who had this problem: chain of transfer case broken

[Jan777]

My V8 Limited started to make a strange metallic clicking in the front when accelerating. Found a mechanic specialized on 3rd gen. T4Rs. He maintains dozens of 3rd gen for a large energy company in this area.

He immediately recognized that the chain of the transfer case was the problem. The chain skips on the gearwheel, which causes the metallic sound. Removing the transfer case means that the vehicle would run with 2 wheel drive, with power only on the rear wheels. We will check if the transfer cases for the 3rd gen fits also on my 4th gen. On the outside, the size and construction looks like the same.

I asked the mechanic if this was a known problem, and he just pointed to a good dozen of transfer cases he had lying around in his workshop, saying that it is a typical T4R problem.

Its the first time I hear about that. Wanted to check with the forum if anyone else had the same problem?

What did you do? Did you replace the entire transfer case? Is there a way to fix the chain and the gearwheels? Any good source for 2nd hand transfer cases?

 

[dkyleb]

My V8 Limited started to make a strange metallic clicking in the front when accelerating. Found a mechanic specialized on 3rd gen. T4Rs. He maintains dozens of 3rd gen for a large energy company in this area.

He immediately recognized that the chain of the transfer case was the problem. The chain skips on the gearwheel, which causes the metallic sound. Removing the transfer case means that the vehicle would run with 2 wheel drive, with power only on the rear wheels. We will check if the transfer cases for the 3rd gen fits also on my 4th gen. On the outside, the size and construction looks like the same.

I asked the mechanic if this was a known problem, and he just pointed to a good dozen of transfer cases he had lying around in his workshop, saying that it is a typical T4R problem.

Its the first time I hear about that. Wanted to check with the forum if anyone else had the same problem?

What did you do? Did you replace the entire transfer case? Is there a way to fix the chain and the gearwheels? Any good source for 2nd hand transfer cases?

Your mechanic sounds like an idiot.

Removing your transfer case means the vehicle will not drive at all. Have you even looked underneath your vehicle?

The transfer case in our trucks is extremely durable. If your chain had any breakage, it would probably fail catastrophically.

It's most likely a CV clicking.

 

[Inv4drZm]

From what I know from the forums, our transfer cases aren't prone to failure. Other things usually fail before the transfer case such as rear diffs or CVs. Nothing I would classify as "typical" like your mechanic did. Weird.

 

[TowMeOut]

Go find one of the internal drawings of our 4th gen t-case. The hypoid gears look like some kind of demented meat grinder. That chain coming loose or even out of alignment would likely grenade the case or at least cause way more than a "click".

I just did an actuator repair on mine and I can tell you for sure there's no running it in "2wd" without the case. Removing the case means there's nothing to connect your rear driveshaft to (maybe you can transplant the tail shaft from a 2wd setup??).

I'd guess this "mechanic" has cost that energy company many tens of thousands of dollars of unnecessary repairs over the years. Any bets that pile of t-cases ends up on Ebay some day??

 

[dkyleb]

 

[Jan777]

thanks for the feedback!

Yep, thats the chain!

Today after work i will check with the workshop. I also have my doubts about the chain of transfer the case being the culprit! I actually purchased CV axles and new rubber boots and brought them with me to the mechanic. I would have fixed it myself but just don't have the time!

The mechanic was sure that the chain of the transfer case would be the problem.

Will let you guys know what comes out of this. Really need my 4Runner back & running!

 

[Jan777]

Ok mystery solved: the transfer case had nearly no oil left in it! Had it last serviced at Toy dealership and explicitly asked to check oil on ll transmission parts! That's less then 4k mikes ago! Damn idiots!

The mechanic now changed the chain and the bearings. Lucky that I had not more severe damage! Never trust these Toy dealers in some underdeveloped country!

Sent from my SM-G800H using Tapatalk

 

[Jan777]

it WAS the transfer case

The transfer case was nearly empty on oil, now we fixed the chain (changed it) and are getting new bearings.

We also did the outer boots on both sides. The joints on the CV axles are O.K.

I am stationed in Kosovo (Europe) and made the mistake to trust the local Toyota rep. It's an original rep office but the standard of their service is miserable! I had asked them explicitly to check all transmission fluids! That was less than 4k miles ago!



Pics attached:

 

[TowMeOut]

Actuator??

Ok, I have to ask.....where is your t-case actuator?? I ended up in the same boat (truck stuck in 4-low, had a 10 hour drive home) when I ended up dismantling the actuator so I could shift into high range manually. It took me a month of Sundays reading this forum and a $500 actuator off Amazon to get my truck back on the road.

Maybe it's just the photos but all that spilled fluid on the outside of the t-case looks red. Any idea what kind of fluid they put in the t-case?? It should be 75-90W gear oil, not ATF (which is normally red). Maybe the wrong fluid and very little of it are both contributors to the problem. Glad to hear you're getting your rig back together. At least you're not driving a Ford/Chevy/Dodge. I spent 4 years in Germany and the folks that brought over US spec/brand vehicles were totally screwed when they needed service.

