input shaft bearing/oil seal question

garfieldthecat

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I have a quick question I hope someone with more experience can help me with: In the FSM the guidance is to install the input shaft bearing before the oil seal that I believe seals the crankshaft into place on the cylinder block (Image below). Is this sequence (input shaft bearing first, oil seal second) prescribed because the oil seal can be broken or knocked out/loose when installing the input shaft bearing? Can the input shaft bearing be installed subsequent to the oil seal without causing future oil seal problems? I have an engine that had new seals put in but the input shaft bearing still needs to be installed. Is there any best way to install it now that the seal has already been installed? Thanks for any insight you might be able to share.

Also, how necessary are those SSTs pictured to install the bearing and seal? Thanks

1654417255599.png
 

OSS

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Nobody (almost nobody) uses Toyota SSTs for anything except maybe the steering knuckle centering SST. Mostly because they’re not available and usually something else or a different method will work.

If that seal driver SST was used as shown in the manual to drive in the seal, it would use the input shaft pilot bearing for centering. That’s why the manual says to install the bearing first.

The (arguably) best way to install the rear main seal that will give a guaranteed perfect installation is to remove the oil pan. Once the pan is off, the seal can easily be installed (perfectly) just using your fingers.
 

garfieldthecat

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Nobody (almost nobody) uses Toyota SSTs for anything except maybe the steering knuckle centering SST. Mostly because they’re not available and usually something else or a different method will work.

If that seal driver SST was used as shown in the manual to drive in the seal, it would use the input shaft pilot bearing for centering. That’s why the manual says to install the bearing first.

The (arguably) best way to install the rear main seal that will give a guaranteed perfect installation is to remove the oil pan. Once the pan is off, the seal can easily be installed (perfectly) just using your fingers.


Thanks @OSS Can the input shaft bearing be knocked in with a socket of similar size? What's a good lube to use to help it along? I recall reading a thread where someone said to use a lube that won't gunk up the clutch friction plate, but I can't find the thread. Suggestions welcome in this regard please. Thanks!
 

OSS

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Can the input shaft bearing be knocked in with a socket of similar size?
Yes-
The input shaft pilot bearing is just tapped in completely dry.

Use a socket that’s the same diameter as the OUTSIDE bearing shell (race). You don’t want to apply any force to the inner central race.

I don’t remember what socket size fits, but one of them will be a perfect size.
Just tap it in lightly along is outer edge until it grabs - then keep on tapping it in straight.

I’ve done it maybe five times on other cruisers and it’s always been an easy procedure. Nothing special.
Just stay away from the inner race.

But before you tap it into the crank, do a test fit over the transmission input shaft to see how it fits.
If it’s really hard to slip over the tip - that’ll spell trouble when the transmission is getting installed.

And if it’s a sloppy fit (too loose) that’s bad too.
 

garfieldthecat

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Thank you for this. It's very helpful. I tried slipping the bearing over the input shaft of the transmission I am going to be installing with the engine and it doesn't slide down the input shaft tip much at all. I used an emery cloth to reduce some of the diameter of the input shaft tip. I assume the goal of how far down the shaft it should go is to the end of the shaft tip and not merely just beyond the beveled edge at the very tip of the shaft? Thanks 🙏
 

OSS

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The input shaft diameter is the same all the way down the shaft (on a new input shaft). The reason it’s looser near the end is because the bearing interference fit in the past honed it down a teensy weensy bit.

You need the fit to be snug. (But not too tight). You don’t want the shaft to be able to spin inside the bearing race.

See pictures below. This is where the pilot bearing will sit on the shaft when everything is installed.
It doesn’t matter how tight the fit is farther down the shaft - because the bearing doesn’t rest there.

52DB0708-FE10-4E81-8E48-F5D3734D0C49.jpeg
045188E0-FB95-46C0-BDF9-8D836D897F8F.jpeg
 

garfieldthecat

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These photos are perfect. Now I can see how the bearing needs to go on the shaft tip and will test fit again making sure its not too loose. Thank you!
 

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