How to? converting full-time hubs to manual

[ScottH]

I'll be picking up a 79 K10 this weekend which has full-time hubs on it. Seems everyone agrees that it would be best to have manual hubs, so not being familiar with 4x4s I thought I'd post a how to question on converting.

So can anyone enlighten me as to what is involved (remember, 4x4 dummy), what parts needed, donor trucks that parts could be used from, and approximate costs? Any information or suggestions would be greatly appreciated.

Thanks.

[1969k10stepside]

If you convert it to a manual hub truck you will either have to modify the np 203 transfer case for lockouts or the easier way IMO which is just to get a Np 205 transfer case.I cant help you on the axle part because I have never did it.I would just try to pickup a 4x4 chevy with lockouts and put that axle under the truck and switch the transfer cases too.

[Mudder]

Buy a set of man lockouts for the axles and get a gear for your 203. The gear goes into the front of the TC. Can't remember but there may be a couple of companies that make the conversion gear.

[LONGHAIR]

Yeah, just get the conversion kit, it's not hard to do. You just have to remove the rear extension housing and swap out the spider gears. They are removed and replaced by a solid connection. Some kits use a single solid gear, others use individual spider gears that do not rotate on the cross shaft. Either one works fine. It is a simple swap that can be done in the driveway in an afternoon. The only thing you need that is not in the kit is some motor oil. All of the ones I have ever installed tell you to replace the little bit of gear lube that you lose during the removal with regular motor oil. The directions are usually pretty good and have pics.

Swapping to a NP205 is a lot more work and expense.

[msgross]

Or just drive the truck "as is" until you get extreme with your offroading. I drove my 79 blazer with full time 4WD for years and only got stuck bad once (that was a newyears I don't want to remember though! but it was fun...) I never did anything extreme with it but as a highschooler trying to show off to his friends you can imagine I gave er hell.

[LONGHAIR]

Or just drive the truck "as is" until you get extreme with your offroading]

You could, but there is no good reason to do that. It will feel so much better to drive by taking that extra drag away from the driveline. It is usually claimed to increase fuel mileage too. I have never checked that, but I know that any truck/blazer that gets the kit instantly feels like it has more power and steers better too.

[ScottH]

Thanks guys. Picked the truck up today, have some things to do first but if I hold onto it sounds like a good thing to do.

[msgross]

I use to remove my front driveshaft during the summer...to cheap do a conversion.

[LONGHAIR]

I use to remove my front driveshaft during the summer...to cheap do a conversion.

I'd really like to know how you pulled that off..............

If you remove the drive shaft, all of the power from the transfer case would go to the front yoke anyway. None would go to the rear and the truck would not even move..........unless you shifted it into "lock", which defeats the whole purpose and the front axles would still turn with the wheels too.

The "conversion" removes the spider gears, which act exactly like those in a open rear-end. The kit removes the differential action, then the front drive is either locked or unlocked.

[72 CustomCamper]

Originally Posted by msgross

I use to remove my front driveshaft during the summer...to cheap do a conversion.

Me too. I'd also pull the drive flanges out and keep them in the truck...


Chuck

[1969K10]

Originally Posted by LONGHAIR

You could, but there is no good reason to do that. It will feel so much better to drive by taking that extra drag away from the driveline. It is usually claimed to increase fuel mileage too. I have never checked that, but I know that any truck/blazer that gets the kit instantly feels like it has more power and steers better too.

For what it's worth, I get ~14MPG in 2WD, when I lock in the front axle, I go down to ~11MPG. Then engaging my X-fer, doesn't really make a difference...

[msgross]

Originally Posted by LONGHAIR

I'd really like to know how you pulled that off..............

If you remove the drive shaft, all of the power from the transfer case would go to the front yoke anyway. None would go to the rear and the truck would not even move..........unless you shifted it into "lock", which defeats the whole purpose and the front axles would still turn with the wheels too.

The "conversion" removes the spider gears, which act exactly like those in a open rear-end. The kit removes the differential action, then the front drive is either locked or unlocked.

maybe mine was auto hubs and not fulltime 4WD then...what came on a 79 blazer? I know I pulled the driveshaft and kept on driven. I always got the same mpg so it didn't really matter.