I'm certainly not an expert but I would say they don't look great, but they also don't look like a source of clunking.
1HDT Bad Clunk and Vibration: Stranded (1 Viewer)
- Thread starter CaptBeardilocks
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I don't have too much to add since I don't know that engine well, but your initial description had me thinking clutch / flywheel.
Also, I know you've mentioned new parts before, but new doesn't mean good. New parts can absolutely fail prematurely, or be bad right out of the box.
Good luck!
-Rob
Also, I know you've mentioned new parts before, but new doesn't mean good. New parts can absolutely fail prematurely, or be bad right out of the box.
Good luck!
-Rob
- Thread starter
- #23
Absolutely they can fail right out of the box. Never had that with Toyota parts yet but it’s definitely happened to me.
Ok, so all 6 are commiserate with the one shown previously. Adding a few more pics.
Anyone have ANY idea how they could get this thrashed in 4k miles? Oiling? Bad main bearings? Bad job spec-ing these and they were too small? (Parts can be bad sometimes and so can my judgement)
Ok, so all 6 are commiserate with the one shown previously. Adding a few more pics.
Anyone have ANY idea how they could get this thrashed in 4k miles? Oiling? Bad main bearings? Bad job spec-ing these and they were too small? (Parts can be bad sometimes and so can my judgement)
- Thread starter
- #25
I did the refresh and I’m as fallible as anyone. Lol. The only internal work I did was the BEBs. Head has not been off.
Would cyl wear speed up rod bearing wear this significantly?
No, but it would be indicative of any oiling issues.
Did you use clean all surfaces and use assembly lube?
- Thread starter
- #27
Yes. Engine was out and upside down on an engine stand when I did the BEBs. Everything was clean and I think I used Lucas assembly lube? Or Lucas oil stabilizer? I can’t exactly remember. It was really really thick.
Engine prob sat for a year before it was started.
I’m def looking for a cause but nothing is apparent at this juncture.
- Thread starter
- #28
Plastigaged all 6 today. All bearings showed clearance on wide end of spec, about ~.075-.080mm. Max clearance is .10mm according to the FSM.
I checked my notes from the install and the standard size Taiho bearings plastigaged at .050mm when they went in. (Assuming I can trust my notes, lol.). Could that be too large a gap abs cause this??
So the Taiho bearings took a .025mm beating in 4000mi? I’m still at a complete loss as to how.
I was running Rotella T5. Any chance that’s too thin an oil for the motor in the southern US?
I checked my notes from the install and the standard size Taiho bearings plastigaged at .050mm when they went in. (Assuming I can trust my notes, lol.). Could that be too large a gap abs cause this??
So the Taiho bearings took a .025mm beating in 4000mi? I’m still at a complete loss as to how.
I was running Rotella T5. Any chance that’s too thin an oil for the motor in the southern US?
FJBen
SILVER Star
some possible thoughts.
Damaging Action:
- Because, a bearing with insufficient crush is loose and therefore; free to work back and forth within its housing.
- Because, of the loss of radial pressure; there is inadequate contact with the bearing housing.
- As a result, impeding heat transfer away from the bearing.
- Also, the bearing overheats, causing deterioration of the bearing surface.
Possible Causes:
- Filed down parting faces, in a mistaken attempt to achieve a better fit; thus removing the crush.
- Due to dirt holding open bearing caps.
- Insufficient torqueing during installation; (be certain bolt doesn’t bottom in a blind hole).
- The housing bore was oversize, or out of round.
- Over use of shims.
Engine Bearing Clearance Corrective Action:
- Clean mating surfaces of bearing caps and inspect for nicks and burrs prior to assembly.
- Check journal surfaces for excessive wear and regrind if necessary.
- Check the size and condition of the housing bore and recondition if necessary.
- Correct shim thickness (if applicable).
- Install new bearings using correct installation procedures (never file bearing parting faces).
Here is talking about too much clearance.
However, a further increase of clearance leads to a decrease of min. oil film thickness. This effect is caused by a localization of the oil pressure to a smaller area of the bearing surface. The non-homogeneity of the oil pressure distribution is characterized by the ratio:
the average load applied to the bearing surface (5,100 psi or 12,000 psi in our calculations)
the peak value of the oil pressure
Besides a decrease of min. oil film thickness, the non-
homogeneous oil pressure distribution caused by excessive clearance may result in fatigue of the bearing material in the area of peak pressure. This phenomenon is known as knocking.
As seen in the graphs, clearance exceeding 0.003” (.076mm) may result in substantial non-homogeneity of the oil pressure distribution.
