Drive Train Vibration

[Michael Murphy 2]

Hello out there in Sport Trac Forum World,
I'm once again asking our seasoned Sport Trac owners another question about a vibration in my drive train.
About six months ago I started feeling a clunking sound when I did not come to a complete stop when changing from drive to reverse.
It didn't take me long to look under the vehicle and see that the center bearing for the split drive shaft was completely shredded.
So, instead of messing with it myself, I had a dealer put the new bearing in.
From that point on I started feeling a little vibration, not when changing gears....that was not it, it was only happening when I reached like 70 mph.
This all came to a head when I thought I would have it checked out again...but before I do, I would like to know if the dealer did reinstall the drive shaft correctly, would that cause the vibration. After some research, I learned that the tech could have not properly aligned the front section of the drive shaft with the rear section.
Someone said that this misalignment can cause vibration and actually make the transmission out seal leak.
Perhaps someone has some experience with this and some recommendations.
I do thank you for reading my post.
Happy Sport Trac - ing to you all,
Murph

 

[dvdswan]

The driveline is balanced like a tire is balanced. If you did put the driveline back together not in the same position (I don't know if it would be just 180* out like a u-joint or a splined like a slip joint, then it could be 1 to 10 depending on the number of splines). You will have a vibration if it is not in the correct balance position.

With that said, you have a couple of courses of action. I would replace your u-joints on the d/line anyway, but that is one. 2. take d/line to a d/line shop and have it rebalanced. 3. R&R the support bearing turning it until the vibration is gone.

 

[Michael Murphy 2]

Hi Dave,
Thanks for your reply.
I don't think I have ever heard of a drive line shop....is that basically someone who can rip apart the transmission and motor, or a specialty shop?
Is there any chance that the transmission is not correctly aligned?
What else would cause the vibration?
Would putting it up on a lift, putting it in drive and get the speed up to different points while someone underneath looks at what is vibrating?
So many questions!! LOL
Murph

 

[Michael Murphy 2]

...also, is there a video or photos somewhere that shows and explains, in detail how to check and realign the ST 2wd drive shaft?
I am curious.

 

[dvdswan]

There are shops that are strictly for drivelines. A good example to help is to check to see if the u-joints are all inline with each other.

Having a dealer replace the bearing, I would chance to say that it was done correctly, but not guaranteed.

As far as vibrations, bad transmission mount, broken engine mounts allowing engine to shift/tilt, u-joints, bent axles, etc. I would think the dealer would mention those if they were bad so they can make more money.



https://www.tacomaworld.com/threads/diy-replacing-driveshaft-center-bearing.515726/

Vibrations at 70 are usually with tires/wheels. Try rotating tires front to back and see if vibration changes.

 

[Michael Murphy 2]

Once again, Dave, thank you for your feedback.