914runner

Well here it is the cure for ADD!
http://www.4x4wire.com/toyota/tech/add/
I found this write up on 4x4wire while looking around and thought id post it for those of you who havent seen it.

HaveBlue

My cousin has to take pills to cure his ADD. Oh, wait...:pat:

Flygtenstein

So you mean swapping manual hubs does not do that?

That is a Christmas project for sure. No time to mess around anywhere near a garage before then.

paddlenbike

iTrader: (1)

For those of you removing the ADD system, I'll take your two VSVs that mount on the passenger's side of the engine compartment. One of mine went bad.

keisur

but make sure you read the whole write-up good. You want to swap to manual hubs if you 86 the ADD otherwise the diff will be working extra hard in 2WD and from what I can understand, bad things will happen at higher speeds. so don't do it unless you also do the manual hub conversion also.

This is why it is not good to drive around in 2WD with your manual hubs locked.

00Runner

Is there any down side to retaining the ADD system if you have done a manual hub conversion? I could see an advantage if you were going to be using 4wd for traction in snow. You could lock your hubs before you got to the snow level so that you could just shift in and out of 4wd when you needed it. This seems like the best of both worlds.

anthony1

iTrader: (1)

You are correct. Give this man a prize.
I converted my hub to manual right after I bought it used. I still have ADD and it's working great. I would disable it only if you're putting locker in it.

paddlenbike

iTrader: (1)

I have manual hubs with my ADD system. When I lock my hubs, it's just like having the ADD system still hooked up; the passenger's side axle shaft spins and also spins the r&p, but not the front driveshaft. Pull the lever on-the-fly for 4WD.

You can also unlock the hubs and have 2WD low. So you basically have more options when you maintain ADD and install manual hubs.

But one day my truck failed to go into 4WD. One of the VSVs went bad. I tried to switch vacuum lines at the VSVs to lock it in 4WD, but that did not work. I ended up switching vacuum lines down at the diff and that did work. It has been that way for a year now. I'd like to find a new VSV to replace my broken one, hint hint.

keisur

buy me one of these and I'll "give" you mine!

Flygtenstein

Driving around with my hubs locked is exactly as if I had a 3rd Gen runner without manual hubs.

Disabling ADD does nothing to the shift on the fly ability. If you pull the lever and the hubs are locked, you have 4wd, period.

LarsDennert

Ideally if you replaced the whole axle with a non ADD IFS axle you'd get the larger idler shaft. Then again SAS would be even better but I digress in to useless chatter.

SteveO

Personally I prefer the have the ADD intact. When I encounter patches of snow and ice, I can push the little button on the side of the 4wd lever and have full time 4wd (when the hubs are locked in). What is really cool, is that I can drive this thing on the drive asphalt up to 62mph in 4wd, if necessary. Then push the little button and out of 4wd (technically speaking 2wd, 1 in front and 1 in rear). The more options the better, until it breaks. Having the write-up is good information to know when it does break, we will have info on how to fix it, or remove it.

keisur

Locking the hubs and disabling the ADD (so that the diff is engaged fulltime) will cause the front R&P and the front drive shaft and the output shaft on the t-case to spin in 2WD. Not very good for the system. Cuases alot of un-needed stress on the front drive assembly and also burns more gas! All-in-all it's not a good idea unless you convert to manual hubs.

A quote from the end of that write-up:

Here's more reading for the ADD system (as much as I hate to plug Randy's but here it is anyway):

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