The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > General Truck Forums > Engine & Drivetrain

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 08-17-2017, 10:22 PM   #1
Stokester
Registered User
 
Join Date: Apr 2015
Location: Katy Texas
Posts: 69
Np203 question!

Ok let me start by telling you the original issue. I have some driveline clunk when I put into gear and when I let off gas. Ujoints r good! It coming from tcase. I took it apart and wanted to order the part time shaft kit. Well it appears that they no longer sell the part time shaft replacement only the 501 gear replacement. So I ordered a seal kit and the MM501 part time gears kit. Today it showed up and went to install!!! Well I believe I have a part time kit already installed but I can't find any info on this set up. I searched and searched with no luck! Can someone tell be what I have and if I can or should use the MM501 kit. I think there is some slack in my chain but it does not seem to be excessive! I think my drive line clunk came from needing another shim or 2. Any advise/help would be appreciated!
Attached Images
   
__________________

72 blazer 4x4 4" 35's
02 f150 work truck
15 f350 super crew long bed 6.7 4x4(stock but loaded)
02 f350 horse hauler 7.3 (need to sell)
Stokester is offline   Reply With Quote
Old 08-18-2017, 09:43 AM   #2
Stokester
Registered User
 
Join Date: Apr 2015
Location: Katy Texas
Posts: 69
Re: Np203 question!

Bump!
__________________

72 blazer 4x4 4" 35's
02 f150 work truck
15 f350 super crew long bed 6.7 4x4(stock but loaded)
02 f350 horse hauler 7.3 (need to sell)
Stokester is offline   Reply With Quote
Old 08-21-2017, 11:18 PM   #3
Stokester
Registered User
 
Join Date: Apr 2015
Location: Katy Texas
Posts: 69
Re: Np203 question!

Bump!!! Anyone!!!!
Posted via Mobile Device
Stokester is offline   Reply With Quote
Old 08-21-2017, 11:47 PM   #4
mongocanfly
Post Whore

 
mongocanfly's Avatar
 
Join Date: May 2015
Location: Alabama
Posts: 14,582
Re: Np203 question!

I'm probably no help but I found this ..it doesn't look like your pics....https://ck5.com/forums/resources/mil...t-time-kit.68/
mongocanfly is offline   Reply With Quote
Old 08-22-2017, 02:05 PM   #5
Stokester
Registered User
 
Join Date: Apr 2015
Location: Katy Texas
Posts: 69
Re: Np203 question!

Thanks mongo! I've seen that one but can't find any info on the one I have!! Anyone ever used or seen the one I have???
Posted via Mobile Device
Stokester is offline   Reply With Quote
Old 08-22-2017, 03:11 PM   #6
Stokester
Registered User
 
Join Date: Apr 2015
Location: Katy Texas
Posts: 69
Re: Np203 question!

Thanks mongo! I've seen that one but can't find any info on the one I have!! Anyone ever used or seen the one I have???
Posted via Mobile Device
Stokester is offline   Reply With Quote
Old 08-22-2017, 06:48 PM   #7
kwmech
Senior Member
 
Join Date: Mar 2003
Location: Colfax-California
Posts: 8,388
Re: Np203 question!

I believe that is an old Selectro Kit. so what's wrong with it? If you hear banging the case it is more than likely your chain
kwmech is offline   Reply With Quote
Old 08-22-2017, 10:22 PM   #8
Stokester
Registered User
 
Join Date: Apr 2015
Location: Katy Texas
Posts: 69
Quote:
Originally Posted by kwmech View Post
I believe that is an old Selectro Kit. so what's wrong with it? If you hear banging the case it is more than likely your chain
It is not a banging. I just have/had some driveline clunk! I do have some slop in the chain (not sure how much is to much)but not skipping teeth or anything. I put it on jack stands and I have front driveshaft rotation in all positions. I thought this was supposed to be a partime kit?? I put another shim in when I put it back together and adjusted tv cable. It really seemed to help the driveline clunk. Question I have now is why do I have front driveline movement in in all 4 positions? Is this installed incorrect? I have the MM501 kit. Not sure I can install it now since I don't have original shaft. I also have a 84 parts blazer that has a 208. Should I just swap to the 208? Any advise would be appreciated!!!
Posted via Mobile Device
Stokester is offline   Reply With Quote
Old 08-23-2017, 09:20 AM   #9
cadillac_al
Registered User
 
Join Date: Oct 2013
Location: Maine
Posts: 2,334
Re: Np203 question!

I used to buy up used 203's for $50. I have enough now but I wouldn't drive anything else. I would just buy another one and enjoy the effortless all terrain capabilities.
__________________
76 Chevy K20
76 GMC K15
77 Chevy C10
77 Chevy K10
cadillac_al is offline   Reply With Quote
Old 08-25-2017, 09:59 PM   #10
gvw5400
Registered User
 
gvw5400's Avatar
 
Join Date: May 2013
Location: Colorado Rocky Mountains
Posts: 263
Re: Np203 question!

I had one way back in 1980, I converted to part time with a Doug Nash shaft kit.
Looking at the photos it looks like the parts shown would drive the rear drive shaft all the time. that is good. You might check the sliding collar in front of the 4 bolt spider gear case. If it is not moving the sliding gear to the front you will always have the front drive engaged.
All the Best, Dirk
gvw5400 is offline   Reply With Quote
Old 08-25-2017, 10:55 PM   #11
EmJay
Registered User
 
Join Date: Aug 2017
Location: Johns Creek, GA
Posts: 10
Re: Np203 question!

I have that kit in my transfer case as well, it was a pleasant surprise when I went inside mine to clean it out and refresh it.
These cases are designed to be full time 4wd. The kit in yours makes it so that you can keep moving when the front axle loses traction. Jack up just the rear of your rig and spin the rear axle, it will. This kit also allows you to switch to manual hubs. Strange enough people with the 203 cases love his kit, but it is long since discontinued.
Posted via Mobile Device
EmJay is offline   Reply With Quote
Old 08-26-2017, 04:03 PM   #12
Stokester
Registered User
 
Join Date: Apr 2015
Location: Katy Texas
Posts: 69
Quote:
Originally Posted by gvw5400 View Post
I had one way back in 1980, I converted to part time with a Doug Nash shaft kit.
Looking at the photos it looks like the parts shown would drive the rear drive shaft all the time. that is good. You might check the sliding collar in front of the 4 bolt spider gear case. If it is not moving the sliding gear to the front you will always have the front drive engaged.
All the Best, Dirk
Thanks dirk! That would make sense! I will look at that! If it's not sliding then what? Can I still get that part? If not what are my other options?
Posted via Mobile Device
Stokester is offline   Reply With Quote
Old 08-30-2017, 10:02 PM   #13
gvw5400
Registered User
 
gvw5400's Avatar
 
Join Date: May 2013
Location: Colorado Rocky Mountains
Posts: 263
Re: Np203 question!

Thanks dirk! That would make sense! I will look at that! If it's not sliding then what? Can I still get that part? If not what are my other options?

Sorry for the delay, Work has been so crazy no time for trucks.
You might check the 2 shift arms and the Hurst shifter, one arm shifts in/out of Loc,(2/4 wheel dr.) the other engages high vs. low range. look at the shift fork for easy engagement.
You might not need any parts, just check for function and proper movement.
As I remember 1979 was the last year Chevy used the 203.
All the Best, Dirk
gvw5400 is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 05:08 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com