 

[BlackWorksInc]

I haven't heard of a chain failing on a Toyota transfer case made in the last 20yrs, at least not that I know of. Maybe if you're really abusing the **** out of the vehicle, but usually you'll blow a diff or a CV axle before that happens.

 

[Brian3676]

Good luck re timing the actuator. Should not have taken that off from the outside. In fact, I did not even know it was possible.

 

[Bumbo]

Not to defend the mechanic in any way but if you asked me to check your transmission fluid I wouldn't go tinkering with your t-case...

Was this just a miscommunication or did they know what you wanted? Where you charged you for drive-line maintenance items, and they just not do it?

If your t-case was dry maybe you have a leak somewhere?

Sucks you can't find a better shop, but happy to see you making progress.

Also interested in more details about the current state of the t-case and actuator.

 

[Jan777]

If your t-case was dry maybe you have a leak somewhere?

Yep. the sealing rings on the transfer case/actuator were gone, which caused the loss of oil. We got that replaced also.

The previous pics were taken during the works, with the actuator off. It's now on and works fine.

To those who have never seen a chain go bad: yes it happens! Particularly when you don't have any oil in the case! The chain got stretched and started skipping the teeth on the gear. A fraction of a millimeter is enough to get the chain out of sync!

Why? Well I ride the 4Runner in Europe on long distance travel (600m+ each way) and on constant high speed (80-110 mph), so a dry transfer case on these travels creates a problem!

One thing I learned: NEVER diagnose on first view. As you can see on the pics I ordered two CV axles, being sure the problem were the axles! I just saw the rubber broken on one of the boots, but did not lift the car to check all other parts. Paid ridiculous costs for shipping two axles from the U.S. to Europe and waited three weeks - just to find out that I don't need them! Well, at least I got some spares now. The good news: 3rd gen chains fit on 4th gen! So I got it all fixed (replaced the chain with a used one), sealed and filled with fresh oil, for all together only 500 euro (that's about 580 USD). THAT's again the advantage of working/living in an underdeveloped country, prices of labor are low!

Pics: the chain of the transfer case, the sealing rings we changed, the outer boots of the CV axle

 

[Bumbo]

That chain looks like something Chuck Norris would wear around his neck.

Or maybe the chain is wearing Chuck Norris.

 

[Jan777]

sorry for bothering with Jeeps

but it seems that a stretched chain was not exclusively my problem. Different brands, same problem, particularly when running on a dry TC:

transfer case chain stretch - Tech Talk - Midsouth Jeep Club
Transfer Case fix...question on chain slack w/ pics - JeepForum.com
Transfer Case Chain - Ask the GM Technician - GM-Trucks.com
https://www.jeepstrokers.com/forum/viewtopic.php?t=2246
Symptoms Of Transfer Case Chain Stretch? - R3VLimited Forums
https://ck5.com/forums/threads/how-to-identify-a-worn-transfer-case-chain.92491/
https://www.youtube.com/watch?v=vsNhggcwd3c

 

[4Runner010]

I blew my rear diff and I think I hurt my transfer case in the process. Truck will move only in low and reverse but drive, 3, 2 will not move my truck they seem as if they are neutral. Is this tranny or transfer case ?

 

[GLP]

Ok wait a minute. The actuator is supposed to be removed and reinstalled when the TC is apart. In the photo the actuator is removed while the TC is still on the tranny. I know some have attempted to remove the actuator to replace those seals with the TC still on the tranny to get around not having to remove the TC (not recommended by Toyota!), but if you had to take the TC apart anyway to replace the chain then why not do the actuator repair the proper way.

If the mechanic got it back together ok and the actuator still works fine (shifts 4Hi/Lo and CDL lock/unlock) then consider yourself lucky. The plastic gears in the actuator that mesh with the teeth on the metal shift rods in the photo probably got slightly damaged when it was removed and reinstalled, but obviously not enough to mess up the functionality of it.

 

[Jan777]

Ok wait a minute. The actuator is supposed to be removed and reinstalled when the TC is apart. In the photo the actuator is removed while the TC is still on the tranny. I know some have attempted to remove the actuator to replace those seals with the TC still on the tranny to get around not having to remove the TC (not recommended by Toyota!), but if you had to take the TC apart anyway to replace the chain then why not do the actuator repair the proper way.

If the mechanic got it back together ok and the actuator still works fine (shifts 4Hi/Lo and CDL lock/unlock) then consider yourself lucky. The plastic gears in the actuator that mesh with the teeth on the metal shift rods in the photo probably got slightly damaged when it was removed and reinstalled, but obviously not enough to mess up the functionality of it.

The TC was taken off, the chain replaced, the actuator removed, TC without actuator and new chain put back to check parts fit well, than TC was taken off again, actuator installed with new seals, all together re-assembled. No worries, the shifter works fine. Just drove to Greece and back, 500 miles.

 

[GLP]

The TC was taken off, the chain replaced, the actuator removed, TC without actuator and new chain put back to check parts fit well, than TC was taken off again, actuator installed with new seals, all together re-assembled. No worries, the shifter works fine. Just drove to Greece and back, 500 miles.

OK thanks for clarifying. Sounds like it was all done properly. Seeing the TC on there without an actuator didn't look right.