If you leave the ADD drive flanges on then your front axles and driveshaft are spinning all the time. You can shift in and out of 4WD any time (shift on the fly). With manual hubs, you can unlock them when 4WD is not needed to save wear and tear on the front drivetrain. When 4WD might be needed the hubs can be locked and then you have the same scenario as the ADD drive flanges. You can shift on the fly into and out of 4WD.

 

I get it now. Sounds like it would be better to gut it and make the swap to manual Aisins rather than having all of that turning all the time. My ADD is working fine so I think it will hold up until then. I like the idea of having the 2lo as well.

 

You can do it in stages, swap to manual hubs and retain the ADD. This saves the constant wear and tear on the CV boots you get w/ ADD. Then later you can delete the ADD if you decide to, for better reliability.

 

That sounds better yet Roger. How would that be done? Can the swap be made without touching the ADD system, or does that include the mod to the actuator fork in the writeup? Does the actuator assembly eventually get removed as part of the gutting of the ADD or is that essentially what the mod allows for? Or, is it left intact altogether?

 

There are a bunch of writeups on defeating or deleting ADD, read them and decide what you want to do. I've never had a truck w/ ADD nor ever worked on one, so I only know what is written in the on-line pages, one posted above and another below:

http://www.off-road.com/toyota/tech/add/index.htm

So you can either leave the ADD stuff all intact and functional. You can configure the vacuum lines to leave it engaged all the time. You can lock the internal mechanism to leave it engaged all the time, or you can swap the ADD actuator part for the non-ADD version of that part.

 

I don't think I'm going to be in a big hurry to do it. I was looking at the conversion kit on Downey's site and it's $700 for the kit including hubs.

 

No need for the Downey kit, just pick up a pair of used Aisin hubs at the junkyard or off eBay and put those on.

 

I was looking at the diagram in the manual and it shows both hubs side by side. It appears from the illustration that the only differences are the manual locking knob, a 6pt gasket behind the knob (between the cover and housing). The ADD hub didn't show the gasket, but did have a donut-shaped thing behind the housing. It was hard to make out from the b&w drawing and also due to the size. There's a set of Aisins on ebay now for $50...

 

Dr. Feelgood-the downey kit is for 3rd gens and tacomas...just unbolt our flanges and bolt on the aisins, simple as that it took me 30 mins.
Remi-here's the pics sorry for the delay, as far as lift they usually end up at around 3" but theres variables as they are a used spring that can sag, fortunately mine are pretty new ('98) and the way I've got em is right about 2". these are a couple old pics of the hangers, i've got the skids completed now. Plus chevies ride nice and soft like a luxury car (k maybe not quite but you know nice for a truck)

 

The ADD hubs are technically drive flanges, basically no moving parts, just a permanently locked hub. Have not seen any up close, but here is the same thing in a solid axle drive flange (on the left) and a manual locking hub (on the right):