Driveshaft question (1 Viewer)

[COS80]

Rear axle on jackstands, t-case in neutral for greasing, I pulled the rear driveshaft up and down and I can definitely feel it clunk, and from what I can tell, it's in the splines, not the u-joints, because I yanked on the ends while pulling down in the middle, and then I couldn't feel the clunk anymore. I assume this means the whole drive shaft is going to need to be replaced, because the splines are not serviceable. Is that correct? Is there any useful life left in it, given I have no driveline vibrations, or am I already on borrowed time?

 

[manofthewoods]

Rear axle on jackstands, t-case in neutral for greasing, I pulled the rear driveshaft up and down and I can definitely feel it clunk, and from what I can tell, it's in the splines, not the u-joints, because I yanked on the ends while pulling down in the middle, and then I couldn't feel the clunk anymore. I assume this means the whole drive shaft is going to need to be replaced, because the splines are not serviceable. Is that correct? Is there any useful life left in it, given I have no driveline vibrations, or am I already on borrowed time?

Well, we ARE all on borrowed time...
Seriously, have you pumped grease into the splines via the "zerk?" In theory, that should/could solve your problem.
Others no doubt will have more experience to add.
Good luck

 

[COS80]

Both shafts were serviced 2,045mi ago, including painting the splines with moly paste. Greasing the rear again just now didn't change the clunk (though I haven't driven it yet.

 

[77mustard40]

What did the splines look like? I tore up a shaft having too much fun a few years ago and at that time a new one was right at $400 so I went that way vs repairing the one I had.

 

[COS80]

They looked fine the last time. I didn't remove it today.

 

[BILT4ME]

If you're not feeling or hearing any vibes, keep driving it.
How many miles on it?

No, the splines on the yoke are not serviceable other than greasing them. The gaps will remain.

I replaced my rear DS with a new Toyota one because I was having a clunk at acceleration from a stop, but only after I had driven about 50 miles. I was able to notice a very slight wear groove that the shaft was hanging up on because it had worn in the same place for years.
I replaced it because I knew it was still the original shaft, the u-joints could stand replacement, and OCD. The truck had about 350K miles when I replaced it.
Yes, the clunk went away.

Could I have driven more with the old one? Absolutely. I'm a bit over the top on maintenance on my DD. I travel at a moment's notice halfway across the country to job sites and my work and life are in that truck. I rely heavily on it, so I won't risk having a breakdown. If all I was doing is off-road then I probably could have kept running it.
I could probably sell the old one to someone on here for a spare.

Keep it greased and keep a vigilant eye on it to make sure you don't have vibes or clunks, replace it when you have time and can afford it. Replace the hardware when that time comes.

 

[jonheld]

A worn drive shaft slip yoke will often manifest as a "buzz" type of vibration at highway speed when at the sweet spot between acceleration and deceleration (coasting).
With any load on the driveline in either direction, the "buzz" will stop. Greasing the splines will only have a temporary affect.

There should be zero rotational play between the 2 halves of a drive shaft.
That said, I have driven far too long on shafts that exhibit a "buzz". It's not ideal, but for a daily driver, it won't do any damage unless it becomes severe.

 

[COS80]

I assume it's original, with 248kmi on it. I can't say I've heard a buzz at coasting. I forgot to twist it for rotational slop, so I'll do that tonight.

 

[COS80]

It's back on it's wheels and in gear, and there is no rotational movement, or even the spline looseness I saw last night. One of these setups must be wrong, but I don't know which... it would seem to be pointless in neutral, because how would I tell the difference between u-joint slop and the natural play in the t-case/diff, but testing it like this also seems pointless, because it's all under tension.

 

[Broski]

If you’re not getting noise or vibration, run it !

 

[BILT4ME]

It's back on it's wheels and in gear, and there is no rotational movement, or even the spline looseness I saw last night. One of these setups must be wrong, but I don't know which... it would seem to be pointless in neutral, because how would I tell the difference between u-joint slop and the natural play in the t-case/diff, but testing it like this also seems pointless, because it's all under tension.

In neutral, wheels chocked. You hold both end or parts of the same shaft.

 

[COS80]

If you’re not getting noise or vibration, run it !

Well i am getting one noise... the intermittent squeak i just can't find. I'm planning to regear soon, and if the squeak is a bearing in the t-case or a diff, that'll be the deciding factor in which gears I change.

 

[COS80]

In neutral, wheels chocked. You hold both end or parts of the same shaft.

Ok, that made a difference. Splines are clearly worn, but the u-joints seem sound. As Broski said, I'm just going to run it until it becomes a problem.

Thanks!

 

[Kernal]

"Both shafts were serviced 2,045mi ago, including painting the splines with moly paste"

(Edit: wrote this before you stated above that the splines are loose)

You mentioned that the shaft (s) looked OK when you serviced them, so no signs of accelerated wear or looseness when you put the shaft back together?
Did the U-joints move freely?
Did you drop both ends of the driveshaft(s)?

Agree what others have said, keep the slip-yolks and U-joints well lubricated (IME every ~5000 miles, at least, if the U-joints are originals) and drive it until you hear/feel something.

OR, buy new front and rear OEM driveshafts ("Propeller Assemblies") now while they're still available from Toyota and install them next time things are all apart.

 

[COS80]

You mentioned that the shaft (s) looked OK when you serviced them, so no signs of accelerated wear or looseness when you put the shaft back together?
Did the U-joints move freely?
Did you drop both ends of the driveshaft(s)?

I thought they looked ok, but I readily admit that I don't really know what I'm looking at. Odds are they were worn then, and I inspected them wrong. U-joints moved freely, and I had the shaft removed entirely.

On a related note, I just discovered that my rear sway bar link bushings are completely shot.

 

[landtank]

I have rear slip yoke available on my sight.

 

[COS80]

Do dry splines squeak? I've driven it twice, now, under the conditions that generate the squeak, but no squeak. I wonder if I undergreased it the last time,.thinking the moly paste had me covered better than it did. It got three pumps, last time, and six this time.

Could just be another fluke, too....

 

[LC4LIFE]

If you are trying to rule out the squeak coming from the DS, just pull it and drive it and see if it goes away.

 

[COS80]

If it starts up again, I'll try that. Fingers crossed that it is gone.

 

[Kernal]

IME brushing Moly lubricant (LB8012) on the slip yolk splines followed by fully greasing the splines would not cause a squeak, the purpose of the Moly paste is to prevent metal-to-metal contact but it should not be used by itself ie: you must also grease the splines. The purpose of adding the Moly paste IMO/IME is to "boost" the long term protection of the splines. If greased correctly there shouldn't be any noise coming from the splines assuming they are in good shape.

To ensure the splines are fully greased (and not overgreased) you can first pump grease into the slip yolk until you see the shaft extend, then remove the zerk fitting (?7mm socket), watch for air or grease to come out the zerk hole, replace the zerk fitting.

Do not use the (LB8012 65% Moly) Moly paste in the U-joints.

As mentioned above, if you think the noise is coming from a driveshaft one method to help determine the source is to engage the Emergency brakes, remove the shaft in question, lock the CDL, then drive the vehicle to see if the noise is gone. To lock the CDL (if you haven't done it before) first start the vehicle, shift the transfer case to LO (ABS and Diff Lock lights should come on), shut off the vehicle, pull the DIFF Lock fuse, shift the transfer case back to HI. The ABS and Diff Lock warning lights should remain lit in the instrument cluster (with the key ON) if the CDL is locked, then it's safe to drive with a driveshaft removed.