What was the injector pump timing set to? Too advanced can flog big ends in no time, even worse on these old girls with sensitive big ends/timing specs to start with and again even worse if you lug them hard in low revs have high oil clearance and poor oil quality. I think this is why in the later 1hdt (92 onwards) they changed the piston bowl and changed both base pump timing and internal timing to give a smoother combustion and make it easier on the big end bearings. Early pistons small bowl is 1.29-1.34mm and late wide bowl is 1.18-1.24mm, from what I have gathered with my couple of failures and talking to a couple of engine builders and pump builders is always set to the less advanced setting with these motors.
chapel gate
GOLD Star
i would check the crank journals for ovality. your bearing sizing was bang in the middle of spec, pretty much perfect imo.
ive never heard of a problem with anyone using standard sized bearings. there are multiple score marks on the bearings, including what looks like two particles have picked up and embedded themselves in the bearing.
is the crank scored? what were the bearings like you replaced?
ime bad bebs "knock", when they knock epic failure is imminent..
removed these recently from a 92. motor ran and sounded great...
ive never heard of a problem with anyone using standard sized bearings. there are multiple score marks on the bearings, including what looks like two particles have picked up and embedded themselves in the bearing.
is the crank scored? what were the bearings like you replaced?
ime bad bebs "knock", when they knock epic failure is imminent..
removed these recently from a 92. motor ran and sounded great...
Last edited:
- Thread starter
- #32
Injection pump timing was set to the tag that came on the freshly rebuilt pump from GTurbo. Which I don’t have in front of me at the moment unfortunately…
So not set aggressively on purpose by me. But I have no idea if that spec from GTurbo would be considered aggressive.
- Thread starter
- #33
I’m currently trying to track down a micrometer to check for anything out of round. Another fun part about trying to sort this out on the road away from my shop in a rural area…. At least it’s a pretty spot to break down. Lol.
Crank shows no scoring. A bit of… a pattern you can see in the right light on one journal (see below) but not all of them. It feels completely smooth, so I’m not sure if it’s from heat or what. BUT it’s just the one and all 6 bearings were damaged fairly evenly this time.
Here’s what the old ones looked like that came out when I got the motor. No clue how old they were.
Hey @chapel gate , you have an nice HDFT I could just swap in instead of all this detective work? Haha!
chapel gate
GOLD Star
to me the bearing damage looks to be from foreign debris. the "damage" is not enough to be causing your clunking.
you could discount this by fitting new bearings, cheap and your over halfway there work wise.
JMO. as we know, diagnosis can be the harder part of mechanicing..
ha ha! she is just fine where she is..
you could discount this by fitting new bearings, cheap and your over halfway there work wise.
JMO. as we know, diagnosis can be the harder part of mechanicing..
ha ha! she is just fine where she is..
- Thread starter
- #35
I’m definitely putting in new bearings. Just trying to decide on standard or .25 under…to me the bearing damage looks to be from foreign debris. the "damage" is not enough to be causing your clunking.
you could discount this by fitting new bearings, cheap and your over halfway there work wise.
JMO. as we know, diagnosis can be the harder part of mechanicing..
ha ha! she is just fine where she is..
I’m also guessing the loud clunk is something else. But have to get it back together to try to track that down.
At this point I’m guessing 3 issues exist in some kind of perfect storm. Lol.
chapel gate
GOLD Star
always have faith in you measuring..
out of curiosity what oil are your running?
- Thread starter
- #38
Rotella T5 15w-40 semi-synth
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So, you didn’t do a crank grind? Just a polish? Or nothing?
I prefer if not doing machine work to put in OEM bearings. Bottom of your block will be stamped with seven numbers. These are your crank bearings size from the factory. You may have a 2222222 or a 2223222 or a 2221222. Never seen anything else. You can order these from Toyota as per the block number stamp. IMHO it is far better than a generic “standard” bearing.
Piston slap can also cause noise. This can come from wrong ring gap size or wasted BEB.
It is unlikely the crank is damaged but if it hasn’t been checked how do you know.
Injector knock can also makes noise. Broken flywheel or clutch as well but usually that will change when depressing the clutch.
Cheers
I prefer if not doing machine work to put in OEM bearings. Bottom of your block will be stamped with seven numbers. These are your crank bearings size from the factory. You may have a 2222222 or a 2223222 or a 2221222. Never seen anything else. You can order these from Toyota as per the block number stamp. IMHO it is far better than a generic “standard” bearing.
Piston slap can also cause noise. This can come from wrong ring gap size or wasted BEB.
It is unlikely the crank is damaged but if it hasn’t been checked how do you know.
Injector knock can also makes noise. Broken flywheel or clutch as well but usually that will change when depressing the clutch.
Cheers
- Thread starter
- #40
I didn’t do anything to the crank other than clean it up and put the Taiho bearings in.
Are the numbers stamped on the block or the crank? The FSM talks about getting numbers from the crank and the con rod and adding them together. Some folks have suggested going 1 size over that to compensate for wear? Do you guys just put the factory sizes in?
