[3FE] Main crank pulley keeps walking, time for engine rebuild? (1 Viewer)

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Just covering some already mentioned stuff, Get a Torque wrench that can torque the crank nut to spec of 253ft-lbs. Not 252ftlbs, not 253ftlbs. It should not be a guessing game of "Its good enough" or "its close enough." I would ask the shop show me their torque wrench that can reach that high of a torque. They may be a good shop and the building may have had a mechanic that knew how to work on landcruisers but that doesn't mean they've done this job specifically or the guy actually working on your truck knew how to work on old landcruisers.

These trucks already vibrate to hell, or at-least mine does, so unless your truck is harmonizing in the most perfect frequency or shaking a ton then I'd be surprised if it vibrated out at 253ftlbs.

Here are all the reasons that I can come up with on why any nut and bolt would fail.
1. Not torqued to spec.
2. Once been over-torqued and plastically deformed nut/bolt. Elasticity of metal is gone and or threads damaged (this is one reason a tire could fall off)
3. Dirty threads interfering with torque spec
4. Dirty seat interfering with torque spec
5. Threads damaged
6. Bad torque wrench.

The crank nut only clamps the pulley to the crank, It does not pull the crank rather it would float with the crank if im not mistaken.
Its strange how the old one broke the way it did.

Anyway ive already written too much. I think whoever torqued it did it wrong or didn't clean the threads
 
Ok, thread update from the shop. I went over and we talked over some ideas.

One, SOR speedi sleeve does not fit the OEM gasket, it’s not even close and there’s no recommended seal to pair with the kit.

Two, the used harmonic balancer we put on after the first time is very scored.

We’re not exactly sure what’s going on with this engine chewing up balencers. My best guess is that the 2nd walk off scored the replacement balancer when it also chewed through the seal.

The big worry is that there’s a serious internal issue with the crankshaft, though the keyway is clean edged and there’s no play in the crankshaft itself.

We did fix the nut walking off and that’s no longer an issue. Locktite and 253ft/lb is the magic.

I’m leaning towards getting a new harmonic balancer, skipping the sleeve, and using the OEM gasket now that the nut isn’t walking off.

There is a new pulley from Toyota: Toyota Land Cruiser Engine Crankshaft Pulley - 1347061030 | Fred Anderson Toyota, Raleigh NC - https://parts.fredandersontoyota.com/p/Toyota__Land-Cruiser/Engine-Crankshaft-Pulley/63133970/1347061030.html

The alternative is a $200 Dayco HB.

Any thoughts on the best path forward? My guess is we’ve been unlucky with nut walkoffs and that’s been chewing up the balancer. With a proper install, and a new balancer, should that be the fix?

Some pictures of the first and second cranks, along with the crankshaft end.

A52A9B2B-0DAF-4EC4-A35F-BA01EC658EC6.jpeg


1CA79A85-ABCD-48F3-8A55-22D5C5CCE149.jpeg


AC81142E-AAA2-461A-8974-3D13D11C32C9.jpeg


F0ADAC47-7E63-4771-BA48-78CD9A5C9361.jpeg
 
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When I replaced mine a few years ago the rubber on the back of the HB was rotting pretty significantly. The nut wasn’t walking itself off but the pulley was noticeably wobbling. You could see the belts walking in the alternator pulley groove. I used a new HB made in China. I think it was $500 ish?

The woodruff key on my crankshaft broke off at some point in the past and was repaired by the PO. It doesn’t seem to bother anything.

The last time I did this job, I replaced the timing cover gasket again along with the seal. Before torquing the timing cover bolts I installed them finger tight. Then installed the HB and torqued the nut to about 200. Then I tightened a few of the cover bolts to spec and removed the HB so I could access the lower cover bolts and torque them properly. Then I installed and torqued the HB to final spec.

It’s important to get the cover aligned properly or you’ll ruin seals.

I doubt this is the issue, but how does the woodruff key look? Does it fit in the crankshaft tight? And the HB slot?

I’ve wracked my brain a lot thinking about this problem over the years.

Another thing to note is that using thread loc and anti-seize change the torque values because those products act as a lubricant.

Oh, and it’s also important to oil the mating surface of the nut and pulley or it will gouge things and could cause issues with a tight fit. My old balancer was chewed up from installing the nut dry.
 
cps432 said:
When I replaced mine a few years ago the rubber on the back of the HB was rotting pretty significantly. The nut wasn’t walking itself off but the pulley was noticeably wobbling. You could see the belts walking in the alternator pulley groove. I used a new HB made in China. I think it was $500 ish?

