79 Jimmy Transfer Case Options

[79 Jimmy YT]

Hello, I have a 79 Jimmy which is in beautiful shape beside the loud BANG it makes when load is put on the drive train. My previous mechanic is "tired" of working on such a highly technical and mind boggling machine, and has thrown in the towel with the final words of "your NP203 transfer case chain is slipping and I can't find a replacement".

We have not been able find a NP203 replacement yet, so I am curious if the Jimmy (automatic) is compatible with other types of Transfer Cases? Or is a rebuild kit another option, looks complicated? Thoughts?

Thanks in advance,

Tony,
Whitehorse, YT
Canada

 

[diesel4me]

There are other options,its always easiest to put back what it had originally of course though..

First off,you'll need to know which tranny you have--TH350,or TH400..the TH350 has 27 splines on the shaft that go into the T-case and the TH400 has 32 splines..the rest of the NP-203 is the same otherwise..

I have put a NP-205 gear drive transfer case in a 77 GMC I had,that had a NP-203 originally..the front driveshaft was too long to fit ,so I had to find a shorter one,but the rear driveshaft bolted in fine,as did the mounting "foot" on the crossmember,I did have to cut another hole in the tunnel for the NP-205 shifter,its mounted differently than an NP-203 is..

You can put other transfer cases in your truck too,but driveshafts and various other parts might have to be changed..

Here is a few links I found by typing "NP-203 parts" on Google --looks like you can buy just the chain for about 50 bucks...
EDIT--thats for the sprockets!..if you google NP-203 drive chain you'll find listings,one is about 125 bucks..

http://www.offroaddesign.com/catalog/transfercaseparts.htm

http://www.drivetrainpartslasvegas.com/category_s/2012.htm

 

[dremu]

Yeah, uh, find you a new mechanic. '203's are everywhere and parts are easily available for them.

-- A

 

[79 Jimmy YT]

Thanks for the info guys.

I like the 205 seeing as it isn't 4x4 all time. The 203 seems to fight the pavement quite a bit in the summer. We originally had a 205 I believe, because we could 2x4.

Are there any other addition parts for a Np205 conversion needed besides a TC, shorter front drive shaft, and new hole?

I am not sure what transmission my dad and I have, the serial number is 468269, MCM 2. I attached some photos of the truck, maybe you guys can tell from the photos?

 

[79 Jimmy YT]

Here is a link to the photos

 

[72blazerguy]

a quick google search http://www.drivetrainpartslasvegas.com/category_s/2012.htm

Offroad Design might be able to help as well.

 

[79rustyk10]

Don't mess with the 203. A 205 with the right spline count will bolt in. Or if you want to go even better than that do a 700R4/208 swap. However both will require driveshaft mods.

And get a new mechanic.

 

[chevy4x4power]

Don't mess with the 203. A 205 with the right spline count will bolt in. Or if you want to go even better than that do a 700R4/208 swap. However both will require driveshaft mods.

And get a new mechanic.

Are 205's readily available near ya'll for reasonable prices? I'm having a hard time finding 27 spline 205's

 

[79rustyk10]

It's not too hard around here, but they're not common like they used to be.

 

[diesel4me]

I kept the NP-205 I had in my 77 GMC after I swapped it in place of the NP-203 when the truck was too rusted to be roadworthy any longer..dont know if I'll ever use it again in anything...

I kept the ailing NP-203 too,in case I wanted to make a doubler or sell it for parts--it had a skipping chain too,I guess thats a common problem,if you took off fast it would go "bang"....its been in my shed 15 years now I bet..have the shifter too...

I spent a good hour last night searching google--the chain for the NP-203 DOES seem to be "discontinued",I found a Cloyes and Morse part #,but no vendors selling one!....