KZJ78W Timing Gears Damage (5 Viewers)

[Tredder]

Hi Team,

Just to recap. KZJ78W JDM Prado. 1KZ-TE engine. I live in Japan and that's where I am working on the truck.
The engine was running smoothly until the bellow happened.

After about a 2-hour drive and while waiting at the crosswalk the engine started to stutter and run rough.
Drive it home and inspected. There is a light knock and a whining sound that matches with the rpm. Took it to Toyota and they suspect it's a timing issue. Change the timing belt, bearing, tensioner, water pump. They found the timing was slightly off. Reset the timing and still the same knock and whine. Toyota said it would be at least a month before I could get in for repair.
Drove it home and had a good look over the engine. Sounds like the noise was coming from the timing gear cover. Took all the necessary parts off to access and removed the timing gear cover. I think I found the issue. The crankshaft timing gear, idler gear, injection pump gear all have damage on the gear teeth. Also, the idler gear has been rubbing the cover. There are lots of metal bits at the bottom of the timing case. Photos attached.
I imagine the idler gear bolts have sheared to allow the idler gear to move forward enough to run the cover?
Has anyone seen this? I have found one story about this on mud. Sounds like the same issues I'm having. Idler gear bolts shearing.
The gear teeth may be so damaged that the timing has skipped 1 or more teeth. Not sure what gear yet.
The plan is to order new crankshaft timing gear, idler gear, injection pump gear (i think the bearing too?)
Redo the timing and clean the area.

I have a shop manual and am pretty confident I can change the gears and redo the timing. I hope.
Does anyone have insight or can point me in the right direction on tips or other mudders writeups on this?

Cheers

 

[roscoFJ73]

Thats not going to be cheap but you have avoided a major catastrophe. I would have thought Toyota would have done a better diagnosis first time around.

 

[kzj78dp]

Tredder, did you get your timing gears sorted?

I’ve had the same problem. I think mine started with the balance shaft opposite side of the injector pump. Broke the gear off the oil pump, which cracked the front cover plate, and damaged the crank gear. Replaced the oil pump and crank gear. Disconnected the balance shafts. Now I’m getting a whining noise which changes with rpm. While the idle gear looked to be ok-and so left it in, I wonder if there is some slight damage which is causing the whining noise?? Did you ever pinpoint what made the whining noise on yours? Thanks for any help or pointers you can offer!