The woodruff key on my crankshaft broke off at some point in the past and was repaired by the PO. It doesn’t seem to bother anything.

The last time I did this job, I replaced the timing cover gasket again along with the seal. Before torquing the timing cover bolts I installed them finger tight. Then installed the HB and torqued the nut to about 200. Then I tightened a few of the cover bolts to spec and removed the HB so I could access the lower cover bolts and torque them properly. Then I installed and torqued the HB to final spec.

It’s important to get the cover aligned properly or you’ll ruin seals.

I doubt this is the issue, but how does the woodruff key look? Does it fit in the crankshaft tight? And the HB slot?

I’ve wracked my brain a lot thinking about this problem over the years.

Another thing to note is that using thread loc and anti-seize change the torque values because those products act as a lubricant.

Oh, and it’s also important to oil the mating surface of the nut and pulley or it will gouge things and could cause issues with a tight fit. My old balancer was chewed up from installing the nut dry.
Click to expand...
I think the key has a scratch or two, but it's not out of tolerance. That's a good point about the balancer mating surface, I wonder if it had been reinstalled at some point dry.
 
We ran a check on the crank and while there's a slight movement to it, it doesn't look gone or out of spec. It's really challenging to be sure with the age and mileage. We decided to order a new balancer with the intention to button it up properly. If it blows up again, we'll know for sure it's new engine time.
 
I had some wild thrust play on my crankshaft a while ago, driving it I would never tell besides the grinding noise. it was when I was changing my clutch that I found the issue. What Kind of movement is in your crankshaft?

The main pulley falling off wouldn't even be a shred of concern with the type of play I had as shown in the link Fj60 FlyWheel grinding on the block - https://forum.ih8mud.com/threads/fj60-flywheel-grinding-on-the-block.1089533/post-11899297

What was the reading on the oscillation test? Seems like your on the right track
 
ChaserFJ60 said:
I had some wild thrust play on my crankshaft a while ago, driving it I would never tell besides the grinding noise. it was when I was changing my clutch that I found the issue. What Kind of movement is in your crankshaft?

The main pulley falling off wouldn't even be a shred of concern with the type of play I had as shown in the link Fj60 FlyWheel grinding on the block - https://forum.ih8mud.com/threads/fj60-flywheel-grinding-on-the-block.1089533/post-11899297

What was the reading on the oscillation test? Seems like your on the right track
Click to expand...

I don't think we had any forward/backward play, but I can't remember the micrometer measurements they listed out over the phone. I'll see if I can email them about it.
 
any updates ?

WE need the TEq tech Final on this one bad ......... 🤔
 
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So here's where we're at. I'm driving around the truck this week keeping an eye on things. However, a new harmonic balancer from Toyota seems to have solved our vibration issues, the used one had wobble to it we discovered. It's holding together with the NOS nut and locktite.

What's still not accounted for is why it happened in the first place, so I'm hoping it was a bum repair that walked it off the first time and 2nd was a bad part.
 
TheElegantFox said:
So here's where we're at. I'm driving around the truck this week keeping an eye on things. However, a new harmonic balancer from Toyota seems to have solved our vibration issues, the used one had wobble to it we discovered. It's holding together with the NOS nut and locktite.

What's still not accounted for is why it happened in the first place, so I'm hoping it was a bum repair that walked it off the first time and 2nd was a bad part.
Click to expand...


it's always interesting how when you use NEW OEM TOYOTA Genuine Parts , Follow all the step by steps in the FSM correctly & add some cheap but all important

and indeed in this case a MUST / LOCH-TITE Insurance ...... :)



you did a GOOD Job here btw @TheElegantFox , know that fact ...



(.11) - Copy (2).gif
 
TheElegantFox said:
So here's where we're at. I'm driving around the truck this week keeping an eye on things. However, a new harmonic balancer from Toyota seems to have solved our vibration issues, the used one had wobble to it we discovered. It's holding together with the NOS nut and locktite.

What's still not accounted for is why it happened in the first place, so I'm hoping it was a bum repair that walked it off the first time and 2nd was a bad part.
Click to expand...
My guess is the rubber in the HB was failing. Like taxes and death, it happens to all.
 
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