Cardiac

Forgive a noob. What is the advantage of manual hubs? I've read about guys doing the conversion here on YT, but I'm not getting why. How do the auto hubs work, and what makes them less desirable?

Flamedx4

The advantage to manual hubs in that you can unlock them for highway travel, reducing drag (maybe) and improving steering.

There were a few years where auto locking hubs were offerred, these were a disaster. They break. Back in the mid to late 80s all the hub manufacturers sold aftermarket auto hubs.. You might notice they don't anymore... An auto locking hub would lock itself with the torque of the axle turning when you go into 4wd. If you backed up it had to unlock then relock in the opposite direction. (This didn't always work properly.) Most of them simply broke if you were even a moderate offroader, and they broke halfway up that dangerous impossible hill or in the bottom of that canyon that you needed to climb back out of... Murphy's Law y'know...

In your '93 if you have ADD you have no hubs, so nothing will break there. Some claim there is an advantage to getting rid of the ADD and putting on manual hubs, but unless you're going rock crawling you're not likely to break the ADD mechanism. I've had all three types, and the ADD is nice - don't have to get out to lock the hubs or suffer with the wierd steering feel with the hubs locked in when I switch back to 2wd.

I'm thinking about going to manual hubs and keeping the ADD, then I can have the best of all worlds. Unlocked for less drag and better steering for highway use, hubs locked but having the ADD for convenient in-and-out of 4wd in the winter or on trails.

Cardiac

Well, I have manual hubs, and all I know is I hate getting out to lock them. I use the 4WD to get around in the snow, and that's all (so far). Can you clarify what ADD is? My thinking was since guys want manual hubs, and I want autos, that I could offer a trade. But of course, I want to understand the differences and advantages first...

Beautiful truck by the way, I just checked it out at the link in your sig.

SoCal4Running

I got rid of my auto last week and replaced them with some manual ASIN hubs because of 2 reasons.

First reason I replaced them is becasue when the truck was on jack stand during the motor rebuild I spun one of the front tires and noticed that it turned the axle shaft. I thought WTF that cant be good for gas milage. So I spun the other side and it did it too. Either there is some built in drag in the Auto hubs or mine were broken.

The second reason I relpaced them was because there is no 4wheel drive in reverse and this I found out on a steep decent off-road where I needed to back up.

AW1090

Cardiac...do you have auto hubs or add? There's a diff. between the two....ADD is basically like having a manual hub that is locked all the time. The reason I switched to manuals is that I'm planning on lifting my truck and when you do that you put more stress on the cv's. I think when you have manuals then you can unlock the hubs and reduce the stress. I think drag, steering, and slight gas improve are also in there. I'd keep the manuals cause they are usually wanted and they're not that difficult to deal with when needing 4wd. When it gets to winter just switch them to lock, leave them all winter and drive...whenever you need 4 wheel just use the lever in the cab. Then summertime comes just unlock the manuals and drive in 2 wheel for the summer. Sorry for the long post....hope this helps.

roger

IIRC, ADD stands for 'Automatic Differential Disengage' or something of that sort. Basically it's like having your hubs locked all the time. The axles are spinning but the transfer case is not engaged, so no 4WD.

BTW, it's OK to drive with your hubs locked but in 2WD. It's essentially the same as having ADD. That way you can just shift it into 4Hi or 4Low without getting out of the truck. This will cause more wear on the front drive components, but so does ADD (one reason why manual hubs are superior in some ways).

Corey

iTrader: (1)

1. Auto hubs are bad.
As mentioned, they do not work in reverse, that is how you disengage them.
Not good when backing up on a trail.
2. ADD is nice, but also as mentioned if you lift the rig, it puts more stress on the front end from having the CVs turning all the time.
3. Manual hubs are the holy grail, do not get rid of them.
Many of us switch from ADD to the manual hubs to get better gas mileage and less wear & tear on front end components.

kyle_22r

the main advantage of running manual hubs on an IFS truck is because with a suspension lift, they put less wear on your CVs, since the axle shafts are only turning when the hubs are locked

Darx

I recently converted to manual hubs on my Taco. The Tacomas have it rough since they need to replace not only the hubs but the spindles and cv axles as well.

My main reason for doing this was lift. To get around the wear and tear as has been mentioned you just unlock the hubs when not offroading. I got my parts off of a 2000 Tacoma.

rimpainter.com

OK, now I am really confused. I have "4WD" in reverse with auto locking hubs.

AW1090

96 runner....right cause you have the "ADD" and not the auto hubs. Check this out
http://www.4x4wire.com/toyota/tech/autohub/
It's a pretty good explaination of the three hubs available

rimpainter.com

Thanks Andrew.

AW1090

Welcome.... it's all about the team

mike_d

you're right. that auto hubs require spinning of the front axle to engage in forward. and then when you back up they disengage. but if you keep backing up they have a second reverse lock mode. so when you switch directions, it goes lock-unlock-lock. which can be a real pain if you need to rock the truck to get unstuck.

fiveofeen

very cool thread, i had been wondering about this. everything about the manual hubs seemed good to me except climbing outta the truck to lock em' (wonder why americans are so fat) guess i have the add style. now i only have a reason to swap if i lift the truck.

Flygtenstein

ADD has not one darn thing to do with your hubs. Not a bit.

You can have ADD with drive flanges or you can have ADD with manuals hubs.

My 95 had and still has ADD. I have replaced the drive flanges with manual hubs to save some wear and make braking an axle less alarming and in need of immediate attention.

An auto locking hub is not the same as ADD and is not the same as a manual hub.

Albuquerque Jim

Ditto

Darx

Yeah same here. I'm still ADD but have manual hubs, spindles and CVs. MEaning I can run around with my hubs locked and that would be like having ADD since I can jsut push the button on my second stick for 4x4.

Jboy

Too much lift and ADD hubs do not match. Your just looking at replacing cv boots all the time and possibly cv joints. Both are expensive if you can`t do it and a waste of time if you can do the job. Do it once and replace those hubs with MANUAL.

Cardiac

Wow, a windfall of replies. You've all convinced me to keep the manual hubs and cope with hopping in and out. I just remember last year when I thought I could get out of the driveway in 2WD, and discovered I couldn't. So I'd hop out and lock the hubs, and drive out in 4WD. Then I'd hop out again and unlock them. I know I could drive with the hubs locked, but I know it affects fuel efficiency, makes for unnecessary wear, and it makes more noise. I'm also a fan of simplicity. I did a brake job on it three weeks ago, and the hub and everything all comes apart easily.

Thanks for sharing your knowledge. If anyone needs to know anything about the SW20 MR2, I'm your man!