2F Crank Repairable?... and Other Questions

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Sheared the key. Pulley is wallowed out and is garbage. Timing gear is grooved badly.

Any opinions on the crank? Besides the obvious gouge it’s lost material around the entire diameter where the pulley sat & spun.
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Gretsch

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A slight hi-jack here on the topic at hand. Does anyone know why/how this occurs? How the key gets sheared like this? Is it improper installation of the pulley or just that the crank gives way under stress? Wobbling HB/pulley? Just poor design? Is there some way to know this happened without taking the HB/pulley off and discovering it? I have seen this happen to several folks on here over the years, so it does not seem to be an isolated situation. Not common but not altogether uncommon either. Just curious if there was some known reason this could occur. Again sorry for the hi-jack. Thanks in advance for replies.
 

OSS

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I dont know why but I always like to guess...
Since we've seen this happen several times on different 2Fs, obviously the key in the crank is insufficient for the job when things get tough
Maybe decades of constantly changing velocity with a heavy harmonic balancer can slowly loosen up the key/groove to the point where it develops a tiny bit of play. Once it's loose, it's only matter of time before it slowly makes the gap wider and wider as it wears it away. Eventually the slop gets so large that the inertia of the balancer acts as a battering ram on the key which eventually shears the fatigued metal.

But I'm just guessing and am probably wrong. It seems that it would be prudent to replace the harmonic balancer at 150-200K miles to prevent this from ever happening.
 

The Machinist

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I dont know why but I always like to guess...
Since we've seen this happen several times on different 2Fs, obviously the key in the crank is insufficient for the job when things get tough
Maybe decades of constantly changing velocity with a heavy harmonic balancer can slowly loosen up the key/groove to the point where it develops a tiny bit of play. Once it's loose, it's only matter of time before it slowly makes the gap wider and wider as it wears it away. Eventually the slop gets so large that the inertia of the balancer acts as a battering ram on the key which eventually shears the fatigued metal.

But I'm just guessing and am probably wrong. It seems that it would be prudent to replace the harmonic balancer at 150-200K miles to prevent this from ever happening.
This is pretty much spot on. I'd add that as the harmonic balancers start to get old and the rubber starts to fail they can tend to get a bit of a wobble, which is ultimately what ends up hammering the keyway. I think this can be made slightly worse by overtightened belts. The rivets in the pulley can also fail sometimes which doesn't help.

Having had this happen on my truck, I'd say that if the harmonic balancer is wobbling, you should probably try to replace it.
 
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A keyway and key is a mediocre way to retain a hub on a shaft, as Jeep found out with their infamous keyed rear axles in the 1970s. Ideally, the crank and harmonic balancer would be splined, which would be a lot stronger, but this expensive and a key will work for most of the owners as long as most of them care.
 
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Got the engine out and torn down today. It has about 80k since the full rebuild I did in 2013 (head overhauled including new seats and resurfaced, block resurfaced, bored [.05], honed, new pistons, reconditioned rods, new rings, bearings, new camshaft and bearings, new lifters, crankshaft grind, main bearings... Builds - The Masochist Build - https://forum.ih8mud.com/threads/the-masochist-build.774375/page-2 )

The engine ran strong before this crank issue. I debated whether or not to pull the head. One deterrent was I understand quality OEM parts are limited (I was told by the local dealer back in 2013 that the kit had been discontinued and that I got one of the last OEM complete engine gasket kits available) In the end I decided to pull everything apart and inspect while I have the engine out.

Besides the damaged crank tip the only problem I found was cyl #1exhaust lifter had some subtle pitting. The lobe on the cam looked like it had some micro-pitting as well, but seemed to mic out the same as all the other lobes. I also found the cam bearings seemed a bit worn. Other than that everything looked GREAT! The cylinder walls still had all the crosshatch from honing with only few minor scratches. The rod and main bearing inserts looked almost new!

