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NP205 failures?

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Who had had them? What caused them?

The other day I was driving my 1990 K5 down a gravel road. I came to a stop sign, stopped, and then accelerated away. As I was getting up to speed a noise developed suddenly. I let out of the throttle, and turned the radio off to listen, and before I had a chance, my rear axle locked up. It brought me to a pretty quick, hard to control stop. I got out and looked things over. No obvious signs of breakage. I tried to drive it back and forth. Nothing, would kill the engine the second I let the clutch out. I locked in the front hubs, shifted the front axle into gear, and shifted the rear axle into neutral. I could move. Kind of. It drug the back tires pretty hard. So I called the buddy I was headed over to help. He picked me up, we went to his place and got the head off of his 3020. Then we went and borrowed another buddy's wrecker and towed it to his shop.

We dropped it off, and I let it sit there for a few days. Monday morning I went over and unbolted the axle flanges. Drove it into his shop and onto a hoist. Pulled the inspection cover on the 14 bolt. Looked good inside. Then I pulled the rear driveshaft. It wouldn't turn. The output of the transfer case was seized. I pulled the PTO cover off and looked inside. It looked fine inside. So I pulled the rear yoke, the rear seal housing, and when I tried to pull the speedometer housing off the back of the NP205, it was stuck. Took a couple pry bars, but I got the housing off. It brought the rear output shaft and gear with it.

I got the rear output shaft out of the speedometer housing (it took a big swing press). The smaller needle bearing that presses into the speedometer housing had disintegrated, and locked up the shaft. I ordered a new bearing, but then I found one locally. I took a different speedometer housing and output shaft from a "parts" NP205 I had. Installed the new bearing and put it back together. It is working fine.

Nothing else looked bad inside of the NP205. Is this a common failure? Has anyone else had problems with this? There was gear lube in the transfer case (it was very cold when this happened). The NP205 is part of a doubler, and it is clocked up 2". This means you can't put as much gear lube in it as you could if it was in the factory orientation.

I ordered a PTO cover from ORD with a fill plug. I was thinking about over filling the NP205 a little. Thoughts?

Martin
 
clocked 205 = new fill plug setup def.

some get bling bling covers with plug like i did for mine others add a 90* elbo to the fill hole to let it over fill this way also.

search 205 and doubler oil should come up with pics.

pic bling cover from nwf for front output area with fill plug for this.

32 spline 205 reman 098.jpg
 
I already have a PTO cover with a fill port coming from ORD.

Martin
 
I once broke a 27 spline input and TH350/NP205 adapter on my old 73. I was going to a transition from dirt to pavement and stood on it. Heard a load bang and went nowhere. Towed it back to the house and pulled the transfer case and discovered the input twisted at the O-ring groove. The shock of the input breaking must had cause the drive-train to twist therefor breaking the adapter. It probably didn't help I was running poly transmission mounts and rubber motor mounts. I just rebuilt the transfer case so the adapter one piece when I installed it.

Amazing, I swapped the distributor the night before and accidentally had switched two plug wires.

The motor was 383.
 
I've know many people that beat the snot out of their 205's with no issue. I just recently installed a doubler with the 2"up rotation. I put my driver tires on 10"tall car ramps. get the 205 in the 'stock rotation'. then i can fill with the correct amount of fluid. have not put many miles on it yet......so hopefully don't have a simular issue.
 

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