The TRUTH about 4WD to 2WD ?

[GARMCo]

Hello-- would like to convert my 73K5 from Full-time 4wd to Part-time. I've heard that you can't just install aftermarket hubs (like Milemarker, Warn, etc.) without doing some type of conversion to the transfer case (NP205). Supposedly, this causes undue wear on the transfer casae internals, and you end up causing slack and clunking in the future. Are there any shortcuts, ideas ?? I'm trying to look for ways to get better mileage given these quickly rising fuel prices. Thanks!

[Jonboy]

The conversion is not hard to do at all. You do have to pull the rear extension housing off, and install the blocks. I had mine for about 6 years, through a ton of torture and it held up fine. I went through a range of engines, from a 327, a couple of 350's, the original 400 (twice!) and a 454 for a short while. Most of mine were performance oriented, but it never got great mileage, ever. If you could swing it, a 700/NP208 combo would be ideal, but it would be a little costly, and pretty hard to make up with the savings on fuel.

[Grim Reaper]

First off if you keep your tires rotated and even wear then the cost to part time it will take you about 50k in MPG to get even close to breaking even on the cheap kit (501 model). The better kit it will take 100k.

The biggest issue that gave the 203 a bad rap is dumb owners. If you change two tires at a time then the 4 tires are not the same diameter and you start having loss through the center diff. It also puts more strain on the chain and does cause it to wear faster.

I saw almost no MPG gains by going to part time but I keep my tires rotated and change all 4 at a time.

Here is the information on the part time kits.
http://www.coloradok5.com/milemarkerpt.shtml