NP203 Conversion Kit question

[Wildjoe330]

I worked for the company that invented and patented the 203 part time conversion back in the 70's. I have installed thousands of part time conversions. mile marker was one of the many companies that ripped off the design. the company I worked for eventually won in court but not after these rip offs with their inferior kits flooded the market. I have zero respect for mile marker and the others, they all knew what they were doing and did it anyway. my 2 cents. highdesertranger

What are the best parts and way to go from full time to part time in my 77 C20?

Thanks

 

[Wildjoe330]

Does anyone know where I can get a shaft or shaft kit for my 203?

 

[firebane]

shaft kits are pretty much non existent and if you did find one you could buy a 205 for cheaper lol.

 

[tbartholomew]

I have a 74' K-10 and I'm installing the mile marker part time kit (501) with the 4 tabs you install into the differential housing in my 74' NP203. The direcions from mile marker are very vague but says a spacer in a 73-74 truck needs to be replaced with the spacer from a 75'+ unit. I believe I got the correct spacer, from a local off road shop but with the flat bearing sandwiched by the two flat races now rest on the crown gear. The shop gave me two of the spacers but I'm a little confused as to whether I'm supposed to use both. If I use both spacers it puts the flat bearing and races further away from the crown gear than the original spacer with the shoulder does. Hope this makes sense? I'll attempt to upload some photos to better understand my dilemma.

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[tbartholomew]

Spacer on the left is from a 75' or newer np203 which I was given two, the right one is my original. The 2nd/3rd pics is of newer single spacer installed with the washers/bearing. The fourth is of both spacers I was given by the shop. The last one is of the original spacer with the shoulder and washers. Any advise would be much appreciated!

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[Wildjoe330]

How did your 203 rebuild come out? Did it have the 50 to 65 mph vibration in it before the rebuild? after the rebuild???

 

[Wildjoe330]

shaft kits are pretty much non existent and if you did find one you could buy a 205 for cheaper lol.

I found a shaft kit and put it together works fine, now how about a 205. lol. probaBLY should sell out of the 203. ha.

 

[MrMarty51]

I found a shaft kit and put it together works fine, now how about a 205. lol. probably should sell out of the 203. ha.

If You go for the 205 T~Case, Be sure that the adapters comes with the T~Case for the transmission that is in Your truck.
I have a T~Case and adapter for a TH350, My truck has a TH400. If You have not priced the components necessary to make the case fit to Your transmission, I would suggest doing so, before You go getting the 205. You will be shocked.
That is the reason that My 78 K20 still has the 203 T~Case.

 

[Wildjoe330]

If You go for the 205 T~Case, Be sure that the adapters comes with the T~Case for the transmission that is in Your truck.
I have a T~Case and adapter for a TH350, My truck has a TH400. If You have not priced the components necessary to make the case fit to Your transmission, I would suggest doing so, before You go getting the 205. You will be shocked.
That is the reason that My 78 K20 still has the 203 T~Case.

MrMarty, Has anyone chased that front bearing on the output shaft on the 203?

Thanks for that info MrMarty51 I just reviewed that I have the th350.

 

[MrMarty51]

MrMarty, Has anyone chased that front bearing on the output shaft on the 203?

Not sure.
I bought the entire rebuild kit through NAPA, One box with all the bearings seals and etc. I dont remember the price of it though.
I think if the bearing was removed and the numbers from it were called in, that it should not be too much of a pwoblem.
Somewhere in here, I had a pretty good write up on going through the T~Case. All but towards the end. I messed up and kept forgetting to take pics. and add them into the thread.

 

[Wildjoe330]

Was told by a long time sales person that they used to knock off or even grind off the drum balance weights so new rims would go on.



77 K20, 50 to 65 mph pulsating Vibration, Was Full Time, Replaced front axle u-joints, Cab Body Bushings, Front Wheel Barrings gone thru, Upper Lower ball joints, New front pads, New Lockouts, Used Part time Kit, Rear drive line Balanced New U-joints, New Tires/Rims Balanced, New Transmission Mount, 350, TH350, NP203, 7/14 10:22

 

[Wildjoe330]

Not sure.
I bought the entire rebuild kit through NAPA, One box with all the bearings seals and etc. I dont remember the price of it though.
I think if the bearing was removed and the numbers from it were called in, that it should not be too much of a pwoblem.
Somewhere in here, I had a pretty good write up on going through the T~Case. All but towards the end. I messed up and kept forgetting to take pics. and add them into the thread.

yea, I wondered if rebuilding that 203 will take away the 50 to 65 pulsating Vibration Because these 203's are in the Ford, Chevrolet, Dodge? and I heard that a dodge had the same problem. let us know if you get that 203 rebuilt and if it takes out the 50 to 65 mph pulsating Vibration. Thanks.


77 K20, 50 to 65 mph pulsating Vibration, Was Full Time, Replaced front axle u-joints, Cab Body Bushings, Front Wheel Barrings gone thru, Upper Lower ball joints, New front pads, New Lockouts, Used Part time Kit, Rear drive line Balanced New U-joints, New Tires/Rims Balanced, New Transmission Mount, 350, TH350, NP203, 7/14 10:22

 

[Camar068]

oh my....hmm.....sounds applicable.......where's my red stapler

yea, I wondered if rebuilding that 203 will take away the 50 to 65 pulsating Vibration Because these 203's are in the Ford, Chevrolet, Dodge? and I heard that a dodge had the same problem. let us know if you get that 203 rebuilt and if it takes out the 50 to 65 mph pulsating Vibration. Thanks.


77 K20, 50 to 65 mph pulsating Vibration, Was Full Time, Replaced front axle u-joints, Cab Body Bushings, Front Wheel Barrings gone thru, Upper Lower ball joints, New front pads, New Lockouts, Used Part time Kit, Rear drive line Balanced New U-joints, New Tires/Rims Balanced, New Transmission Mount, 350, TH350, NP203, 7/14 10:22

hmm.....sounds applicable.......where's my red stapler.....has anyone seen my stapler.....

 

[Wildjoe330]

Does anyone running a 205 have the 50 to 65 pulsating Vibration?



77 K20, 50 to 65 mph pulsating Vibration, Was Full Time, Replaced front axle u-joints, Cab Body Bushings, Front Wheel Barrings gone thru, Upper Lower ball joints, New front pads, New Lockouts, Used Part time Kit, Rear drive line Balanced New U-joints, New Tires/Rims Balanced, New Transmission Mount, 350, TH350, NP203, 7/14 10:22