Flame away but when I searched for help on this subject I found nothing so I figured I'd post this if anyone else runs into the same problem.

Ok I was attempting to install a MileMarker part time kit (#501 yea the gear kit :flipoff2: ) in my NP203 last weekend when I ran into a snag. When I pulled the tailhousing off I discovered I had the 73-74 (1st gen) case with the solid carrier on the output shaft (pic 2). The instructions in the MileMarker kit says to replace the shim (pic 3) with one for a 75-80 (2nd gen) case (pic 1).
I was told by a driveline shop & a 4x4 shop that about the only way I could get the part was to pull one out of anoter case since the parts were discontinued. I called MileMarker and they told me I should try the dealership but they didn't know the part numbers. Well today I ran to the Chevy dealership and after about a half hour trying to figure out the exploded view (on a computer no less and backwards from how I was used to looking at it) we finally found the shim and it's still available! BTW the shim I need to replace IS a discontinued part so if there's any chance you may go back to full time hang onto this shim!

Ok here's the part numbers for the shim and a couple of seals you should replace anyway while you're at it.

347442 ------- Front Shaft Spacer ------ $9.23
344278 ------- Output Shaft Seal ------- $9.05 (this is the one inside the intermediate housing ahead of the bearing)
12338062----- Inner Yoke Seal --------- $1.81

So basically Find a 75-80 Second gen caseand don't mess with the 73-74 is what your saying. right:D

I know when we(pop and I) did this in my old 79 dodge(second gen case) it was a peice of cake.

Very good post:flipoff2: :D

Originally posted by syko
So basically Find a 75-80 Second gen caseand don't mess with the 73-74 is what your saying. right:D

I know when we(pop and I) did this in my old 79 dodge(second gen case) it was a peice of cake.

Very good post:flipoff2: :D


Actually IMHO the carrier in the 73-74 case looks WAY stronger. When I bolted the two halves togeather the output shaft was LOCKED in, no slop whatsoever period end of story.
Also if I ever do start to get play in the kit I figure I can always weld it up solid kinda like a Lincoln locker.

All you have to do is make sure you have this spacer on hand before you start the swap and as far as the seals, you should replace those anyway with either case design.

I forgot to give some credit in my first post. I want to give Grim Reaper a HUGE THANK YOU for all his help and for pointing me in the right direction!!!!! :D

MileMarker Part time kit?

What's that?

Do you mean a way to run a pump when you need it off the tranny?

Any details on the pump - psi and gpm?

Sorry for the newbie questions - I've a MM working on a D90, running with a second oil pump on the engine, but it's not enough. Want more speed. :flipoff2:

Merv,
The MileMarker kit he is talking about has nothing to do with winches. All the kit does is convert the NP203 from full time 4wd to part time 4wd. Just thought I would chime in before someone lays into you. Welcome to the board newbie. Thomas:p

Merv,

Its like the part time kit for an LT230

You will have to forgive merv, any talk of shafts and tailhousings and he gets all flustered.

:)

Ron

WOOPS.

Thought he meant the Mile Marker Winch.

I'll shut up now.

UPDATE!!!!!


The spacer 347442 ------- Front Shaft Spacer ------ $9.23 IS no longer available after all.
Got a call from the dealership this morning ad all my seals are in already but the spacer unavailable. :(