Slip yoke thump - again

Hello all. I'm a newbie but I've searched and read MANY TW threads on this and can't get a clear picture of where to attack this. My 2005 extra cab 2wd has the classic thump that seems to be a slip yoke issue. I did the cheap ubolt axle wrap mod on the leaf springs first, but that didn't fix it. My issue is that I can't tell exactly where the slip yoke is, and I don't want to take anything off until I do. Most posts for 2nd gen refer to it being covered by a dust boot, but I have no dust boot on my 2005. Just the two solid shafts connected at the bearing. One post mentioned "thinking" that the yoke is where it meets the transfer case, but that doesn't seem right. I'm "thinking" the slip yoke is either where the rear shaft connects to the differential, or at the back end of the front shaft where it joins the rear shaft at the bearing. I saw the info on the best lube to use, so I'm ready to go once I figure out where the dang thing is. Hopefully it's an easy answer - much appreciated.

 

There is the slip yoke on the 2wd trucks, and the slip joint on the 4x4's.

The slip yoke is at the transmission, the driveshaft actually plunges in and out of the transmission.

The slip joint on the 4x4's is after the center u joint and has the dust boot... its setup this way as you have a transfer case with a fixed flange.

 

Ah. That's just what I needed. Thank you! Any tricky aspects of the job, or is it as relatively straightforward as it seems? Thanks again.

 

Remove the driveshaft and inspect the internal splines of the yoke with a flashlight .
You will lose fluid when removing the driveshaft
The splines inside the yoke are softer than the output shaft splines on the transmission as its cheaper to replace a yoke over a transmission output shaft .
Are you automatic or manual ?
If you have a manual transmission , you can get away with adding spline lubricant to the inside of the splines but if you have an auto , I would be certain that your spline lubricant is compatible with the auto trans fluid .
If the inner splines are worn out , we usually replace the yoke .

 

Thank you. It’s an automatic. That raises the question, though, of whether I can expect any improvement from hand lubricating the yolk. If it connects at the transmission, isn’t it lubricated with transmission fluid?

 

I think your goal here is inspecting the splines inside the yoke for wear .
As a test , you can add some lube to see if your clunk goes away but you are correct , it is lubricated with transmission fluid and the trans fluid will quickly break the lube down .
The splines on the yoke are common for wearing on all Spicer driveshafts across all models of vehicles .

 

You’re a huge help. I will get cracking on it.

 

I have a 2017 TRD Sport with auto trans and the thud when slowing down to a stop can be nasty. I'm very much interested in this discussion about the slip yoke/joint but still a bit unsure of how this joint can act up in a manner that causes a thud. I've read the posts on axle wrap but find it difficult to imagine that when the auto trans is shifting down into first gear it would cause appreciable axle wrap. The dealer has not been of any help; they make it sound as if I am the first Taco owner who has mentioned this.

Some have suggested that a bit of weight in the back can help eliminate the thud. Would this be because the drive shaft angle is slightly affected by the extra weight?

By the way, I have torqued the U-bolts to 90 ft lbs; this has not made a difference. I've also tried beefier U-bolts at 90 ft lbs and again no difference. I have no lift, the truck is stock.

 

You are posting in a 2nd gen thread .
Not that it matters , we all use spicer components to make up our driveshafts .
What you can do is remove your slip yoke and apply the special lubricant and road test to see if the issue goes away .
Whats your mileage ? Are you still on warranty ?
There are technical service bulletins to help with your issue
Have you checked your transmission fluid to be certain its full ?
https://www.tacomaworld.com/threads...be-low-on-fluid-directly-from-factory.405642/

 

Dutchy, I’m the OP. As stated above, this is a second generation forum and I don’t know what design elements apply to a 2017. However, it turns out that my issue was low transmission fluid! I had taken it to a shop that works on slip yokes, and the first thing they tested was the transmission fluid. It’s a sealed system so I couldn’t check the level, and they had to put it up on a lift and follow that specific procedure. They said the fluid was full. I note that I didn’t question didn’t question this, because there have never been any leaks where the truck is always parked. So they concluded there was something wrong with the transmission itself unrelated to the yoke and referred me to another shop. The new shop then checked the fluid level, said it was low, topped it off, and everything has been fine since. Bizarre.

 

What mod would that be? I don't think I've seen this. Link to it?

 

Mine is a manual 4x4 access cab. I let the thump go on for too long.. finally took it in to get U-joints and center bearing replaced. Was just shy of 600$. They put it together, I drove it and at 40mph it vibrated like a paint shaker. The slip yoke wore in such a way with the other parts it was out of center by about 1/4 inch. Had to get another whole driveshaft. Luckily the shop credited me the entire bill towards a new one. Now it’s better than ever.