1HDT Bad Clunk and Vibration: Stranded (1 Viewer)

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I pulled one cam bearing cap. Doesn’t look horrible up there. Let me know if anyone disagrees. Lol. But I don’t think it looks bad enough to say I have systemically low oil pressure.

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Is it supposed to be stepped like the circled bit? And it kind of looks like it's splitting where the arrow is.

I don't know anything about these engines, so that may be a dumb question. Hope you can get back on the road soon.
 
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Is it supposed to be stepped like the circled bit? And it kind of looks like it's splitting where the arrow is.

I don't know anything about these engines, so that may be a dumb question. Hope you can get back on the road soon.
Thanks for looking so close. I had to take a look and double check. Each cap has a small channel there on one side. No clue why. But apparently deliberately.
 
I'm curious how your project is coming along.

I have virtually zero time to reply to anything on 'Mud, and not enough time to get to all the emails I get on any one day. Sorry, it's just life running a one-person business.

A few notes now that I've seen this thread.

Your rod bearings are not worn. The scratches, as one or two others have noted, is from dirt in the engine or that got onto the bearings during installation. It's not that uncommon when this kind of work is done in a shop space that's not super clean, and the parts are not carefully cleaned before assembly after plasti-gauging. They are not supposed to be scratched, but it's also not the end of the world.

There was some mention of using ARP studs.

They are a great idea, and can be re-used vs the stock style TTY bolts that should be tossed in the bin each time. They provide about 40% better clamping force over the stock style bolts - which is a huge advantage if you're running more boost pressure.

I keep the ARPs in stock when I can get them, but they are hard to get due to low production volume and high demand and usually sell about as fast as I can obtain the very limited number that make their way to me. I have one set available now, two more are in transit along with a couple of sets of 1HD-FT/E ARP studs, and then there will be no more until at least mid July.

I would like to find out what the solution to your clunking noises are. It's very perplexing when these kinds of things happen, and very difficult to diagnose over email, forum posts, or a phone call.


Good luck with your progress on finding the answers.

~John
 
Your rod bearings are not worn. The scratches, as one or two others have noted, is from dirt in the engine or that got onto the bearings during installation. It's not that uncommon when this kind of work is done in a shop space that's not super clean, and the parts are not carefully cleaned before assembly after plasti-gauging. They are not supposed to be scratched, but it's also not the end of the world.

Maybe not for 200k but they're worn/scored more than they should be for 4k miles. The ones pulled from my 200k km FTE looked significantly better.

For reference. These have hundreds of thousands of miles on them.

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I'm curious how your project is coming along.

I have virtually zero time to reply to anything on 'Mud, and not enough time to get to all the emails I get on any one day. Sorry, it's just life running a one-person business.

A few notes now that I've seen this thread.

Your rod bearings are not worn. The scratches, as one or two others have noted, is from dirt in the engine or that got onto the bearings during installation. It's not that uncommon when this kind of work is done in a shop space that's not super clean, and the parts are not carefully cleaned before assembly after plasti-gauging. They are not supposed to be scratched, but it's also not the end of the world.

There was some mention of using ARP studs.

They are a great idea, and can be re-used vs the stock style TTY bolts that should be tossed in the bin each time. They provide about 40% better clamping force over the stock style bolts - which is a huge advantage if you're running more boost pressure.

I keep the ARPs in stock when I can get them, but they are hard to get due to low production volume and high demand and usually sell about as fast as I can obtain the very limited number that make their way to me. I have one set available now, two more are in transit along with a couple of sets of 1HD-FT/E ARP studs, and then there will be no more until at least mid July.

I would like to find out what the solution to your clunking noises are. It's very perplexing when these kinds of things happen, and very difficult to diagnose over email, forum posts, or a phone call.


Good luck with your progress on finding the answers.

~John
Hey John,

Thanks for giving your thoughts here. Your time is very much appreciated.

