing back together, then mask off the little stuff, then paint it, thereby protecting everything including the hardware and covers.
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Old 01-01-2016, 12:02 AM   #18
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Re: NP 205 Rebuild and Info

Great info!! Just a couple of questions:
Are you suppose to apply rtv to any of the gaskets?
Does anyone have the correct needle bearing counts for each bearing?
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Old 06-15-2011, 11:22 PM   #19
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Re: NP 205 Rebuild and Info

This was seriously one of the best NP205 write-ups I've ever seen. Excellent job jbclassix!
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Old 06-30-2011, 06:12 PM   #20
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Re: NP 205 Rebuild and Info

When I tear mine apart again, i'll be sure to scoot over Redwood Rd and drop mine off! Great job!
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Old 06-30-2011, 06:43 PM   #21
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Re: NP 205 Rebuild and Info

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When I tear mine apart again, i'll be sure to scoot over Redwood Rd and drop mine off! Great job!
Did you pick Redwood road randomly? I live about 100 feet off of Redwood
I will be dropping my drivetrain into the Blazer Sunday if you wanted to come by.
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Old 07-08-2011, 03:32 PM   #22
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Re: NP 205 Rebuild and Info

Any update on the linkage JBC?
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Old 07-08-2011, 08:42 PM   #23
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Re: NP 205 Rebuild and Info

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Any update on the linkage JBC?
Unfortunately, no... I have not done any work on it. I have been working on an Eaton HO72, the 4th door project, and work. I think the wave washer goes on the shift lever. I have some time so I will check tonight!
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Old 07-08-2011, 09:00 PM   #24
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Re: NP 205 Rebuild and Info

OK, so I looked up where the wave washer goes, and if you have the round-bar linkage, the linkage goes on the shift lever, then the wave washer goes against the lever, then the flat washer, then the cotter key. I will see if I can link the adobe picture.
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Old 06-30-2011, 06:17 PM   #25
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Re: NP 205 Rebuild and Info

That previous post was for SeventyOne, JB this is a great post and thanks for all the pics!
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