Manual Hub Conversion for the 1st Gen Tacoma & 3rd Gen 4Runner

Haha. Figures!

 

Hey Everybody,

It is amazing how much attention these manual locking hub threads get, which is good because there is a lot involved in doing the conversion as you will see when you read Dave's (DJBI) posts, and he did an amazing job reengineering the front axle of his Tacoma to accommodate manual locking hubs. Dave is spot on accurate as to his reasons why manual hubs are advantageous over the auto locking ADD system especially now that even the newest of the first generation Tacomas are approaching fifteen years old. Manual hubs will age much better hands down than the auto locking ADD system. Please don't think if you have a first generation Tacoma with ADD that it is going to break tomorrow because that is by no means going to happen especially if it is not abused. The only reason why ADD was engineered in the first place was because Americans wanted convenience, and Toyota trucks had to compete with the convenience of sport utility vehicles in order for Toyota to keep selling trucks in the United States. As a result of this convenience, Toyota could charge their customers more for Tacomas, which, as we all know, is very advantageous for Toyota.

For all of you considering doing this conversion, remember this conversion requires a lot of time, effort and parts. These first generation Tacomas are now very old. My advice to all of you considering this conversion is to wait until something breaks on your ADD Tacoma first before converting the entire thing to a manual four wheel drive system. For those of you that don't have the patience to wait for equipment failure, make sure you have all of the parts together before moving forward with this conversion project. The used stock Toyota parts are also getting more difficult to come by especially since the factory terminated all manual hub four wheel drive Tacomas after 1999 or 2000. Anything between the years of 2001 till the end of production 2004 Tacomas will all have the ADD system.

Good Luck to Everybody,
Paul

 

Thanks, @TacomaJunkie8691, I tried to compile all of the pertinent information about this swap into one place so it's easier for the next guy. I had to bookmark and re-read threads from all over the interwebs to figure it out.

With the right parts and tools on hand, the job can be done in an afternoon. It took me about 6 hours total including new brake pads/rotors, axle seals, and taking the passenger side front suspension apart a second time to replace the hose-clamped ADD intermediate shaft with the non-ADD intermediate shaft. Now that I know exactly what to do, I could do it again in 3-4 hours. I'd consider it an intermediate skill-level job comparable to installing a lift kit.

I do not understand the point of the ADD setup. Both CV axles, the front differential and front driveshaft all rotate whether it's engaged or not. 4Runners with full-time 4WD have no ADD and get the same MPG as 4Runners with part-time 4WD/ADD. Even the V8 4Runner with full-time 4WD is rated at 1 MPG less than the V6 4Runner with part-time 4WD/ADD. Looking at FJ Cruisers, the 6 speed manual/full-time 4WD version is rated at 1-2 MPG less than the automatic/part-time 4WD version, but it is also geared lower.

On the 2nd gen Tacoma you could install a non-ADD intermediate shaft from a manual FJ Cruiser or AWD 4th gen 4Runner, and a J-shift transfer case from an automatic FJ Cruiser. That would eliminate the pesky ADD actuator and annoying automated transfer case, lose electronic parts and gain instant engagement from 2WD to 4WD. I highly doubt it would affect the fuel economy. At least one TW member has done this: https://www.tacomaworld.com/threads/how-to-deleting-add-system.427258/

Of course the best solution is manual hubs. I don't consider it inconvenient to turn in the hubs if snow is in the forecast or I leave pavement. I can still shift in and out of 4WD as needed with the transfer case. But it's extremely convenient to unlock them and cause zero wear on the front axle when I don't need 4WD.

 

@Honey badger look here

 

Did you get yours done yet @Buck18?

 

Thanks for your help!

Now I have the option to buy a manual hub axle shaft and intermediate shaft and swap it to my 1996 4Runner Vacuum ADD diff. Would it be better to swap the manual shaft or just keep my vacuum shaft?

I just don't want to cause excess wear or premature damage or anything.

 

Yes I did. I did it the weekend after our phone conversation. Turned out great. Thanks for all your research and this awesome thread !

 

You'll have to remove the intermediate shaft either way, so might as well use the non-ADD one. Having manual hub components will cause less wear, not more, because when you're in 2WD with the hubs unlocked only the wheel bearings are turning and not the whole front axle. If your truck is lifted you will also eliminate the dreaded front diff vibration.

 

DJB1--A man after my own heart. Your introduction to this great write-up reminded me of my youth (which was definitely before yours!). I grew up with manual locking hubs and like them for the same reasons; some aesthetic and some practical. Down on my uncles' country place we had a couple of old Willy's and a '68 Bronco with three on the tree and its manual lockers. My white '85 4x4 with Glasstite shell was a dead ringer for the one below your family Suburban. Loved that truck. Don't have to do the conversion because my new toy (Toy) is a '96 Taco with manual lockers. Reminds me a lot of my '85 and am looking forward to making it mine.

 

So are the inner cv shafts the same on auto and manual cv's? I'm looking to replace my front suspension along with some cv's that use the inner cv shaft that goes into the diff from an ADD cv and dana hubs that are manual. Basically I have a spare ADD diff that I'm going to tear apart and send to ECGS for a locker and I want to figure out if it's worth sourcing a manual diff instead - what do you think?

 

Sub'd because of that awesome Sub (Suburban that is)!

My friend's dad had a late 1970s or very early 1980s Suburban (forget whether it was a 2WD or 4X4) with a 4-barrel 350 and dual glass-packs! It was his spare throw-around "down the shore" vehicle he used for hauling family and towing a boat.

When this old Burb was 20-25 years old, it still ran and drove great, and the A/C was still blowing ICE COLD, but he had to
scrap it when he could see pavement through the floorboards and it would no longer pass inspection!

 

As long as it has air-conditioning and intermittent wipers, I'd totally buy one!

 

So as I understand you can have a push-button transfer case and manual hubs and still shift "on the fly" with the 4HI button on the shifter? I always thought you had to use a j-shift transfer case with manual hubs.

 

No, you don't have to have a j-shifter. The addition of the manual locking hubs on w/ ADD diff allows the axles to not rotate.

Less wear and tear. That is the route I was going until I found the non ADD front diff.

 

And you still have to lock the actuator with a hose clamp right? So if I have the manual hubs in lock and shift out of 4WD into 2HI the truck would be in true 2WD?

 

Right, still have to lock it.

 

If you watch one of @Timmah! videos he worked on a 4runner that had ADD. They swapped out the ADD spindles and axles for aisin manual locking hubs and axles. Still kept the ADD diff.

 

Tyler, could you hook up a non-add clamshell to an add tube and have it be the same thing as a fully functioning add diff? I don't think I'm going to find a manual tube like you could so I'm considering taking apart my spare add diff to send out to ECGS and buying a non-add diff in the meantime for the tube. My question is if I'd be able to put the spare pieces together for a fully functional add diff that I could sell...

 

Yeah I watched that video when I pulled my own diff out of a Limited 1996 4Runner. It was an ADD diff but I was lucky to be able to find a manual hub axle tube and intermediate shaft to swap on. I'm creating a PreRunner 4x4 conversion writeup and I'm trying to cover all my bases.

I tried the screwdriver method, didn't work. I had to hammer the ADD axle stub out of the ring gears with a pry bar. Gave me a chance to confirm it was 4.30 by counting the ring and pinion.

 

I'm getting there. Gonna take the truck onto the highway and record rpm and mph, swap e-locker w/case and record the same.