It’s hard to see in the pics but the bearings were noticeably hammered at the tops. I was less concerned with the scratches/wear than with the fact that when installed the bearing plasti-gauged at ~.050mm and when checking them after 4000mi they were now ~.078mm.

Where things stand now is I finally got a full set of factory sized Toyota bearings by reading the crank & caps (I think I got the last 05 bearing on the planet) and just got them in last night. I’m picking up oil today and will attempt a start to see what, if anything, the fresh bearings did.

But I’m no closer to figuring out how the bearing got hammered out so fast. Which is worrisome.

More updates soon. Thanks for all the thoughts!
 
Ah, ok, I see that now - the bearings on the top.

They are always the ones to wear first due to the transferred loading on the piston during the power stroke.

If you have access to a small diameter bore scope, you might want to pull each glow plug and have a look at the tops of the pistons and see if there's been any interference with the cylinder head or valves.

I would fully expect your new rod bearings to suffer from the same fate in fairly short order as the first ones as there's been no actual solution to the problem that caused the issues you're facing.

I don't hear back from clients very often, however after selling literally hundreds of sets of rod bearings over the years there has only been the odd concerns expressed, and never anything about a wear or noise problem - like once where the Std. bearings didn't mesasure properly (engine had been apart before and was machined), and one where the guy wanted to get a split sized bearing such as the ACL Race Series offering of 0.025 to solve an oil clearance issue.

The Taiho rod bearings are an OEM bearing. You can pay a lot more for the Toyota red and white box vs the Taiho red and white box, though there is the supposed advantage of the numbered (fractional) sizes differences with the Toyota bearings.

Since we have a bit of a head start on 1HDT importing here in Canada vs the USA, we have also been seeing repeat rod bearing replacement jobs and I can't recall of one set being bad other than some scratches from tiny dirt particles.


~John
 
Just read the whole thread, and wish I could be of more help, but let me throw my thoughts on the pile!

If it's at all helpful, my 1992 HDJ81 has a decent shimmy / kerthunk every time I shut it off. Also, I can hear something (Exhaust?) bang against something else when it does that (hollow metal bang). I believe it's engine / trans mounts, because the whole truck shimmys at shutdown. Mounts are the only thing that make sense to me.

That being said, I don't have any vibration during driving (at least nothing outside of normal for a 30 year old diesel truck).

Another anecdote just to add to the spitballing nature of this thread.

I had a 1998 VW GTi that developed an intermittent engine knock type sound. The motor mounts were very sloppy (and the car had a huge cam in it, so it was lopey) and I assumed they were banging, so I replaced them all with denser poly mounts. Sound was still there. I pulled the head because I had done a HG a few months ago, and was thinking it was piston slap or possible crank wobble. All was perfect. Put the head back on, still had the noise. I finally pulled the trans to look at the clutch, and found one bolt holding the pressure plate to the flywheel had sheared. The noise I was hearing (it would come and go) was because the bolt would slide out, and knock against the bellhousing casting, and then slide back into it's hole with no particular rhyme or reason as far as timing. It would sometimes knock a few times at idle with the clutch in, and sometimes knock under load, or on deceleration. Almost totally random. I actually still have the bolt, and I made it a keychain as a reminder to troubleshoot properly.

I think a stethoscope would be the next move. I can hear pretty good with a long flathead screwdriver pressed into my ear. It will pick up the resonance of whatever I place the screwdriver tip on and works in a pinch in lieu of an automotive stethoscope, but those are cheap at the auto parts store.

Good luck!
-B
 
The "clunky" shutdown on the 1Hx series of engines has to with with the fuel-cut shut off being used to end combustion. The engine is experiencing full compression while it's being shut down, and as the rotating assembly is coming to a stop, it will cease rotating as it 'hits' the start of a compression cycle on one cylinder.

Compared to an engine that uses an intake butterfly to stop the engine through air starvation such as a 12HT, or a 2H with an automatic transmission, the shut down will be much smoother and less clunky feeling as there's very little air in the intake and so the compression stroke has much less resistance against it.

