Another 80 Series Vibration Thread (1 Viewer)

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After an exhaustive search through as many vibration threads as I could stomach, I think my situation is a little different, but please point me in the right direction if I'm wrong.

So the situation: My 80 is a mostly stock example, factory wheel size, OME stock ride height replacement suspension (which advertises a 0.25-0.75 inch lift), rebuilt the knuckles last spring, new wheel bearings, and mostly new bushings with the exception of the radius arms.

Before the holiday, I started to get a nasty vibration from 25-40 mph. Had the tires rotated and balanced as a sanity check, but it made no difference. Got it in the shop to replace the u-joints on the front driveshaft. Initially it felt great, but after about 25 miles, it started to feel rough at 70 mph, then maybe a mile or two later the brand new u-joint at the front differential broke (at 70 mph, in traffic, at 6:00am). One of the bearing caps was missing, but the driveshaft was connected. I limped it off the highway at 10 mph; any faster was quite shaky. Had it towed back to the shop.

The shop claimed the yokes were out of alignment which is what caused the second failure. They realigned it, balanced it, and installed new u-joints again. Then after a 20 mile test drive, they sent me on my way.

Again, it felt good initially. I decided to take it on a highway drive over the weekend to regain my confidence which ended up having the opposite effect. I did an 80 mile round trip drive on a 65 mph highway that has sections with a 4-6% grade. On the downhill bits, I was getting a rumbling at around 70 mph. Now, it's pretty much always had a slight rumble at highway speeds, but this was noticeably worse than before all this happened, although not quite as bad as before the u-joint failed a few days before. At this point, it's still smooth at all other speeds and it's smooth at 70 on flat ground, but I decide I'll keep it off the highway until I can do some troubleshooting. I'll note that I inspected the driveline multiple times and nothing looks out of the ordinary.

Fast forward to yesterday, on the way home from the grocery store I start to notice that low speed vibration coming back.

So to recap, replaced u-joints, one came apart 25 miles later, balanced driveshaft and replaced again, noticed off throttle vibration at 70 mph, and now feeling a 35 mph vibration coming back after about 130 miles since the second set of u-joints. All vibrations are very noticeably coming from the front of the car.

I have every reason to believe the shop doing the work knows what they're doing. They specialize in old Land Cruisers, but I'm not ruling out workmanship issues. That said, I'm starting to think they're mistaking the u-joint problems as a cause, when they're really a symptom of some other problem, or that the u-joint failure caused some collateral damage

So finally! My questions! Is it possible for u-joint problems to be caused by something else in the driveline? I.E. T-case, pinion bearing, etc? Can worn radius arm bushings be worn enough to cause pinion angle issues? Could the u-joint failure at 70 mph have damaged something in the driveline that's causing the increased vibration? If so, what parts should I be looking for damage to? I'm planning to pull the front shaft tomorrow just to really make sure the problem is coming from the front; is there anything I should be looking for while I'm in there?

Thanks in advance.
 
What year is your truck?

The front DS needs to be 90°out of phase and the rear DS needs to be in phase.

The slip yoke on BOTH DS needs to be at the front of the vehicle. (Front is at differential, rear is at transfer case)

A worn out slip yoke could cause this.
A worn out or loose pinion bearing could do this.

What brand of u-joints did they install?

There are supposed to be different thickness locking washers to properly set the u-joints in the center of the yokes. If they are too thin, they caps will be loose and come apart.

Having a u-joint fail in 20 miles is a workmanship issue. They should be using a press to install these, not a hammer.
 
What year is your truck?

The front DS needs to be 90°out of phase and the rear DS needs to be in phase.

The slip yoke on BOTH DS needs to be at the front of the vehicle. (Front is at differential, rear is at transfer case)

A worn out slip yoke could cause this.
A worn out or loose pinion bearing could do this.

What brand of u-joints did they install?

There are supposed to be different thickness locking washers to properly set the u-joints in the center of the yokes. If they are too thin, they caps will be loose and come apart.

Having a u-joint fail in 20 miles is a workmanship issue. They should be using a press to install these, not a hammer.
Great input, thank you. Truck is a 96, parts were Toyota. I'll check the phasing and orientation in the morning and report back.
 
On top of the above, get yourself a CDL switch if you don't already have one, lock the center, remove front shaft, and drive around for a few days. If vibration goes away, you have something there. Or if vibration is still present, you can rule out the shaft, although that seems less likely.
I actually just learned about that mod when I was reading vibration threads. I was planning to just put it in low and pull the fuse, but with all the stuff on that fuse, I may not be able to do the 70 mph test drive I need.
 
