JGordon

Howdy folks - I've been lurking for a few months and picked up a lot of good info, but this is my first post.

I picked up a 1992 Toyota 4runner with 214,000 miles on it back in March. It's v6, 4x4, 5 speed, and runs pretty good though it needed some miscellaneous work when I bought it. (new windshield, new brakes all around, new hubs, got the rear speakers working, got the antenna working, got the drivers power window working right, new gas cap, new steering wheel cover, new floormats, and a few things remaining to be done) I don't drive it too much (it's a bad weather/off-road/camping beater for me) so I've only put about 1,000 miles on her.

It didn't have any hubs on it when I bought it (and obviously didn't have working 4x4, but the previous owner swore it worked just fine, but he had to take the hubs off for some unknown reason), so I picked up some Warn manual locking hubs. With the hubs in 4x2, the truck handles just fine at highway speeds. With the hubs in 4x4, whether 4x4 is active or not, she gets a pretty wicked shimmy from the front end beginning at about 40mph, pretty bad by about 50 and I've been too scared to go over 60. Any ideas what it could be?

I've seen some other threads that recommend checking the U-joints for play. This is the first time I've worked on a 4-wheel drive, so I'm a little new to the terminology. Are the U-joints what connect the front driveshaft from the tranny to the front diff? How do I check them for play? I got under the car and tried to move things around, but didn't find anything loose.

abecedarian

May I ask...
...what type of roads are you driving it on, at 40+ mph with the hubs locked?

abecedarian

well if you'd have been driving down the atlanta highway, you'd have known the tin roof was rusted.

CJM

You need to remove the front driveshaft, then check the u-joints (you will see them, they look like universals joints for sockets) and if they dont move easy as pie its time for new ones.

YOur not supposed to be going 50mph + in 4wd anyways, I surely hope its on dirt roads too. Pavement and 4x4 = no!

JGordon

I'm not driving in 4x4, I'm driving with the hubs in 4x4 but the 4x4 shift lever in 4x2. So no power is going to the front wheels, but the front diff is still turning. With the hubs in 4x4, but the shifter in 4x2, this is essentially the equivalent of driving the truck with the stock hubs on and 4x4 disengaged. The aftermarket hubs merely give me the ability to disconnect the front diff totally, so that the wheels turn freely.

This isn't a huge deal because I can always get out and manually switch the hubs before I engage the 4x4 shifter, but sometimes it's nice to have the "shift on the fly" capability that locking the hubs in 4x4 gives.

CJM

Oh ok, you have the hubs locked but not in 4wd. Sounds like your u-joints are bad or the shaft is out of balance.