This kind of shut down, the fuel cut off type, can cause some engines to move a fair bit in the engine bay and stuff can shake - like bad engine mounts, exhaust piping that's close to the frame or body work - that you might not hear so much when the engine is running.

Vibration during running is something else, and that needs to be sorted out.


~John
 
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The "clunky" shutdown on the 1Hx series of engines has to with with the fuel-cut shut off being used to end combustion. The engine is experiencing full compression while it's being shut down, and as the rotating assembly is coming to a stop, it will cease rotating as it 'hits' the start of a compression cycle on one cylinder.

You make a good point. I'd imagine some other folks might not be too familiar with how old IDI diesels work. If they aren't broke, they literally keep running until you run out of diesel, or stop giving the fuel stop solenoid +12v!

I've had at least 5 80s VW diesels, all of which use a nearly identical Bosch VE pump and fuel stop solenoid, so I'm familiar with what you describe.

It's interesting that some of the Toyotas use an intake butterfly to kill the engine. That would be a great way to prevent runaways if the engine ingests oil or you have a fuel problem!
 
Thanks for the replies guys. I appreciate all the thoughts and opinions.

I just got oil in it to crank it over. My truck is currently doing that thump/clunk when just cranking the starter, fuel shut off & not running.

Getting under it now to try to narrow it down while someone else cranks.
 
Should we start some kind of a betting pool here and wager something on our armchair diagnostics? ;)

~John
 
I'll bet someone a beer that its a bad muffler bearing?
 
Well guys…

I always figured it was likely that I had multiple issues. Look like at least one of them was bloody stupid. :rolleyes: Hahaha.

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So yeah…. THAT was banging on start up. Wedged in there like a bastard. Bloody hell. Explains my t-case vibration I was picking up before the clanking started too.

Obviously this doesn’t explain my bearings hammering out in such a small amount of miles. But it was definitely the universe’s way of getting me to look at those and see it.

So I’m not sure what’s next. I need to put some miles on it and see what everything feels like. See if anything still feels off.

But at the very least, that’s my shut down and starting rattle/banging.

PS: That's a homemade 3/8” steel bash plate I made when I swapped auto to manual because of trans mount difference. And that’s one of the reasons it was such a deep banging noise that sounded so terrifying.
 
Well guys…

I always figured it was likely that I had multiple issues. Look like at least one of them was bloody stupid. :rolleyes: Hahaha.

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So yeah…. THAT was banging on start up. Wedged in there like a bastard. Bloody hell. Explains my t-case vibration I was picking up before the clanking started too.

Obviously this doesn’t explain my bearings hammering out in such a small amount of miles. But it was definitely the universe’s way of getting me to look at those and see it.

So I’m not sure what’s next. I need to put some miles on it and see what everything feels like. See if anything still feels off.

But at the very least, that’s my shut down and starting rattle/banging.

PS: That's a homemade 3/8” steel bash plate I made when I swapped auto to manual because of trans mount difference. And that’s one of the reasons it was such a deep banging noise that sounded so terrifying.

Happens to all of us. I had a mysterious clunking sound in one of my rigs for weeks, drove me nuts, re-torqued everything, spent hours underneath it... It turned out to be a 18mm impact socket under my seat banging around.

Either way, it led you to the bearing situation.
 
I always figured it was likely that I had multiple issues. Look like at least one of them was bloody stupid. :rolleyes: Hahaha.

So yeah…. THAT was banging on start up. Wedged in there like a bastard. Bloody hell. Explains my t-case vibration I was picking up before the clanking started too.
Wait, it that just a rock wedged in between your T Case and the subframe / support?
I'm not sure if I should be happy or sad for you!?
-B
 
Wait, it that just a rock wedged in between your T Case and the subframe / support?
I'm not sure if I should be happy or sad for you!?
-B

Well, that was the clunking on start up. I always suspected more than one issue was present based on my symptoms. It still doesn’t explain my BEBs being out of spec after 4,000mi. So there’s still some detective work to be done.
 

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