NP203... no 4 wheel drive

[Bextreme04]

Small update here- I've been busy traveling so I dropped off the truck last week at a shop I've never been to. My main mechanic friend retired and recommended the place. They also specialize in aftermarket offroad stuff- so they liked my truck instead of laughing at it.

The chain snapped. And I had the wide chain. The 2.5" instead of the 2.0". Calling around they so far have only found new 2" chains and they are around $300.

I told them at this point even throwing a used chain in there would be fine to get it rolling again. I'm now fully planning on ordering a 4 speed Atlas transfer case for it in the next year.

I still don't understand how without any warning a chain can snap when cruising at 60 mph down the highway. Oh well. I've had a NP203 in 3 different squares back to 1990 and never had an issue until now.

Hell, for a lot less than $300 you can have a 205 and never worry about breaking it again. That atlas is stupid expensive isn't it?

 

[77 K20]

Hell, for a lot less than $300 you can have a 205 and never worry about breaking it again. That atlas is stupid expensive isn't it?

The issue I have had for a long time is both the NP203 and the 205 do not have a low enough gear reduction ratio for me. So putting in a 205 that I don't own then re-doing both driveshafts gets me to a more robust unit that still doesn't have a low enough range for me.

You can do a "doubler" where you take the low range unit off the 203 and bolt it onto a 205 with adapters for a 4:1 low range. For the price of patching together all of that and adding another crossmember is about the same as an atlas. And the atlas is smaller and weighs less (people have snapped off the end of their transmission with an incorrectly mounted doubler). And I could then get these ratios 2.0:1, 2.72:1 & 5.44:1 or even 2.72, 3.0:1 & 8.16:1

I've almost crashed several times going down trails that were so steep I had to ride the brakes all the way and they kept wanting to lockup. The jeep/toyota guys just geared down and idled down the same trails without any drama.

 

[PrairieDrifter]

They jeep guys also have less weight than we do. Also I believe removing the manual hubs is what did your chain in, if my thinking is correct.

 

[Snoots]

Believe It Or Not, I've put over 350K miles on my 203. Lock/unlock hubs and I've never run 4WD on anything but mud or snow.
I've pulled the shifter off and rebuilt it and that's all.

 

[77 K20]

Another small sad update. Shop said it would cost around $900 to rebuild my existing transfer case- and will probably take a month or two. Parts are hard to come by/backordered.

So I did stupid option #2- I bought a used full time case at a junkyard today ($225). They do offer a 30 day warranty that it won't explode in that first month.

Being fulltime will hopefully prevent that chain exploding on the highway.

It will be SO nice to have the truck back to drive it (easily). In the meantime I'll be saving up to either get that Atlas case, or looking at ORDs doubler, but with the Magnum underdrive. Both units cost about the same. And both of them have a 2-3 month lead time also.

So just a band aid fix for now- but next year will have what I actually want. Something very strong and very low geared.

 

[77 K20]

Hell, for a lot less than $300 you can have a 205 and never worry about breaking it again. That atlas is stupid expensive isn't it?

The junk yard did have a NP205 there- but they want $300 for it and it has the wrong input splines as it was for a manual trans. They said the transfer case needs to be rebuilt also as when you spin it by hand it isn't smooth. A new input shaft is $150 plus shipping. I did find another 205 that was 4 hours away. They want $600 for it and once again it has the wrong input shaft spline count.

They are just hard to find around here and if you do they want your first born.

There used to be a company called lomax that made a nice 3:1 low gear reduction which I'd really need. They are no longer in business.