As @BILT4ME said, the front driveshaft comes from the factory out of phase. This is almost unique in the automobile world (I have heard of one other vehicle that uses this configuration, and it was made in the first half of the last century, IIRC) so many driveline pros will argue that it isn't right. For a lifted truck it almost doesn't matter if it's in phase or not because the angles are wrong for either config, but if your truck is at stock height you should definitely have the factory config. You could should print the FSM page that clearly shows the phases of the two driveshafts and show it to the driveline shop.

I'd find a different shop, personally, or at least convince them to put their best tech on it. The failure of the u-joint is likely on them- either they did something wrong when they installed it, or there's something wrong with the driveshaft that is causing the failure, although the speed of the failure after the replacement suggests a little of both: there is a problem with the shaft causing stress to the u-joint, and it was improperly installed and so failed quickly. Like @BILT4ME I would also be suspicious of the slip yoke (which any good shop would have assessed) and possibly look at the transfer case output bearing and the diff pinion bearing. The slip yoke is the more likely culprit though, by far.
 
As @BILT4ME said, the front driveshaft comes from the factory out of phase. This is almost unique in the automobile world (I have heard of one other vehicle that uses this configuration, and it was made in the first half of the last century, IIRC) so many driveline pros will argue that it isn't right. For a lifted truck it almost doesn't matter if it's in phase or not because the angles are wrong for either config, but if your truck is at stock height you should definitely have the factory config. You could should print the FSM page that clearly shows the phases of the two driveshafts and show it to the driveline shop.

I'd find a different shop, personally, or at least convince them to put their best tech on it. The failure of the u-joint is likely on them- either they did something wrong when they installed it, or there's something wrong with the driveshaft that is causing the failure, although the speed of the failure after the replacement suggests a little of both: there is a problem with the shaft causing stress to the u-joint, and it was improperly installed and so failed quickly. Like @BILT4ME I would also be suspicious of the slip yoke (which any good shop would have assessed) and possibly look at the transfer case output bearing and the diff pinion bearing. The slip yoke is the more likely culprit though, by far.
Thanks, I'll check the phase for sure. Unfortunately the weather didn't permit this morning. Would a loose TC shaft bearing or pinion bearing be pretty apparent with the driveshaft off?

As for the shop, I really want to believe they know what they're doing. They're literally a Toyota 4x4 shop that specializes in Land Cruisers. After the u-joint failure, they fixed it for free and paid for the tow without question, but they also gave me a story that implied the driveshaft was assembled wrong by a previous shop. Thing is, I've owned it for four years, my dad owned it for the previous 20 years and we both kept all our service records. So if their story is true, my driveshaft had been misaligned for at least 24 years/200k miles by my records, but happened to fail two u-joints in a month? Yeah ok. I don't buy that story and if it turns out they got something basic wrong twice in a row, I'm going to be pretty disappointed to say the least.
 
Welp, didn't take much troubleshooting. The front slip yoke is installed in phase.

I guess the tech was right that someone assembled my driveshaft "wrong," but that someone was Toyota and it was supposed to be like that for some reason. Going to give them a call tomorrow and see if they'll correct their mistake (again).

Thanks for everyone's help.
 
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I can’t see if being out of phase causing a u joint to fail. A loose pinion or tcase bearing would be evident by pushing up and down on the flange, with or without the driveshaft removed. Might be easier to tell with the driveshaft removed though.
 
I can’t see if being out of phase causing a u joint to fail. A loose pinion or tcase bearing would be evident by pushing up and down on the flange, with or without the driveshaft removed. Might be easier to tell with the driveshaft removed though.
Oh yeah, it'll trash a U-joint in a hurry... been there, broke that; in my infallible youth and exuberance stage.

The transfer case output bearings are a radial bearing and have a little (visible and tactile) play in them even when new. There is nothing in the output that draws the shaft tight into a set of tapered roller bearings like on the pinion. What I'm getting at is if you crawl under there and get rammy with the driveshaft looking for play, don't be surprised when you find it at the transferase out-put bearing.
 
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Oh yeah, it'll trash a U-joint in a hurry... been there, broke that; in my infallible youth and exuberance stage.

The transfer case output bearings are a radial bearing and have a little (visible and tactile) play in them even when new. There is nothing in the output that draws the shaft tight into a set of tapered roller bearings like on the pinion. What I'm getting at is if you crawl under there and get rammy with the driveshaft looking for play, don't be surprised when you find it at the transferase out-put bearing.
I thought there’s been reports on this forum that the FSM shows it both ways, and trucks arrived with the shaft both ways, depending on year. It just doesn’t seem likely to me that in 25 miles it’ll come apart, if it truly did come from the factory both ways, depending on the year.
 
