"12 gauge"--78 crewcab --- aka "Old Diesel Truck"

I flew to OK city with the intention to drive it home. made it 500 miles and it lost all drive power. i think a problem with the 203. i was going down I44 in MO and had sudden grinding. coasted to the side and couldnt get it to stop grinding no matter where i had the transfer case or tranny. in park, and any position of the transfer case it will still roll forward with a push. also with the tranny and t.c. it still sounds like the transfer case still shifts.  got any ideas on what might be wrong? needless to say, i took a cab to st louis about 60  miles, grabbed a plane ticket home and turned around with a truck, trailer, and really good friend and pulled it the 600 miles home! so now its in the garage and i'm wondering what i should do. take out the 203 to troubleshoot or is there something i can do with it still in the truck?  i'm pretty excited even though its not off to a good start!

  Sounds like an adventure, but at least you got your new truck home.  Looks like a great project.  Is this going to be another CTD?  Sorry I can't help you with the grinding problem.  I am sure someone will chime in shortly.

ctd would be nice but i'll probably stick with what i know. for now i will just clean up the 318. i have a 360 block that i got bored .40 so i can build it slowly as funds come in unless somebody buys it with my 86 listed in the classifieds. for now my goals are these: floorboard on passenger side needs replaced due to crack, small amount of body work to be completed like straitening front valence and grill from slight bend, and patch some holes in roof from light bar of fire dept. and then paint. after that i want to lift, probably 4". next i want to finish the interior, i have a black dash pad and i will dye the rest to match. mainly i want to get it on the road for a daily driver and then finish as funds allow. ultimately it'll be a way for me to have an old dodge i love and fit the family that i love more!

I test drove that truck back in the Fall. Just didn't want to spend the asking price.

I believe the t-case is shot. Possibly broken chain or the t-case differential itself. That's why it will still roll & grind even in park.

Those NP203's are plentiful. They were in most M880 5/4 military Dodges & can be found "new" or rebuilt. If you can remove you old one & reinstall a new one yourself, you should be able to keep the costs under a few hundred bucks. Dodge used that tranfer case from 75-79 in Pickups & in 74-79 Rc's.

Yeah, he ended up coming down 900 off the price i saw on c.l. they are just so hard to find in any condition around here. i paid 3 grand for it. around here that isnt a bad price for a rust free truck with d60's, especially a crew. i think this is only the second one in the area. i kindof figured the differential in the t.c. was shot due to the fact that it sounds like it still turns even when the tc is in neutral, i was assuming the chain was still intact

looks nice Man

Thats a cool truck and 3K isn't bad for a 70s crew in decent shape.

I didnt think so. Last night i removed the 203. didnt find anything that looked horrible when i pulled it out. i removed the aluminum "cone" off the back where the rear driveshaft connects. all the gears looked to be okay. this is where i thought the problem would be. also, how tight is the chain supposed to be. i could get a little play when prying on it with a screwdriver but i looked okay. where else could the problem be, or am i chasing what is actually a tranny problem?  i did notice that somebody installed this t.c. because it had red sealant gobbing out where it connects up front to the adapter. also, somebody put gear oil in it rather than 10w30 oil...more help please...

Nice lookin truck!!!! Glad to see another crew cab being saved from a potential moron owner who might molest or destroy it!!!

If you wind up finding you need a t-case or trans, and can't find one locally let me know I come across them and actually may have a 203 at a friend's in a parts truck thats kinda both of ours. That and I am always wheeling and dealing trucks and parts and parting out trucks and stuff...

mttaff said:

I didnt think so. Last night i removed the 203. didnt find anything that looked horrible when i pulled it out. i removed the aluminum "cone" off the back where the rear driveshaft connects. all the gears looked to be okay. this is where i thought the problem would be. also, how tight is the chain supposed to be. i could get a little play when prying on it with a screwdriver but i looked okay. where else could the problem be, or am i chasing what is actually a tranny problem? i did notice that somebody installed this t.c. because it had red sealant gobbing out where it connects up front to the adapter. also, somebody put gear oil in it rather than 10w30 oil...more help please...

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Is it a manual or auto? Manual I run gear oil and I have heard auto you run ATF.

its auto.

10W30, is the proper lube for the 203.

is it possible i just burnt something up in the transfer case due to the heavier oil and the 500 mile trip? i cant figure the problem!

That very well could have, usually the chain is the first to go, nut you said it did not seem to bad.

If you have both drive shafts disconnected, put the trans in N, and turn the TC output yokes, and see how they turn, and feel.

I already dropped the transfer case out of the truck...is there any way i can test it while it is out?

Yea, just turn everything, and see how it feels.

I don't have it handy, which is which, but the two shift levers, one is for Low, N, High, and the other is for full time, and loc.  Try moving them to different positions, and see how everything turns.

With the one in Loc, the two output shafts should only turn together, with it out of Loc, they should be able to turn separately (you can hold one still, and turn the other )

You can also put the tranny in N, and turn the output shaft, and see how that turns.

I will give that a try when i get home in the morning. this is a little above my pay grade to troubleshoot at this point! lol  i can usually fix it once i figure out what the problem is though!

mttaff said:

this is a little above my pay grade to troubleshoot at this point! lol

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Never!, you just have to do what you are doing, and ask questions, and keep your mind open to learning.