How many u-joints to buy?

[trd_4runnin]

I'm going to be buying some u-joints for the runner with my christmas money and was curious on how many I need to buy. This is my first 4WD vehicle and the first time getting into the drivetrain part of it, so sorry if this is a stupid question. It looked to me like there were 3 on the rear driveshaft and 2 on the front, but the auto parts sites are saying 2 on front and 2 on back. Just wanted to make sure. Thanks in advance.

 

[fourwd1]

First question is why are you replacing them? It's very unlikely they all went bad at once.

Your front shaft has 3 (2 in the Double Cardan joint at the t-case and 1 at the diff) and the rear has 2 (1 @ ea end).

If you have a 2 piece rear shaft there is a carrier bearing in the middle.

 

[trd_4runnin]

Well basically I have a vibration while driving. It is noticeable to me all of the time, but it gets pretty bad from about 60mph-70 then dies off after 70. At any time during the vibration if I let off of the gas the vibration goes away almost instantly and it coasts out perfectly smooth. This lead me to believe that I have u-joint issue(s). I figured while I was replacing one I might as well just replace them all, since if one went out the rest would probably soon follow.

After my initial post I did some research in which I found out about the double cardan (which I thought was on the rear shaft by the way) and read that when those go out, the dealership just replaces the whole double cardan as it is pretty difficult to replace the joints in that.

After I read that, I decided I'm going to do some more investigating to try and figure out which u-joint, or u-joints, are actually bad and replace them as needed.

 

[shootmymime]

i am not sure how many ujoints you have but your vibration is deff the u joints

 

[DavidAlexander]

Trd, I put alot of info on Haddix's post on here and Yotatech. There were a few links on the yota tread to previous u joint problems too.

Just found this in my Toyota repair manual.

Test for Driveshaft vibration:
1. Drive vehicle and note engine speed at which the vibration is the most pronounced. Now shift into another gear and bring the engine to the same speed (rpm).

2. If the vibration occurs at the same engine speed regardless of what gear the transmission is in, the driveshaft is NOT at fault.

3. If vibration decreases or is eliminated when shifted into another gear at the same engine speeds, refer to the following.

4.Bent or dented driveshaft. Inspect and replace as necessary.

5. Undercoating or built up dirt, etc. on the driveshaft. Clean shaft thoroughly.

6. Worn Universal joint bearings. Replace the U-joints or driveshaft as necessary.

7. Driveshaft and/or companion flange out of balance. Check for missing weights on the shaft. Remove driveshaft and reinstall 180 degrees from original position, then recheck. Have driveshaft balanced if problem persists.

8. Loose driveshaft mounting bolts/nuts.

9. Defective center bearing, if so equpped.

10. Worn transmission rear bushing.


Maybe a wheel bearing, worn shock bushing, lug nuts that are not on right, loose mounted steering gear housing or loose steering components, or damaged idler arm. Those are if it is vibrating all the time no matter what the speed or gear. (can be better or worse dependent on speed)

 

[trd_4runnin]

Trd, I put alot of info on Haddix's post on here and Yotatech. There were a few links on the yota tread to previous u joint problems too.

Just found this in my Toyota repair manual.

Test for Driveshaft vibration:
1. Drive vehicle and note engine speed at which the vibration is the most pronounced. Now shift into another gear and bring the engine to the same speed (rpm).

2. If the vibration occurs at the same engine speed regardless of what gear the transmission is in, the driveshaft is NOT at fault.

3. If vibration decreases or is eliminated when shifted into another gear at the same engine speeds, refer to the following.

4.Bent or dented driveshaft. Inspect and replace as necessary.

5. Undercoating or built up dirt, etc. on the driveshaft. Clean shaft thoroughly.

6. Worn Universal joint bearings. Replace the U-joints or driveshaft as necessary.

7. Driveshaft and/or companion flange out of balance. Check for missing weights on the shaft. Remove driveshaft and reinstall 180 degrees from original position, then recheck. Have driveshaft balanced if problem persists.

8. Loose driveshaft mounting bolts/nuts.

9. Defective center bearing, if so equpped.

10. Worn transmission rear bushing.


Maybe a wheel bearing, worn shock bushing, lug nuts that are not on right, loose mounted steering gear housing or loose steering components, or damaged idler arm. Those are if it is vibrating all the time no matter what the speed or gear. (can be better or worse dependent on speed)

I appreciate you posting that information, and actually printed what you had typed on hadix's post so that I could refer back to it.

For those interested, I got under the truck and checked the play on all the U-joints. All the fronts seemed ok, and the double cardan on the rear seemed nice and tight too. The very rear u-joint seemed to have a nice amount of play in it. We spend a couple hours today replacing it and man was that thing shot. The new one is in and the truck drives out beautifully.

 

[shootmymime]

glad to hear that, so i would like to know how many miles you have, and or what would cause a u joint to fail?

what i could come up with was basic millage, or shifting from R to D with out coming to full stop.

 

[trd_4runnin]

glad to hear that, so i would like to know how many miles you have, and or what would cause a u joint to fail?

what i could come up with was basic millage, or shifting from R to D with out coming to full stop.

I have 115k on the truck. I thought that it was a little premature for a u-joint to go out, but I'm guessing the driveline angle changes due to the lift don't help much. Also, I offroad a decent amount. I used to do a lot of mudding. I try and stay away from the mud now, but there was no doubt plenty of mud caked on that thing a while back.

 

[DavidAlexander]

Nice, im glad you were able to fix your problem. Thanks for letting us know that was the actual problem and that the replacement actually stopped your problem. Success, yes!

 

[004Gunner]

I have 115k on the truck. I thought that it was a little premature for a u-joint to go out, but I'm guessing the driveline angle changes due to the lift don't help much. Also, I offroad a decent amount. I used to do a lot of mudding. I try and stay away from the mud now, but there was no doubt plenty of mud caked on that thing a while back.

I plan on replacing some u joints next week because I have the same problem. My mileage is around the same too. Did you have to use a press like the repair manual calls for? I plan on using a mallet + force, and possibly a bigger mallet with more force.

 

[trd_4runnin]

I plan on replacing some u joints next week because I have the same problem. My mileage is around the same too. Did you have to use a press like the repair manual calls for? I plan on using a mallet + force, and possibly a bigger mallet with more force.

We didn't have access to a press so we did it the old fashioned way ( I don't really know if this is the old fashioned way or not..) and used a socket that was a bit smaller than the u-joint caps and BFH to hit them out. Just make sure you don't damage the holes where the caps go in, or the flange things of the driveshaft. Try and take the drive shaft out if possible, and if you have access to a vise this would help even more. Let me know if you have any more questions, but it was a learning process for me. Maybe best to have someone experienced with u-joints help you. Everyone I talked to says they are easy, but I think all those people were lying lol.

 

[004Gunner]

Ok good to hear as that was my plan as well. I do have a vise and I also plan on removing the drive shaft. Thanks and hopefully mine goes as well as yours did