I guess I was harkening back to US trucks I drove in my youth. In general, out of phase drive shafts are a bad thing.
 
Welp, didn't take much troubleshooting. The front slip yoke is installed in phase.

I guess the tech was right that someone assembled my driveshaft "wrong," but that someone was Toyota and it was supposed to be like that for some reason. Going to give them a call tomorrow and see if they'll correct their mistake (again).

Thanks for everyone's help.
If I can offer any advice in this scenario, be as non confrontational as possible.

Bring them the facts about the situation and ask them for help to fix the vibration.

When you start the conversation with a shop that "they messed up", it always puts them on the defensive. Even if they are wrong.

The best approach, is just to be a little humble (even though I know you're upset) and present it as... "Hey, this vibration isn't getting any better. I've done some homework and this is what I've found. Do you guys think this could be what the vibration issue is?"

Based on how they respond to that, you'll know where they stand.

Over the last several years, I've held many cars back and test driven them for up to 250 miles myself to avoid situations like this. It's unfortunate.
 
I thought there’s been reports on this forum that the FSM shows it both ways, and trucks arrived with the shaft both ways, depending on year. It just doesn’t seem likely to me that in 25 miles it’ll come apart, if it truly did come from the factory both ways, depending on the year.
When the early trucks came out (91-94) the FSM showed the front DS in phase. In 95 I believe, there was a TSB issued by Toyota to change it to 90°out of phase. All trucks 96+ are out of phase.
 
If I can offer any advice in this scenario, be as non confrontational as possible.

Bring them the facts about the situation and ask them for help to fix the vibration.

When you start the conversation with a shop that "they messed up", it always puts them on the defensive. Even if they are wrong.

The best approach, is just to be a little humble (even though I know you're upset) and present it as... "Hey, this vibration isn't getting any better. I've done some homework and this is what I've found. Do you guys think this could be what the vibration issue is?"

Based on how they respond to that, you'll know where they stand.

Over the last several years, I've held many cars back and test driven them for up to 250 miles myself to avoid situations like this. It's unfortunate.
That's basically what I've done. I really want to maintain a good relationship with these guys because, despite this fiasco, they do good work and have pretty good rates. Unfortunately, the guy that i like to work with that is an encyclopedia of Land Cruiser wasn't there the day the u joint failed because when I talked to him yesterday, he immediately knew about the weird phasing.

So yeah, while this stuff is annoying, I'd rather give them a chance to make it right and for their techs to have a chance to learn something new. Doesn't do any good to get mad for something that wasn't malicious.
 
I actually just learned about that mod when I was reading vibration threads. I was planning to just put it in low and pull the fuse, but with all the stuff on that fuse, I may not be able to do the 70 mph test drive I need.
Driveline vibrations can be difficult to diagnose as the vibrations transmit throughout the frame. The least invasive approach is to remove 1 drive shaft at a time and go for a drive.
There is no issue driving without either drive shaft removed and the CDL locked using the CDL button on the dash or removing the CDL fuse once locked. Folks have driven thousands of miles in this state with no ill effects.
However, the truck will handle differently, so be aware.
 
Driveline vibrations can be difficult to diagnose as the vibrations transmit throughout the frame. The least invasive approach is to remove 1 drive shaft at a time and go for a drive.
There is no issue driving without either drive shaft removed and the CDL locked using the CDL button on the dash or removing the CDL fuse once locked. Folks have driven thousands of miles in this state with no ill effects.
However, the truck will handle differently, so be aware.
Driveline vibrations are def the worst possible thing to diagnose.

They all start with a wheel balance and rotation, it just escalates from there to real work and measurements.
 
Driveline vibrations can be difficult to diagnose as the vibrations transmit throughout the frame. The least invasive approach is to remove 1 drive shaft at a time and go for a drive.
There is no issue driving without either drive shaft removed and the CDL locked using the CDL button on the dash or removing the CDL fuse once locked. Folks have driven thousands of miles in this state with no ill effects.
However, the truck will handle differently, so be aware.
It's not the lack of driveshaft I'm concerned about. From what I read, the CDL is on the gauge fuse, correct? I remember a lot of things not working right when that fuse blew on me.

Doesn't matter anyways. Found the issue, shop is going to take care of it, and I'm installing a CDL switch this weekend.
 

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