Diff/ Trans Help Please

[Mick Feisty]

Happy Holidays!
I'm looking for some direction from those who know...


Based on the noise in the video and the details below, what are your thoughts?

8 new items by Dustin McQuate

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TRUCK:
1994 Triple Locked from the factory.
~ 130,000 miles
Daily driver of about 50 miles/ week.

HISTORY:
4 years ago had a noise on deceleration and a LC shop replaced the rear drive shaft u joint and I had a knuckle job with wheel bearings, brakes and drive flanges completed.

3 years ago I started to get a low "rumble" in the rear. Seemed to mostly make noise when coasting at certain speeds.
Saw that I had a leak at the rear diff with oil being thrown up on the inside of the rear wheels. I took it to a LC shop and they said my rear diff needed to be replaced as there were a lot of shavings on the plug magnet. They sourced and installed a used unit. The sound was gone.
Few months later the diff started leaking again. Breathers seemed clear so I tackled replacing the rear pinion seal. The leak didnt completely stop but was markedly improved and seemed to leak very little oil based on the level when I would check.
I did not check the center or front levels.

About 6 months ago I rolled through a deep high mountain "puddle" (water barely above freezing) approximately 80 feet long, twice. (video included above)
I didnt realize it at the time that submerging my stock breathers could be a problem, which I likely did IMO.


NOW:
I started getting what I would say was the same low "rumble" as 3 years ago. However, it was much quieter than last time. Again, I only could barely hear it when coasting at specific speeds.
I did a couple of longer/ hard highway drives over mountain passes and would say that I worked the truck.
Few days later I have the noise is the video, a loud "clanking". To begin with, it was mostly when coasting or with light throttle. 20 miles later and the clanking is pretty consistent at most throttle levels. It seems to still be more intense at slow speeds, but maybe that's just because it's easier to hear when going slow.

I dont have much experience with wrenching / autos so did some digging here on MUD and did a little investigating.
The knuckles were a mess compared to the last few times I'd been under the truck (admittedly, not a ton given I live at 10,600' with no garage). They were rebuilt ~4 years ago and have generally been tidy.
I checked the breathers and I'd say that the front was clogged. I pulled both, cleaned them and reinstalled (they're stock).
I checked the oil levels of the front and rear diffs and transfer case and all seemed fine.
I then drained and refilled all 3. No shavings.

The sound seemed to have gone away on a short test drive where I did lots of slow coasting and easy throttle.
But on my next real drive (15 minutes at about 50 mph) the noise came back and was very noticeable in town.

To me it seems like Im having problems in the same "area" or with similar systems.

I'm a novice "mechanic" at best so Im happy to have any feedback, suggestions, etc.

Thanks All!

 

[jfz80]

Sounds like u joint. Doubt you submerged breathers on that ru.

Have you ever greased the rear ujoiunt since it’s replacement 3 years ago? Give them all a couple
Pumps of grease every oil change. Might be too late now but give ‘em a squirt and see if it changes the noise.

It’s not actually hitting the muffler from a compromise exhaust mount is it?

 

[Mick Feisty]

Sounds like u joint. Doubt you submerged breathers on that ru.

Have you ever greased the rear ujoiunt since it’s replacement 3 years ago? Give them all a couple
Pumps of grease every oil change. Might be too late now but give ‘em a squirt and see if it changes the noise.

It’s not actually hitting the muffler from a compromise exhaust mount is it?

I havent greased the rear u joint. =-/
I have a FSM so will look into how to add grease. Im thinking that I may need to add to my knuckles as well.
When you say it may be too late... do you mean if I grease the u joint and the noise doesnt improve it may need to be replaced?

Thanks!

 

[jfz80]

Just mean it may have gone to far to save with lube now. They can get that tingy/pingy noise when the bearings go dry and disintegrate. But if a couple Shots of grease in each zerk quiet it down or change the pitch it at least points to it as the likely culprit. Cheapest part too so hope it works out.

 

[BILT4ME]

I agree with @jfz80 . Sounds like another U-Joint. They need to be greased every 5-6K miles or after a water crossing.

What brand U-Joint was installed? Matsuba are good (Cruiser Outfitters) or you can buy a new DS from Toyota that comes with new Toyota U-Joints. About $400, but it's a quick change. You can sell your used DS with bad U-Joints.

 

[SpenserAK]

Agreed, that particular video sounds like a ujoint to me. My rears gave out last spring, one particularly bad, and I had an almost identical sound - also mainly slower speeds, at slack throttle (coasting), and could hear it "ping" real quick when I pressed the gas and put a load back on the driveline. In my case, one axis on the worse of the two joints had completely lost its bearings. They were cheap parts-store joints from the PO, and I knew that, but was waiting for them to go before I replaced them with good stuff, keeping them greased in the mean time. Luckily that job/part is no big deal. Can't speak to any of your other symptoms or history, though.

With the truck parked on flat ground, you can try to jiggle the shaft at each end, with the load taken off the driveline. Given your sound, and assuming it is in fact a joint, I think it will be pretty apparent. There shouldn't be any play.

 

[Mick Feisty]

Thanks a bunch to you all!
I'll look into greasing and then if that doesnt work will look into replacing the u-joints or DS. Hopefully I can borrow my buddy's garage again cause it's no fun crawling under the truck outside in this weather!

 

[Mick Feisty]

I agree with @jfz80 . Sounds like another U-Joint. They need to be greased every 5-6K miles or after a water crossing.

What brand U-Joint was installed? Matsuba are good (Cruiser Outfitters) or you can buy a new DS from Toyota that comes with new Toyota U-Joints. About $400, but it's a quick change. You can sell your used DS with bad U-Joints.

