xrayguy

I just bought my dad's 98 taco reg cab 4x4. He never really had it in the mud too much, and as a result never really used the 4wd. He can't remember the last time he had it in 4wd. I've noticed that one of the Aisin manual hubs only turns 1/4 of the way, the other one works fine. After reading this forum, I know an Aisin hub rebuild is in my near future. My biggest concern is this: once I'm able to lock both hubs, is it okay to go ahead and shift into 4wd and use it, or is there some other prep work I need to do to the front end components to insure I don't destroy it. I read in the owners manual that the hubs need to be locked and driven in 4wd at least 10 miles/month to keep everything in the front end lubed up, so this is why I'm concerned. Any help/advice would be appreciated for a newbie like me.

rworegon

Seems like changing the gear oil in the differential would be a good start...while you are at it, do the rear differential and transfer case too. Remember to loosen the fill plug before removing the drain plug.....you don't want to have the fluid drained out and then find you cannot get the fill plug loose.

taco_ted

I agree with rworegon, I changed all of the gear oil in my truck when I bought it and noticed an improvement with shift quality (I have the 5-speed) and overall smoothness. I have the auto-locking hubs so I can't speak to the hub issue, but if it fails to lock then having 4wd seems a little pointless. I don't think it will damage the rest of the 4wd system, if that's your worry.

xrayguy

My big concern was trying to use the 4wd without all those front end parts being lubricated, and just destroying it. I certainly can't afford to replace any of those components. Changing the gear oil didn't seem like it would be too hard to do myself. After reading and watching some YouTube videos the locking hub rebuild seems like a piece of cake, so I'll focus mainly on getting all that oil changed out and insure everything will work safely. After changing the oil out, is there anything I have to do to make sure everything gets lubed internally or is changing the oil enough?

xrayguy

So here's my dilemma. The owner's manual says to drive at least 10 miles a month in 4wd in order to keep all 4wd components properly lubed up. But you are also not supposed to engage the 4wd on dry roads. My question is what do you do when you don't have any slick, wet, muddy, off road terrain to drive on? Thanks for the help, because I'd really like to take care of my truck.

irab88

iTrader: (4)

what rig do you have?

you should be fine without driving "10 miles to keep things lubed". actually, i've never heard of such thing, and i've never done it (4wd works flawlessly every time)

if you want to, i'd say put it into 4wd without locking the hubs, unless you have auto-locking hubs, in which case i'd recommend you get some manual ones.

xrayguy

1998 taco reg cab 4x4 2.7L. I had read about the 10 miles requirement in the owner's manual, via the Toyota website. I have manual hubs, so I should be able to leave them in free, but shift into 4HI and drive as normal for a little while to keep everything lubed? Or should I not even bother with it? I'm about to try and change the diff, trans, t-case fluids so I wanted to make sure everything was nice and oiled up afterwards.

Birdbrain

Its honest to god in the manual, I found it at Reiters a few years back and my cousin and i used it as an excuse to go wheeling. so... Go wheeling!

Really, if your that concerned, go around and check and make sure she is all greased up properly, check the CV boots etc. Other than that, there's not much too it. I'm sure hundreds of people drive these trucks without using 4wd for 10 miles a month. God knows I don't, I just make sure its all greased up, generally when I change my oil.

Birdbrain

To get the diff to circulate the oil, I would just lock the hubs and go for a drive as that should spin the diff. The tranny will move the oil around just fine. As far as the T-Case, its probably not that big of a deal as the residual oil from what you drained will still remain and coat the chain etc.

xrayguy

Thanks!!! Here I was all worried that I'd screw one thing up trying to take care of something else.

Birdbrain

Np, but just FYI, you should have reposted this question in this thread:
https://www.yotatech.com/forums/f2/n...co-4x4-231094/

Im gonna advise that a Moderator merge the two threads?

xrayguy

That's cool. Thanks birdbrain!!!

xrayguy

So here's another question. I searched and couldn't find an answer so now I'm asking it here: does the factory skid plate have to be removed in order to change the front diff fluid? I'm thinking yes because obviously even see the plugs when I looked under it. You guys with more experience can save me some trouble, hopefully. Thanks in advance!!!

rworegon

Yes, the skid plate needs to come off.

xrayguy

Thanks. Fun times doing the front diff.