Loose Crank Bolt Issues to Know About?

So I have a 95 4wd 5spd with the 2.7 3rz. A few months me and my dad replaced the oil pump, but we did not realize until later that we had forgotten to properly torque the harmonic balancer back on. Apparently we had slid the pulley on to the oil pump, but did not slid it on to the key. When we tightened it, it was just pushing against the key instead of on it.
I blew a belt one day, so we fixed it and didn’t think much of it. Well, a few days later I was driving to school and lost oil pressure. I left it at school (got a ride from a friend) and my dad came down that afternoon to look at it(at this point we were not aware of the bolt not being torqued right). My dad crawls under it, sees that the harmonic balancer is tilted, so he tightens the bolt and tries driving it home. Well he didn’t get far before the oil light came on again and when he pulled over, he realized that none of the belts or pulleys were spinning(the engine was running though)(the pulleys were spinning fine when I drove it), even though the balancer was on pretty tight. He towed it home and when we tore it apart, we saw that the inside of the balancer pulley was filled with metal shards, the oil pump front seal was leaking due to the angle of the pulley, but the crankshaft was good except for a few burrs. The key was also in place, as we thought that the key may have been sheered. We smoothed it out, got a new pulley and put the old oil pump cover on(the new one broke when we took it off) with the new oil pump gears(it fit just fine), along with a new seal.
It started up and ran fine until it got up to temperature after being run for a little bit. When it was hot and the rpm’s dipped under 1000, the oil would light come on, but go away when it got over 1000.
We figured it could be:
-The viscosity of the oil(we put synthetic in it a few months ago since we put the old oil pump cover on, it could be worn a little bit causing the thin oil to slip by when it’s hot
-The oil filter picked up metal when my dad was trying to drive the truck home (that’s when most the damage was done to the pulley)
Yesterday we changed the oil back to 10w-30(not synthetic) and put a new filter in. It runs completely fine and the light no longer comes on under 1000 when it’s hot.
Sorry for this being long, I just want to know if there could be anything else damaged by the pulley coming loose (I don’t want to be driving one day and have something major break on me). Everything seems fine and it runs like it used to, I am just hoping that there is no internal damage or something that will pop up later on. I appreciate any feedback

 

May have scored some main or rod bearings from lack of oil.

 

Are there any signs that would show if they have been damaged?

 

Low oil pressure at idle.

 

My Harmonic balancer wobbled so bad in the end.....it cracked the inside of the timing cover....
right where the oil pump seats and spins......

That HB sticks back into the time cover and pump gear to seat againt engine front....

It was a very fine crack ....simi circle about 1/4 way around oil pump inner seat against timing cover.....

That crack will leak intermittently......synthetic should cause it to leak the most....
when hot....it might gush....

And for a bonus on mine.....someone in past seated a new HB wrong and damaged the crank key.....after spinning out several HB's that key seat got wollowed out and destroyed the crankshaft.....

 

And we thought the same thing ......the bolt was torqued down correctly....
its just when that HB goes out.....it backs that bolt out and can cause a lot of damage...

Another weak point on these......a lot of systems driving off that pulley......

Most everybody is floored when they see that wobble for first time......rubber mounted whaaaaaatttttt ???????

 

when your in there.....u always

do,,,,front engine seal...
that inter oil pump seal againt the HB shaft...
new oil pump gear......
new oil pump cookie seal for pump cover...
new allen screws for cover....LCE......
And a brand spankin new HB center bolt.....they're non reusable.....supposedly.....


And then you very carefully seat the new HB.....it has new sharp edges on it ....
....and may catch crooked.....damaging key and the new HB at same time......
You'll know its wrong...because now the belts dont line up.....little off now....

if you get that step wrong....it will only last few hundred miles before it spins out again...........and get that 'whole dash warning lites up'........and most likely damaged crank key little more.....
Most think they didnt tighten that bolt down enough.....but that's not it.... its because its spinning free after the HB starts messing up.....grinding.....

 

So you could be losing oil pressure due to HB starting to spin on crank key...
it drives the pump gear......

or maybe crack in oil pump area......and even both.....



A lot important stuff right there.....if they is any problem....best to shut down immediately...and tow.....

So important .....think I'm gonna to add to the LBJ list.....gonna swap my doorman one out now every 100K.....
that wobble can devastate a 3rz / 2rz.....

And always file edge off the key slot on the new HB....at least a tiny bit right at the lip....


As you can see ....it didnt end well for Buttercup 1.0 .....

 

And this aint nothin.....

now that you've over heated.....you'll have to watch your coolant...

2rz/3rz heads crack like crazy when over heated......
right between the two valves.....intermitant....will be good days and bad days on the coolant loss.....

5VZs seem little tougher.....


Sorry....they dont like me very much at work either........
.....I'm always seem to be delivering bad news......

 

Well good news....because of popularity of these and the 4-runners....
you'll find no shortage of anything you want for these......

Just need to do your homework........bunch of these guys here have the magic touch for getting hard to get parts.....

Or tech specs.....and fsm clips for any year....any model.....

 

The crank bolt is something like 187ft/lbs. Gotta use one of those tools that bolt into the HB, I put a breaker bar on it and rotated the engine until the bar hit the frame. Took the torque wrench and put both feet on the wheel and pulled. Took me a minute to get it that tight... its really tight.

It'll back out quick if its not torqued and you're in for a mess then. Like Silver Taco mentioned... new bolt, they're not horrible like $15

 

Get your hands on a mechanical oil gauge and get an oil pressure reading when the engine is cold and when the engine is at operating temperature. You want to make sure that you have adequate oil pressure. There might be some damage where the oil pump meets the engine block and you might have scored it a bit. The only way to tell is to remove the oil pump and take a look.

 

The oil pump sits between its own cover and the timing cover....

that timing cover is fairly thin.....

could not even tell mine was cracked.......until I put a flood lite behind it....
tiny crack about 20% around HB shaft opening.......

Had to do the emergency fedex thing after that........


Fortunately/unfortunately I had the timing cover off at the time......I dont think I would have seen it or caught while still on the engine.......

 

Did you order the Aisin timing cover from Rockauto? Was pleasantly surprised when my Aisin one showed up with "Toyota" poorly scratched off it. 1/3 of the price!