Drivetrain clunk saga: Grease, new shaft, empty transfer case. Still there...

[Cog]

My baby, with 251,000 miles, is perfect in every way. Well, except the seats...they are rough.
But mechanically she's an angel.

Until a month ago, I noted the dreaded clunk somewhere in the drivetrain while under load (acceleration). At first, it was just a few clunks and the feeling that the push to the wheels just stopped for a second.

Google-fu said grease!! Greased all zercs. Did not fix it. Maybe lessened the noise for a bit but then it came back.

Google-fu, well, Yandex at this point, said Your Driveshaft Was Recalled. So off to eBay to buy a Lexus GX470 used shaft. As per the part number. Quick bolt right up, greased it, and off I went.

Clunk, clunk, clunk.

Still there. If anything, maybe a little worse.

So back up on the jack stands. Decided it had to be either a Diff, or the transfer case...oh that reminds me. After replacing the shaft, the 4LO indicator would light up intermittently during the Clunking. Not on, just flicker like a light bulb about to go out...so that's odd.

Pulled the fill bolt out of the transfer case, stuck in a finger....EMPTY.
Well that sucks. Grabbed some Mobil-1 synthetic 75w-90 and some Lucas oil leak stop at Autozone (my Napa was closed of course). Dropped the drain plug and about a shot glass of black oil came out.
Filled her back up, quick test drive...CLUNK...but lighter and less frequent.

Google-fu said that actuator seals leaking is a thing in this Generation. Who knew?
So now I'm wondering this:

Could the actuator rod, or gear engagement, be partially engaged and causing the Clunk?
When engaging 4LO on the dash, NOTHING happens. No light, no 4LO via the throttle indicating it engaged.

I'm at a loss now. I welcome the great wisdom that is this site. Y'all have helped me a TON. Thanks.

 

[Cog]

Reminder..Wild Speculation Welcome

So now I'm wondering this:

Could the actuator rod, or gear engagement, be partially engaged and causing the Clunk?
When engaging 4LO on the dash, NOTHING happens. No light, no 4LO via the throttle indicating it engaged.

I'm at a loss now. I welcome the great wisdom that is this site. Y'all have helped me a TON. Thanks.

Please reply if you have some thoughts on this. I don't mind tearing into the actuator but I'd prefer to know if that's likely to fix it. Thanks!

 

[Drcoffee]

Bummer. It would seem logical that after driving for who knows how long without lube in the transfer case, the gears might be worn beyond repair. im guessing you need a new one . It would certainly cause clunking whilst driving. Prob about ready to grenade. The dreaded cluck in the back from the drive shaft was only during braking. Not what you described.

 

[Cog]

Bummer. It would seem logical that after driving for who knows how long without lube in the transfer case, the gears might be worn beyond repair. im guessing you need a new one . It would certainly cause clunking whilst driving. Prob about ready to grenade. The dreaded cluck in the back from the drive shaft was only during braking. Not what you described.

Thanks, Dr. Any experience with rebuilding (possible?) vs. buying a used one?
I might try to snake a horoscope into the housing via the fill bolt and see if I can see any damage.

Thanks for weighing in. Every bit of insight helps me narrow down what to do next.

 

[Cog]

EXPERIMENT-
Watching this incredible video on Toyota transfer cases https://www.youtube.com/watch?v=ESm0PPBkAQQ

I'm wondering if the random "slip and clunk" under power is chipped tooth or chain link.
What do you think about pulling the front driveshaft off the truck and test driving to see if the problem is in the chain or front gear transfer?
Any risk of other damage to doing that?

Likewise, do the same to the rear drive shaft and carefully test drive (I'm sure that's a lot of torque to the front axle that could do some damage if over done)?

 

[grumpy02]

Not much of a T/C guru here but removing the driveshafts independently should do no harm & will eliminate them from the equation. If the clunk is in the T/C it may not go away with the D/S removed. Certainly worth trying.

 

[Cog]

Thanks Grumpy. I'm dumb enough to try it. I'll report back.

 

[Runnin on E]

Just so I have the situation correct, your 4hi/lo actuator is stuck/toast and also you ran the transfer case without oil? If you use carpart.com you might be able to find a used transfer case in your area. I was looking for an FJ case just last night for a conversion to manual transfer shifting (because of the actuator failures) Search here for actuator issues and you will see why. I would not go rebuild just for time, cost and special tools but the procedure is in the factory manual which you can also find here in a search. I saw a used transfer for an FJ for $800.

 

[Hungryhawk]

You may have more than one issue with overlapping symptoms.

You replaced the drive shaft with used?
Try a test in driveway: foot on brake shift into "D"
Wait a minute or so then shift into reverse -keeping your foot on brake. Wait a minute or so then shift into "D".
Do you get a clunk? Can you repeat and always get a clunk?