Unfortunately, I don t know what brand. Classic Cruisers did the work so hopefully it was a decent brand.
And thanks for the suggestions on replacement.

 

[SpenserAK]

If the sound is a ujoint, it's probably too far gone for grease to do much, but obviously isn't going to hurt to add more. When I was keeping mine greased pretty regularly, they just had some play but weren't making noises or any vibrations, really.

 

[landtank]

be sure to check the slip yoke for play. I've seen a few fail.

 

[inkpot]

Agreed, that particular video sounds like a ujoint to me. My rears gave out last spring, one particularly bad, and I had an almost identical sound - also mainly slower speeds, at slack throttle (coasting), and could hear it "ping" real quick when I pressed the gas and put a load back on the driveline. In my case, one axis on the worse of the two joints had completely lost its bearings. They were cheap parts-store joints from the PO, and I knew that, but was waiting for them to go before I replaced them with good stuff, keeping them greased in the mean time. Luckily that job/part is no big deal. Can't speak to any of your other symptoms or history, though.

With the truck parked on flat ground, you can try to jiggle the shaft at each end, with the load taken off the driveline. Given your sound, and assuming it is in fact a joint, I think it will be pretty apparent. There shouldn't be any play.

Easy to grease 1 ujoint at a time and test drive to check for change of sound. No change, then grease the next ujoint. Process of elimination. I would check for play first.

 

[Mick Feisty]

Thanks again all!
We have some serious weather rolling in over the next few days so it will probably be a few days until Im able to get under the truck.
I'll check for play in the DS/ u joints as well as slip yoke and report back. In the meantime I'll get some grease and a gun.

I did a little research and from I can tell it's a lot easier to change the entire DS than the individual u joints.
So, if something needs to be replaced I may just do the entire DS.

Thanks again, really appreciate all of the insight hear on MUD and you taking the time to help a fella out. 👍

 

[b16]

you can also check by locking the center diff and removing the rear DS to see if it has anything to do with the rear DS or not.

 

[BILT4ME]

Thanks again all!
We have some serious weather rolling in over the next few days so it will probably be a few days until Im able to get under the truck.
I'll check for play in the DS/ u joints as well as slip yoke and report back. In the meantime I'll get some grease and a gun.

I did a little research and from I can tell it's a lot easier to change the entire DS than the individual u joints.
So, if something needs to be replaced I may just do the entire DS.

Thanks again, really appreciate all of the insight hear on MUD and you taking the time to help a fella out. 👍

Make sure that when you check the U-joints that you UNLOAD the drive line.

Chock the wheels, set the parking brake, place the truck in NEUTRAL. This does NOT mean have the wheels off the ground, it is only to release the binding in the drive line. Move each end up and down, side to side. They will have some rotational play due to pinion clearances as well as differential clearances. If you can see the pinion itself move up and down, then that is a pinion bearing. It it is just the DS, then it's the U-Joints.

You can tell it's the U-Joints due to the "high pitched pining" noise that's echoing through the DS. It's very crunchy which tells me the needle bearings are already junk due to lack of lubrication.

What is your lift / suspension? This may be affecting the issue.

 

[Mick Feisty]

Make sure that when you check the U-joints that you UNLOAD the drive line.

Chock the wheels, set the parking brake, place the truck in NEUTRAL. This does NOT mean have the wheels off the ground, it is only to release the binding in the drive line. Move each end up and down, side to side. They will have some rotational play due to pinion clearances as well as differential clearances. If you can see the pinion itself move up and down, then that is a pinion bearing. It it is just the DS, then it's the U-Joints.

You can tell it's the U-Joints due to the "high pitched pining" noise that's echoing through the DS. It's very crunchy which tells me the needle bearings are already junk due to lack of lubrication.

What is your lift / suspension? This may be affecting the issue.

Perfect, thanks for the details.

2.5" OME.

 

[BILT4ME]

Perfect, thanks for the details.

2.5" OME.

If the lift was done after the U-joints, it's not uncommon for a new lift to change the driveline angle and cause worn-in U-Joints to fail shortly after the lift installation.

If the U-Joints were changed after the lift, then it was dues to lack of lube.

Also, grease your U-Joints in the same manner as checking them that I listed above. This allows the grease to get where it NEEDS to be instead of squirting out the path of least resistance.

 

[Mick Feisty]

If the lift was done after the U-joints, it's not uncommon for a new lift to change the driveline angle and cause worn-in U-Joints to fail shortly after the lift installation.

If the U-Joints were changed after the lift, then it was dues to lack of lube.

Also, grease your U-Joints in the same manner as checking them that I listed above. This allows the grease to get where it NEEDS to be instead of squirting out the path of least resistance.

Good deal thanks.
The lift is over 7 years old.

 

[Mick Feisty]

Good deal thanks.
The lift is over 7 years old.

So I’m guessing it’s a lube issue

 

[Mick Feisty]

Hoping some of you guys are still following along with the thread....

Its been slow going as life got in the way, but I got under the truck with it in neutral and from what I can tell there was no side-to-side or up-down play in the shaft.

So, I plan to grease the u joints and slip yokes (both front and rear though my issue seems to be in the rear).

Ive read some threads and it sounds straightforward.... fingers crossed the grease gun doesnt get stuck on any of the zerks.

I plan to add the Valvoline Palladium 3% Moly to everything.
The truck will be on the ground and in neutral.

For the u joints, sounds like I just add grease until the old grease oozes out.

But, for the slip yokes there seems to be contradictory info. With the truck on the ground and in neutral can I just add until it oozes out?

Any input/ insight is appreciated!

Thanks guys.