So unless anyone has major concern, and depending how much it'll cost me, because all the journals and bearings are so healthy I think I'm going to try and have the crank repaired. Supposedly there is a place a hour south in Salt Lake City that does that kind of repair. I'm going to make some calls Monday...

Looking for feedback on the following:

1. It appears OEM head gaskets are still available? I'll definitely be going OEM on head gasket if I can get one, but what about the rest of the gaskets? Any Ideas on what is the best quality complete engine gasket kit to buy these days?

2. The crank timing gear will need to be replaced. Must I replace the mating cam gear also?

3. What is the best move on Harmonic balancer? I found new made by Dayco or Dorman? Any opinions?

4. Bummed about the cam. As I recall the worn out OEM was replaced with an ITM. I'm going to get the machine shop's opinion, but wondering if anyone has an opinion what my best move is on the cam issue?

5. My understanding is minor pitting or "spalling" on lifter surface is typically caused by moisture/corrosion. Because the rest of the lifters/cam lobes still look like new I'm inclined to believe something like that maybe what caused the problem on the one lifter that had spalling? I've been using Mobile-1 15w-50 (understand it has extra zinc) and adding a quarter bottle of Riselone Zinc with each oil change. Any ideas?

6. Again, no major gouges, but only a few minor scratches in the cylinder walls you can barely feel with your fingernail. I'm debating whether or not to pull the pistons, run a ball hone, and replace the rings, or leave well enough alone. Ring set is like $50. Any thoughts on this?

7. It's registered as an antique, so I no longer need emissions. I eliminated the smog pump 6-years ago. All the other smog gear is in place. The thing runs good. To de-smog or not to dl-smog? Any recommendations?

8. When I had this apart back in 2013 I sent the carb to @FJ40Jim. Took a while to get it back, but he did a great job! Figure I might as well have it gone through again while it's off. I sent him an email and haven't heard back. Anyone know if Jim C is still doing carb overhauls?


Any shared wisdom, or even half-baked ideas are appreciated, Thanks guys!
 
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OSS

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80K on the rebuild and all you could find are a few microscopic scratches on one cam lobe and lifter face? At that rate of wear, the engine will last 1 million miles. Or to put it another way--- the engine will outlast you, the frame and the sheet metal.

I never bought gadget kits for anything even when they were available decades ago. It's not hard to look up each gasket and get its part number from online Toyota parts diagrams.

Removing some emissions parts definitely de clutters the engine bay if it's done correctly. What most people do unfortunately is go step by step through that damn "my desmog" PDF and rip way too much good stuff out of the engine bay, then come back to this forum asking questions why the engine isn't running so well.
I hated looking at my engine bay when all the smog stuff was installed (for CA). It would bum me out. After the smog test I'd remove it all again for the next two years so I could sleep better at night. Needles to say I got pretty good at removing and replacing it all every two years. Did that 14 times - geezus.

Typically any high mileage gear that needs to be replaced should have its mated pair replaced at the same time too to achieve meshing nirvana. If only one gear is replaced, there will be a war going on between them - each one trying to wear the other one down faster. But one gear replacement isn't a death sentence, usually lubricated gears that were matched pairs never wear out- so unmatched pairs will wear faster but still probably outlive something else.
 
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I dropped the crank, block, head, and cam off at the machine shop. Same guys who did the machine work last rebuild, and they were also pleased by how everything was looking. After consulting with the machinist I'm feeling good about having the crank repaired ($150).

After conversation with machine shop and considering what @OSS had to say this is where I am with all my questions:

1. It appears OEM head gaskets are still available? I'll definitely be going OEM on head gasket if I can get one, but what about the rest of the gaskets? Any Ideas on what is the best quality complete engine gasket kit to buy these days?

As per OSS's comments that triggered feelings of inadequacy for bing such a lazyass all these years and just buying the "gadget kit", I spent 40 minutes with the Toyota parts clerk and I think we picked out all the gaskets (and hoses) I'll need. Low and behold pretty much everything was available! Thanks OSS!


