U joint lasted a week.
 

I put the u joint in, the very back one, and it's already bad. And there is up/down play at the sleeve. Do I need a new drive shaft?

What kinda angle is your driveshaft at? If it's super sharp you will eat through u joints. Give us more info about the lift (if you have one).

It's lifted 3 inches. Doesn't look like too drastic of an angle, though.

If you don't have a diff drop, get one. A 3" lift puts a lot of strain on the driveshaft.

I don't have the front drive shaft in right now. I took out the diff drop, by the way. The diff drop helps the cv's, but screws up the driveshaft geometry.

Read this:
http://www.4crawler.com/4x4/CheapTri...line-101.shtml

Your 3" OME lift isn't why your new U-joint went bad again. Tons of people have 3"+ lifts without driveshaft problems. If anything, a 3" lift might seal the deal on an already worn out factory U, but a brand new one should last several years. I've got 4" of rear lift, 208K and I'm still on all my original Us with no problems.

The diff drop won't help the OP's issue either since it's his rear u-joint going bad. But on that note.. The front driveshaft on an IFS like ours stays at the same angle regardless of how much lift you have. This is because the front diff stays stationary (it's attached to the frame like the t-case is).

What scottishb said about the diff drop putting more angle on the front joint of the driveshaft is true - it increases that angle a little while alleviating some of the angle on the CV axles. But, I don't agree that the trade off isn't worth it. The front DS only turns when your in 4x4 and it has joints also. The slight angle that the diff drop puts on the front DS's U-joint isn't going to harm anything. Those joints can handle a lot worse angles than that, especially on a front DS that is hardly ever used (compared to the rear). The CVs on the other hand, are a lot weaker than a DS with u-joints. Alleviating the CV angles a little bit is worth it because they break all the time. I've never heard of anyone breaking a front driveshaft/u-joint because of a diff drop.

I think you have a DS issue OP. Maybe the slip yoke is seized and it's hammering your rear U-joint.

With the silly ADD, the connection is in the diff up front. So the DS is spinning all the time. Not necessarily at the same speed, but it still spins. The only vibes I get up front are from the cv boots scraping.

And, back to the rear. I'm thinkin' seized slip-yoke too. So went out there and squirted like a whole tube o' lube in there, but I'm still getting the up/down play at the yoke. The up/down play screws up the in/out.

Maybe I just got a bogus u joint. Probably shoulda went "Toyota" there. I thought Napa had decent parts. Guess not. The stock one that came out had crusty needle bearings, and only 3 of the four ends had lube going to them. The other was bone-dry. But there was no play.

The front driveshaft doesn't spin in our trucks when in 2wd. The back tires push the front ones, which turn the CVs, which turns the spider gears - all passively. But the spinning ends there. The ring and pinion and DS stay stationary in 2wd and are only turned by the t-case being in 4x4.

Napa parts are good. The chances of the new U being bad are very tiny. Something else is causing the U joint the go bad IMO.

^However the chances of premature failure due to installation error can be high.

If you do it right, your expensive OEM or your cheap $10 bucks u-joint will last for years. If you do it wrong it will fail almost immediately like the OP.

I see a lot of ppl complaining about quality of u-joint, or even other aftermarket products, from local store as being crap. I believe the poor installation is the problem not the U-Joint itself. The installation is quite critical if you have improper tool and don't have a clue on how to re-assemble it.

Why was it replaced? Vibration, break apart, ... ?

i would first make sure you didnt spit out a c clip, then if they are in there and the internal style after installing relax the joint in a vise with a hammer to make sure there is no binding. second when you pull it out make sure you didnt lose one of the little needle bearings. and lastly when buying a new one get a greaseable one or drill out non greasable one and add a zerk. i toasted a joint when the end of my pinion was touching the back of the flange and when i bolted it down it distorted the ears ever so slightly to cause a drag and bind on the needle bearings, it lasted 4 days driving 60 miles a day

So I got down there, let the lady put it and drive. Using a steady hand, I let the DS ride my fingernail as it went around. It was smooth by the rear pinion, but got worse as I moved towards the cardan joint. It probably moved my fingernail like a 1/16". Tranny pinion was smooth. Excuse my primitive ways!

Is the cardan joint supposed to be smooth like the rear u joint should be?

I believe that's the main key to the installation. When you press it the caps, youll expect bind it(the cross touches the cap) to get the C-clip in. Relax the joint by hittin the cross to move the caps move further out. The joint should be buttery smooth.

Are you saying that the grease-able ones wouldve saved the joint?

no but you can grease them once in a while and they last longer if you stay on top of it. and to solve my toasted one i had to shave just a little off the end of my pinion gear. all the greazse in the world wont save a binding joint. good luck and by cv do you have a 2 piece rear shaft? im confused when you say it was smooth at the trasnny and diff but not at the cv.

I've got the 2-piece driveshaft. As it spins, both pinions look smooth, but by the cv it sorta wobbles a little. I couldn't see it, but I was holding my finger about a 1/16" away and it started to nick my fingernail.

I need to find a driveline shop.

You shouldn't have a 2-piece driveshaft if you have a 4Runner. It should have a Double-cardan joint at the Tcase, and a single U-joint at the diff. Thats a one piece driveshaft (one continuous tube between the U-joints) An Xcab Tacoma will have a 2 piece (unbolts in the middle, and uses a carrier bearing)

I would just get a new driveline from a wrecking yard, and be done with it.

My mistake! I thought the slip yoke meant that it was two piece. Soon as I cough up the money I'll get a new one.

hey death cougar what year did they start putting double cardan joints in the rear?

Not to insult the OP at all but how did you install the new one? And how easily did the old one come out? Only reason I ask is that I just did my u joints on the rear drive shaft. The rear most one broke 2 caps while trying to press them out. (Actually rented a press for it to do it the "right way") Finally gave in and went to a shop to have them pressed out and new ones pressed in. U joint replacement itself isnt too bad but after a lot of miles it can get more complicated.