So after figuring I had rod knock, even a friend agreed it sounded like rod knock, I pulled my oil pan and replaced all the rod bearings even though they all looked ok, just normal wear. The knock was still there.
I noticed that the sound seemed to come from the bottom of the motor towards the back, so it seemed like rod 5 or 6 was knocking. But after this didn't fix it, I noticed that the noise might have been coming from bellhousing, but was hard to pinpoint. Another friend who used to be a mechanic said that he had seen flex plates crack and that may cause some strange noise. I pulled the little inspection plate off and noticed a loose bolt, but couldn't see any cracks, until I pulled the tranny off yesterday and what do I see?



Replaced with salvage yard $50 plate, BAM noise gone....

 

dam the devil!

 

holy crap!

 

Pretty crazy there. Was only 1 bolt loose?

Put some duct tape on it and shes good to go!

 

Yeah only 1 bolt was loose. So I am guessing that maybe the bolt got loose, and that allowed the crack to start and once it started it got progressively worse. Cause the noise sure got progressively worse. Seems I may have had a few days or weeks before it was ripped in 2...

 

wow...very impressive

 

3rd gen 4runner? 5vz? This has been showing up more and more. Also spark plugs rattle loose and the crank bolt comes loose. Oh and the transmission cooler in the radiator leaks so you get "strawberry milkshake"

 

geez..toyota needs to do a recall or tsb if they already havent. i know its an older truck, but still!

 

Yeah, I agree. The thought of that thing spinning around at 5,000 RPM, just inches below my ass sitting in the driver's seat . . . very scary.

 

because one guy didn't use thread locker and/or torque spec?

 

This isn't a once happening. This is on japanese auto motors mainly on 4runners. I've seen this quite a few times.

 

Did you use FIPG as threadlock? FSM calls for 3 threads of each bolt covered in a threebond 1324 or equiv threadlocker. That black goo could be the reason you lost a bolt

 

A guy I knew, his cousin had the flywheel blow off his 383 and up through the floor of his 57 chevy truck.
He doesn't have a right foot anymore.

 

This was what I found when I opened it up. I have had the truck about 6 years or so, so not sure who did this. I didn't see in the FSM about thread locker, just torque spec. Crap, now i gotta pull it back off?

 

double ouch

 

took the words right out of my mouth


that's insane man!

 

Last I heard, a lot of drag strips require cars to run scatter shields for this very reason.

 

I think they call them Horse collars..

 

Your thinking driveshaft safety loop, I think.

And exactly right on the scatter shield part.

 

I see... good to know