2. The crank timing gear will need to be replaced. Must I replace the mating cam gear also?

New cam gear is $30. After the additional $G's going into this again my wife is going to divorce me anyway. 30 bucks isn't going to make a difference.


3. What is the best move on Harmonic balancer?

The options I've found are:

RockAuto (Dayco - new) $350
O'Reilly (Dorman - new) $350
Napa (Napa Solutions - new) $600
CruiserYard (OEM - used & looks kinda rough) $275

Kinda stuck on what to do here :hmm:


4. Bummed about the cam. As I recall the worn out OEM was replaced with an ITM. I'm going to get the machine shop's opinion, but wondering if anyone has an opinion what my best move is on the cam issue?

Cam bearings look a little rough too so at the advice of machinist going with a new cam & bearings


5. My understanding is minor pitting or "spalling" on lifter surface is typically caused by moisture/corrosion. Because the rest of the lifters/cam lobes still look like new I'm inclined to believe something like that maybe what caused the problem on the one lifter that had spalling? I've been using Mobile-1 15w-50 (understand it has extra zinc) and adding a quarter bottle of Riselone Zinc with each oil change. Any ideas?

Based on OSS's speculation that, given the current rate of wear, my great grandchildren will be driving my 60, just going to keep lubricating the way I've been lubricating :meh:


6. Again, no major gouges, but only a few minor scratches in the cylinder walls you can barely feel with your fingernail. I'm debating whether or not to pull the pistons, run a ball hone, and replace the rings, or leave well enough alone. Ring set is like $50. Any thoughts on this?

Again, on top of parts, machine work, and divorce attorney fees whats another $50 for a set of rings


7. It's registered as an antique, so I no longer need emissions. I eliminated the smog pump 6-years ago. All the other smog gear is in place. The thing runs good. To de-smog or not to dl-smog? Any recommendations?

Desmogged 14 times @OSS? I'm thinking you should create a PDF if you haven't already!


8. When I had this apart back in 2013 I sent the carb to @FJ40Jim. Took a while to get it back, but he did a great job! Figure I might as well have it gone through again while it's off. I sent him an email and haven't heard back. Anyone know if Jim C is still doing carb overhauls?

Still haven't heard back from @FJ40Jim . Hope the guy is still around... But anyway, unless someone else knows of another carb whisperer out there I'm going to attempt the carb overhaul myself. Yikes. Just ordered a carb kit from CO.


Still very open to any opinions/advice. Thanks guys.
 
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tmxmotorsports

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Dont think its an rv camshaft its slightly different than stock . I installed it in a customers 84fj60 I can't really say if its a gain in hp or anything 60 wasn't running when it arrived at my shop been a while sense I have deiven a stock fj60 driven ls swapped 60s and I have a 62 . The camshaft worked so did the lifters so far so good turn around time not to bad either im on the far east coast and they are west coast price was fair also. This is the only writing on the box they sent the camshaft back to me in they may just be reference numbers order numbers. If your interested give them a call.
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Spike Strip

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Is the delta cam a rv grind? Or anything above stock? And how do you like it?

Delta Cams will sell you a RV grind or stock. Your choice.

FWIW, Melling still sells a USA made stock cam that's very good quality

MC803


The HBs are all going to be Powerbond (Dayco) aftermarket unless you buy a new Toyota.
 

Spike Strip

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I used the Melling in my rebuild 10 years ago. IIRC it's what Jim C recommended. RV cams drop your torque curve down at the expense of higher RPM horsepower. I didn't want that, I wanted an all-around curve just as Mr T's engineers designed. I wanted durability, not the fragility that comes from trying to squeeze every last bit of oink outta a pig... Would be good I suppose if truck is most of the time off-road. If it's a DD or once-n-a-while offroader, then stock valve timing is best. Also your idle may be bumpy with an RV. New OE and OEM lifters are available.
 

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