IFS Front Diff - Converting from ADD to Non ADD

[Micky-Lux]

Anyone done it? Any tricks or ideas?

Reason I ask is I've been trying to sort this one out for a while. I've fitted freewheeling hubs, and locked the ADD actuator. However, there was a fair bit of slop in the actuator.

I purchased a LH side inner driveshaft and tube (well two of them actually) and both appear to be the same. They are both suposed to be off a 167 series (mine's an LN167), yet when in the diff, the shaft doesn't appear to fully seat in the tube. The splined end appears to fit into the centre, and it locks in place. When I place the ADD shaft beside the Non-ADD shaft on the bench, it appears that the Non-ADD shaft is 3-4 mm longer. All dimensions on the splined ends of the shafts appear to be the same (diameter, shoulder depth, etc) as measured with verniers.

Now, my questions are: Did toyota change the lengths of the driveshafts from the earlier models (it's possible that the wreckers sold me something that wasn't) And are there any other differences in the diffs from ADD to Non-ADD?

I'm not quite ready to fit a Trailgear kit just yet.

[leehamescort]

You can put an Non-ADD shaft onto an ADD diff but cant go the other way.

The ADD centre has needle roller bearings that support the axles, the Non-ADD centre has brass bushes.

I cant remember what clashes exactly but I've run the non ADD axle on the ADD centre without issue but tried to do the other and the axle wouldn't fit.

So remember if you break an inner axle in the bush, to swap it over you need to carry a spare bearing as well (they get destroyed when the axle breaks), with the nonADD you only need the seal as the bush usually survives with only minor damage.

Plug up the vacuum tubes and connect the ADD sensor wires together so the 4wd system thinks that the front ADD is connected and engaged otherwise it wont let the tranfer shift into 4x4.

catcha
Leeham

[-Nemesis-]

I just put the actuator in the right position so the axles engaged, then put a hose clamp around the slide so it can't move. Haven't had a problem for 2 years and counting.

I also switched to manual hubs and transfer at the same time. Transfer from non SR5 4Runner bolts on with the good old 4 position stick.

[Micky-Lux]

I haven't had a chance to check this thread for a few days - I've been paid to go 4wd-ing around Gympie in a V8 Cruiser!!.

Anyway's, I have the original diff centre here (the one in my Lux has an airlocker in it). Looking at both shafts on the bench, they both go into the centre OK. but it appears that the non-ADD one is about 3-4mm longer. The outer tube pieces appear to be the same total length.

I need to pull the diff out again (!!!) and have a look with the front cover removed and see how it all fits. If all else fails, I'll install the original shaft again and just lock the ADD up. I had that setup before, but I had about 1mm slop in the sleeve to locking gear bit, so the reason I went to the non-ADD shaft in the first place was to remove the slop, remove unwanted extra parts, and simplify the whole thing.

I'm off to the Cape at the end of next week (in 6 DAYS yee hah), so I don't have a whole lot of time to muck around with it...

[Struth]

I just put the actuator in the right position so the axles engaged, then put a hose clamp around the slide so it can't move. Haven't had a problem for 2 years and counting.

I also switched to manual hubs and transfer at the same time. Transfer from non SR5 4Runner bolts on with the good old 4 position stick.

Is that a gear driven transfer you're talking aout instead of the SR5 unit and is that mated to an R150 series?

Cheers

[Micky-Lux]

OK, further to this thread.. It's taken me a few days to do anything more.

I seem to have fixed the leaky diff now. Where I thought the driveshaft lengths were different, they appear to be the same when fully assembled. That is, if you put them side by side, the ADD one is shorter, but assembled, it is the same length, as there is a slight gap between the shaft that goes into the diff and the shaft that slides into that.

Anyway, I had a look at the wear pattern on the original bearing, and the new shaft is seated properly. What appeared to be the problem is that over time, a little dirt and water was able to get around the outer bearing race, and cause wear on the housing. Not much wear, but enough to allow seepage of oil.

The solution was to clean both surfaces thoroughly with prepsol, then apply some grey permatex (the high torque stuff), assemble the driveshaft into the diff, then allow it to cure for 5 hours or more before putting it back in the car.

So far, it hasn't leaked in nearly a week, where previously it leaked after a day or so.

This might help someone that runs into a similar problem in the future...

Cheers