1987 FJ60 - Need advice hunting down a weird noise!

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87MantisCruiser

Joined
Oct 15, 2025
Threads
5
Messages
18
Location
Maine
Hello! Thanks for stopping in.

Background: This is a 4-speed manual with 217k miles on the clock. However, the motor, transmission, and transfer case were all removed and rebuilt by a Toyota dealership about 30k miles ago (7 years). It is practically rust-free and spent many years in Montana.

The problem: The truck runs great. However, when it is in gear and I am accelerating or decelerating there is an audible whining noise. It is loud enough to be quite annoying. The noise is not there (or not audible) when the truck is idling or rolling in neutral, even at highway speeds. If I am in gear, I can also get the sound to go away when I put just enough pressure on the gas pedal to be neither accelerating or decelerating.

UPDATE: As I mentioned, the whine occurs when in gear in both 2wd and 4wd drive. In an effort to isolate the issue further, I locked the hubs but put the transfer case shifter into neutral to disengage the drive shaft. I then put the truck into first gear and took my foot off the clutch, as if I were driving. No whine. To me, this suggests the problem is with the transfer case or driveshaft.

Solutions I have tried that did not help:
  • checking and topping up trans and TC fluid (I am also going to add one of shipmag's trans to tc hoses as the tc was low and the trans too high)
  • putting truck in 4wd hi and lo and then back to 2wd
  • checking and topping up power steering fluid
  • adjusting/rubberizing the dust shield on the transfer case output shaft
  • Greasing driveshaft u-joints
Solutions I have ordered parts for:
  • trans shift lever seat
  • the 3 crank belts
Solutions I have read about:
  • idler shaft in the trans (this appears to be the most common suggestion when I searched threads, but the trans was recently rebuilt so it just seems unlikely)
  • power steering pump (just seems unlikely since the sound does not occur when I am driving in neutral or with the gas pedal barely depressed)
Thanks in advance for any help! Video of sound:

 
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How are the driveline u joints?
 
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Is it worse in specific gears or it is the same across all gears? Since you mention you needed to add fluid to the tcase it seems the seal between the case and trans has failed and therefore you could have slightly cooked one of the tcase bearings letting it run low on oil.
 
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Throw out bearing riding on the pressure plate?
Pull the inspection cover off and verify how your clutch is adjusted. If it was recently rebuilt, that adjustment could be off.
 
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PBcuiser said:
Is it worse in specific gears or it is the same across all gears? Since you mention you needed to add fluid to the tcase it seems the seal between the case and trans has failed and therefore you could have slightly cooked one of the tcase bearings letting it run low on oil.
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It is largely the same across all gears. Agreed on the seal failing, hopefully the shipmag hose will help me with that particular problem for now.
 
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87MantisCruiser said:
It is largely the same across all gears. Agreed on the seal failing, hopefully the shipmag hose will help me with that particular problem for now.
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You don’t need the hose if fluids aren’t migrating.
Pull the fill plugs and you’ll know if they are.

Even so, I’m skeptical the noise is fluid related.
 
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RevISK said:
You don’t need the hose if fluids aren’t migrating.
Pull the fill plugs and you’ll know if they are.

Even so, I’m skeptical the noise is fluid related.
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I think the fluids are migrating since the tc level was low but the trans level was high. I evened them out and am driving it for a bit before I re-measure. But, like you hypothesized, the noise remained (and remained unchanged in volume or intensity) after I evened up the oil levels
 
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chptuls said:
This sounds like the mainshaft bearing is going bad. I think those are the typical symptoms of it going out/warn.
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Doesn't that seem unlikely though, considering the recent rebuild by a Toyota dealership? Or are the commonly installed incorrectly/go bad. I have the receipts and all parts that went into the rebuild were Toyota OEM
 
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Start with what you can see or access, I still think it’s worth spending a few minutes verifying the clutch adjustment.

As for a dealer doing a job perfectly, Ha… especially on these ol’ grrls.
 
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87MantisCruiser said:
Doesn't that seem unlikely though, considering the recent rebuild by a Toyota dealership? Or are the commonly installed incorrectly/go bad. I have the receipts and all parts that went into the rebuild were Toyota OEM
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I didn’t see that part in the op, I would say yes, could be unlikely. This just sounds like the symptoms.
Do a search on YouTube and you can hear the sounds of input shaft bearings going bad in videos. I think I’ve seen one with an fj40 that was really load.
I’ll see if I can find video and post.
 
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I found the video, but I’m an idiot and can’t seem to copy and paste URL while on the phone.

Search for fj40 input shaft bearing. Should come right up.
 
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UPDATE: tonight I think I narrowed the issue down. As I mentioned, the whine occurs when in gear in both 2wd and 4wd drive. In an effort to isolate the issue further, I locked the hubs but out the transfer case shifter into neutral to disengage the drive shaft. I then put the truck into first gear and took my foot off the clutch, as if I were driving. No whine. To me, this suggests the problem is with the transfer case or driveshaft. Thoughts?
 
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Running the transmission with the transfer in neutral is not a good diagnostic as there is no load on the gears.

It helps when describing a symptom to state when it started.
 
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