Broken crankshaft key leads to tear down and timing service

I mean it’s already fucked. So if a jury rig fix gets it to last another 100k to prolong invasive R&R that’s a win.

Just googled broken crank key repair to see what people do, with the crank in or out.
Apparently one guy used adhesive like so:



Consider this. Many vehicles nowadays aren’t even spotwelding the body together any more. They use high strength adhesive.

replace crank would probably cost more than throwing in a used motor.

places do weld repair. But that is on expensive race car motors where it is worth it and the engine is taken out and apart on a bench for welding and precise machining.

 

there may be other ways. For example woodruff key.

groove cut into the shaft
Groove cut into the pulley
Piece of metal matching them


what would they do in Africa or India

 

I’m not familiar with this method I’ll have to look into it. Thank you everyone so far for all the help. Yk you’re fucked when this many people respond this quick on the forum

 

what if this forces you to swap in a:
-GM V8
-Toyota/Lexus V8
-diesel

beater old P71 for around a grand to get around in the meantime could be an option

that front timing cover looks leaky and in need of a reseal anyway at that miles

consider this. Any other car front timing cover would already be leaking by 100k.
I guess this is the one single thing Audi/VW may have gotten right on the 2.0T.


full surface triangular key system on a replaceable sprocket

 

At least you caught it before it completely failed. Not sure what happens when the key on a crankshaft breaks off and the crankshaft pulley no longer spins. At a minimum the water pump & cooling fan stop and coolant temperature starts to skyrocket.

I would guess it's the kind of thing you can hear immediately and would then pull over within 5-10 seconds to investigate. If you were just driving along & didn't hear it let go or ignored the change in engine sound (maybe loud music playing or something,) you would cook the engine in a very short period of time from zero coolant flow.

But anyway, none of that happened because you caught it before the pulley and/or crankshaft keyway broke entirely.

 

Idk man best outcome for me right now is spending the least amount of money I can. I don’t really understand how the woodruff key works.

 

Maybe drill in from the front and tap a steel pin in

 

A used engine would be better than just fixing the crank, just the crank on one with 230k on seems like waiting for other problems. If funds are short - just get a new pully and put it on, call it good enough.

 

I’m still wondering if tightening down the crankshaft bolt tight enough with thread lock on it could be good enough? Does the crankshaft spin in a direction that would unscrew the bolt over time?

 

This is actually possibly not too bad an idea if your budget is tight or you're not trying to keep the truck forever. Being sure to use threadlocker Red, whatever the speciality ultra-high temperature stuff is. Idk, it's possible that might hold for the long term?

 

yes. If there’s a second intact key that would let the pulley sit on right stationary (engine off). Bolt tight
Hole of the right size drilled
A pin would be easy to find
Big enough size chosen
And the single drill hole would match the crank and pulley

question is how to drill perfectly straight and how much room there is

Another option. Slap on a new pulley. And weld it to the crank from the outside if possible before putting the bolt. Might have to grind it flush. But that would make taking it off again in another 200k+ a shitshow. Which may not matter. Or gluing the new damper on.
A weld bead run around the whole diameter gap in a circle might work.

or loctite supposedly has an adhesive that requires an extreme amount of heat to loosen again in the future. ie Torch, that 210deg of motor running shouldn’t mess with. Probably normally used on turbos that can get up to 1000deg.

 

That would just be a risk of doing less instead of more

because the pulley is going to be up against
-torque and rotation of the motor spinning during starting and running
-resistance fighting against having to spin the accessories
-constantly exposed to heat and cold, expanding and contracting
-natural vibration of the motor running


Every now and then there’s used cheap 1GR-FEs for sale on whatever classifieds with owner claiming it to have some other issue, that could be a cheap donor to pull parts from
But that’s still:
-invasive work
-full status of donor motor not 100% known

 

side note
Is anyone else getting paranoid now about ordering a new damper to replace theirs and deal with the PITA of doing that
Maybe it’s not too involved.
-remove fan shroud
-remove fan
-remove serp belt
-replace crank bolt with new during job

RockAuto is cheaper than $200 dealer
But these pics and brand names don’t exactly look quality or OEM supplier brand…


Never heard of ATP (doesn’t even have pic) or Pioneer
Dorman is bad reputation
I have SKP spindles
Dayco might be Autozone type shit and the pic of it shows it not looking how it’s supposed to look


FWIW FluidAmpr told me they have a non Tacoma pulley that is similar enough it might be able to be made to fit
Which if so would be better than OE

PN 571101
But based on pics 1GR has 6 ribs
571101 appears to have 5.

would be awesome if another model ATI SuperDamper or FluidAmpr fits
The 2JZ one appears to also have a keyway slot and be 6 ribs.
Not sure if the diameters and offset spacing dimensions are the same. But they should list all that info online. And stock damper can have measurements taken.

Theres other shit I don’t know about
Like this
ATI drill kit
ATI keyway spacers
Both of which could also be made by a machine shop given specs

 

Yes, the hard part is if it's possible to get in there & drill the hole, and drill it straight. Probably not.

If you go this route I would strongly recommend using an OEM/genuine Toyota replacement pulley. If you weld it on you don't want to have to try it get it off again any time soon.

How about this: carefully file some very gentle linear grooves all around the crankshaft circumference, like 60 or 80 of them, sort of like splines, but just little shallow roughening grooves. Then file similar grooves on the inside of the brand-new pulley. Then use the special high-temperature (search for it, don't just use ordinary Locktite Red) thread locker. The grooves on both surfaces would give surface area for the thread locker to work against and lock into.

 

I was looking at a diagram from a past thread and saw this. Are the keys removable from the crankshaft? Or are they one solid piece with shaft?

 

you better hope that’s the case and that the pic above is from a 1GR. Because if so that would be good news.
And exactly how some other engines are made.

why? Because it would mean what is damaged is a replaceable sprocket and not the crank. But a sprocket that sits on the crank.
Just more involved to replace.
-timing cover remove
-timing chains remove

not impossible if you follow the repair manual.

supposedly it is its own piece sprocket.

https://www.purefjcruiser.com/docs/2007 Toyota FJ Cruiser Repair Manual/1GR-FE Engine Mechanical/Engine/0060013.pdf

that would give you the opportunity to reseal the timing cover which looks like it needs anyway

potential cam gears upgrade
Verifying the engine is in time and retiming it
Potentially replacing timing chain guides if they’re plastic and old



don’t quote me on the PN
Rule of thumb always verify PN’s, supercesions up to date, matching VIN within Toyota parts database

but IF this is the part
Well…$23 OEM…

 

Nice find. Verify 100% certain that it's from a 1GR-FE & proceed w/ further planning from there.

It'd sure be nice if that's replaceable, one of those things where the engineers thought ahead to "what if the crank pulley gets jammed somehow, wouldn't it be nice to be able to replace the key if it gets damaged or sheared?"

Also it's probably cheaper to manufacture, instead of machining in a full permanent key on the crankshaft, you just machine a little slot and insert a separate key piece during assembly.

 

https://www.tacomaworld.com/threads/1gr-fe-crankshaft-question.664739/
this is the thread I look at it seems so. Either way idk if I’m equipped to be doing the repair myself. Anyone with any past experience with this crankshaft and the keys? I know y’all were talking about someone specific earlier

 

@Torspd