Low RPM vibrations after fixing U-Joints! Problems

My truck has had a vibration in 2nd and 3rd gear at low rpms even when climbing up a small hill. I dont know what the problem is but its getting really anoying and i know Toyota will over charge me just to look at my truck. I have just replaced the U-Joints, any suggestions would help.!!
Also, i have a small lift AAL(Add A Leaf) in the back 2.5 and a 2 inch spacer in the front.

 

Did you replace the center ujoint? Did you mark the drivelines so they went back together the same way they came apart? If not, that is your problem.

 

I replaced all three. But i did not mark anything i just put the shaft back in after replacing.. Could i get it rebalanced or something like that?

 

Did you disassemble the slip spline? If not, turn the shaft 180 deg at the center, and try it again. If you did have the slip joint apart, the the yokes on the same shaft have to be lined up with each other for proper phasing of the ujoints. And either way, yes, it could be reballanced by a driveline shop, but it's not cheap.

And, just to clarify, did this start happening after the new ujoints, or was it there before?

 

^^what Phil said. The driveline is balanced as a unit so it must be put back together as such. There are only 2 possibilities at the center ujoint, so try swapping them 180 as Phil said. If you didn't pull the splines apart, then that should return you to good balance. Normally all the grease zerks are on the same side for ease of maintenance. Hopefully you put them back that way.

 

Okay, so i disassembled the whole shaft from my truck, put it i n my bed and replaced all U-Joints. This is the second time i have done this.(not happy) but the vibrations went away the first time. Now their back and when its super low torque on the truck the vibrations happen so i let go of my gas peddle and they stop. Would this be my truck needing new rear differential fluid? Maybe, new automatic transmittion fluid. Im confused on the 180 degree turn?? and slip joints,splines and yokes.. Thanks for the help guys!!

 

The slip spline is the "expansion joint" in the rear section of the shaft, and on these trucks has a rubber boot on it with crimped on clamps, so you would have had to intentionally disassembled it. A yoke is the part welded to the shaft tube that the u joint fits into , or the flanged yokes that bolt to the diff, tranny... Since there are two possible ways to assemble the two sections of the shaft together, turning it 180 degrees, or 1/2 a turn, will possibly restore the balance if it is currently assembled opposite of how it was when the assembly was balanced.

I'm still confused though. Did changing the ujoints start the vibes, or is it just that it didn't cure it this time?

 

I'm confused too What do you mean it went away the first time? You didn't need to replace the Ujoints the second time. All you needed to do was seperate the center joint, rotate one of the shafts 180 degrees and reassemble. If you had separated the slip splines, then you also would need to get those back in line as they were originally. There are potentially 2 posibillities there that would appear right as well.

If you just repeated the same wrong procedure, then you'll get the same wrong result. You might have to just take this to a DL shop and get them to set it right. I'll bet they do this 2 or 3 times a day. I don't know why the damn shafts are not marked when they are assembled originally. That would make too much sense I guess

 

Sorry for the long wait on the reply guys.! but i have found and cured the problem! My truck now has 142,000 miles on it, never changed any fluids except for the oil every 4,000 miles... With that being said the vibrations were from the automatic transmittion fluid being super old! I replaced and flushed the system with another threads help making my truck now feeling like new!! I love the way it drives now without any vibrations and bogging down on the engine. From now on i am going to change this fluid reguarly(I also did the rear differentials). Now running synthetic oils which to me feel much cleaner and better performance all around!

 

i have 112,000 miles on my truck and just replaced all 3 U-Joints. That solved most of the problem but I am still getting a random vibration when accelerating in low gear. The vibration goes away after I speed up or slow down. I read something about rotating my drive shaft 180 degrees? Does it sound like the same problem you had?

 

Try a full flush on the automatic transmission fluid their should be a thread on "HOW TO". That's what fixed me up.. best of luck