This test is a classic U-joint test. Worn U-joints often conceal the wear till a load is applied.

Sorry about your TC. I see that can happen because gear oil would just drip as you drove. Did you see a oil spot where you usually park?

 

[Cog]

Runnin' on E-
4LO does not work. But part of the odd symptom was when the drivetrain clunk was more pronounced, the 4LO dash light would flicker. Once I think it stayed on but of course I was driving as normal.
Yes, for some time the TC was oil-less. Leaking through the actuator as noted.


HungryHawk-
Since we only have a gravel driveway, and I park in different spots, I never noticed the leak. And yes, I replaced the old rear driveshaft with a Lexus model of the same part number (revised part number). I'll try the universal joint test. Thanks!

 

[Runnin on E]

There are plenty of threads on the actuator failure so I won't go into that here again. It seems to me that you will at least be looking to get the actuator unstuck. You know for sure that is a problem, so I would get that solved first. As I said, you might want to see if you can find a transfer case with an actuator already on it. Unless you are super handy and have a good selection of tools, taking that actuator apart/off can be a pain. Search here and read up on that.

 

[Cog]

Great point, solve for the 4LO not engaging first. Copy that. I'll report back once I can get back underneath her.

 

[Runnin on E]

I just thought of something, since you had at one point a blinking/intermittent 4lo light you could start with the connectors for the actuator to see if they are in good condition and the wires going to and from the connectors. If there is a bad connection or broken or bad wires that might be why the actuator isn't working.

 

[Runnin on E]

Also, there is a feature built into the 4WD system that will let you know if the "mode" you selected has not completed or is not engaged. This is a blinking light. So if the wiring/connectors are good then the next step would be to look at a frozen or seized actuator. So when you select 4lo and the transition to 4lo doesn't get completed you get a blinking light OR a broken wire is shorting or grounding out. Either one is possible right now until you check things out further.

 

[rdruss]

If this is an AWD 4Runner it's hard to believe that the T-case is not scrap. Bushings/bearings shot, chain wasted, etc. If the u-joints are good, I would be looking for a replacement case. Forget messing with the actuator, that's a nightmare in itself.

 

[Runnin on E]

If this is an AWD 4Runner it's hard to believe that the T-case is not scrap. Bushings/bearings shot, chain wasted, etc. If the u-joints are good, I would be looking for a replacement case. Forget messing with the actuator, that's a nightmare in itself.

I agree but not all replacement transfer cases will come with an actuator. It seems like it is going to be toast but a few minutes underneath could be worth it. I have been looking into a spare new actuator myself, they can be had for around $400-500. And as stated above a used transfer is $800-1200. And those are do it yourself prices.

 

[Cog]

Agree that this V8 TC should be toast. I'd estimate it was run with low or no oil in the TC for hundreds of miles. I really don't know.
But Toyota build quality continues to amaze me.
I'm confident the TC is not long for this world but it keeps running...


QUICK UPDATE

Performed the joint test. No noise, no feeling of slop or slack.

Drove to Napa this morning. Periodic clunk under load, as usual.
Got home, warm truck, attempted to engage 4LO. Nothing. No light, no sound.

Rolled the truck on ramps and while running unplugged the TC top plug (see pic). Looked clean and dry. Plugged it back in.

Plugged in the OBD reader. No codes.
Wondered about the 20 amp fuse for 4WD in the cabin. Pulled it, again while running. It looked fine. Plugged it back in and got VSC On and Off lights, 4LO light and the Diff Lock light on the dash. Attempted to cycle 4LO. Nothing happened.

Ran the OBD scan, see video. I've run the Zero Point calibration before so I can reset that.

Once I clear the codes, I'll attempt the actuator tap while cycling to see if I can get the servo to engage.

Clunk and dash lights https://vimeo.com/1051993995?share=copy#t=0
OBD code ODB codes

 

[Runnin on E]

OK if you think the wiring to the actuator is good then you are on to the next kick in the shins...the actuator OR replace the whole contraption (transfer and act). Good luck on your project.

 

[Drcoffee]

What rdruss said. You cant run a gear box without lube without grinding it out of spec. Find a good used one.

 

[Cog]

Last SAGA

After unplugging the actuator while the truck was running, VSC On and Off lights are solid, 4LO is solid, and the Diff Lock indicator solid.

ODB said Zero Point Calibration needed and C1340, Open Circuit on Center Differential Lock.

So I ran the Zero Point multiple times. Can't get it to stick. BUT now the ABS light is blinking along with all of the lights above.

Oddly it drives fine (with the clunk under load, of course) so it's not in 4LO.

I'm going to hunt for a used TC now. Gremlins are maddening.
Thanks for everyone's input.