Keep hubs locked all the time....

Locking the hubs on a man hub set up will make the entire front drive train spin, everything. Open or locked.

 

^^^ This. The only point of disconnect in this situation, with the lever at the 2H position, is in the t-case. Everything from the front wheels to inside of the t-case spins, with the only point of mechanical disconnect being inside the t-case. This was my observation years ago in that truck.

 

1995-2000 1st gens with manual hubs (called free-running hubs in the owner's manual) do not have ADD.

Anyway, I still haven't found where in the manual Toyota forbids running above 50 mph with the hubs engaged in 2H. Section 1-6 of the manual says you can shift from 2H to 4H at up to 25 mph after the hubs are engaged. The limit for shifting from 2H to 4H for models with ADD is 50 mph. http://www.toyota.com/t3Portal/document/om/OM35751U/xhtml/OM35751U_OM0006.html?locale=en

 

x2, and some more.
The 50 mph thing with ADD is just to ease the load on the transfer case 4wd syncro. With ADD you can shift into 4wd at any speed but at 50 and above you can really feel the load on the syncro as it labors to spin up the drive shaft/ring and pinion gear as well as reversing the (opposite spinning) rotation of the pass side, side gear and intermediate shaft.
Some early 4Runners and the late ones with a third "center diff" can run in "all wheel drive mode" at any speed, wet or dry, all day long.

 

I must have read that years ago and have mentally held onto that as Toyota's 4WD speed limit recommendation. You're right - I just looked in my manual. 50 mph is specified as the shifting speed limit only.

So I'll dial it back from saying it's Toyota's recommendation and just say it's only my opinion, based on my experience. I think I'd still argue that if you're hitting 50+ mph, you don't need 4WD and shouldn't be exposing the front driveline to more W&T than necessary. It doesn't take much effort to lock and unlock those hubs, and your truck (and gas mileage) be happier for it.

Carry on...

 

Actually its you that are incorrect sir!

Trucks that came with manual hubs do not have the ADD system so everything spins from the axles all the way to the T-case when the hubs are locked unlike with the ADD system where just the spider gears spins since the passenger side axle get disconnected.

 

I stand corrected.

In my defense, my experience is with ADD but my good friend has manual hubs with an auto-locker on his tacoma. I based some of what I said on what I thought I knew about his truck.

And he told me I was wrong too after I wrote that. Sorry about adding to the confusion.

I was trying to agree with you and confirm that on 1st gens with ADD (mine) the front driveshaft does not spin when in 2hi, same as your 2nd gen.