You should have the same power steering unit as all the other 3rd Gen years as far as I know. There are differences between the model years but I haven't heard the later models have a different power steering pump and reservoir. If yours looks the same as the one in the video, it's a pretty safe bet the o-ring is going to work.

Here is a video I just put together of installing/swapping the front diff/clamshell that I got from ECGS.
I installed 4.88's
Hope you find useful.
Let me know if you have any questions
YouTube

Dude, you should have looked at the video we made for this first. It might have made life easier for you getting the diff out. We had the same struggle getting the diff out and back in. Since then, I've pulled a front diff another 4 times and there's two tricks to getting it out and back in easier. #1 is to disconnect the driver side motor mount, and jack up under the oil pan to give you more room. #2 is to disconnect the metal vacuum and breather line from the top of the diff because those metal lines want to hook the power steering lines as you're trying to get the diff out. Once the metal lines are loose, I turn the line assembly 90 degrees so they're out of the way of the power steering lines. If you do those 2 things, the diff comes out without a fight. We listed these two techniques in a pinned comment for the video we made.

I'm surprised how easy you got that stub shaft out. My buddy Fred and I tried the 2 prybar technique that you used and couldn't get the damn thing to budge. I think maybe you had pry bars with thinner ends to get under the gear better. Anyway, good job getting it done.

I put this video in the table of contents.

I was prepared to do all that as well (remove the motor mount and jack up the engine), but I think having taken off the front diff mounts prior to removal definitely helps and may make it unnecessary. @mtbtim has way more experience with these than I do, so if you're struggling too much with removal, then you should follow his advice.

Also, as for removing the 4 LBJ bolts: I would advise against that for anyone unless you are replacing them. Though it's not stated in the FSM, after reading many instances of these bolts backing out after removal and reinstallation, it's pretty clear to me that they are most likely torqued to yield. This means that they should be replaced with new bolts any time they are removed. Ask @AssBurns how he knows.

I haven't tried the technique of removing the diff mounts prior to removal so I don't know how much that makes it easier. From my experience, the companion flange on the diff strikes the bell housing and the oil pan gets in the way too. Disconnecting the motor mount is easy for me because I've done it several times now so I think I'd stick with my technique to jacking up the motor because it eliminates the fight with bench pressing the diff over and over again. With the motor jacked up a bit, the differential literally falls right out without a fight.

Tim I watched your video and to be honest, missed some of the steps you mentioned. It could have been much easier! I was just so damn excited! At the end of the day, I got it done and I love the 4.88's!

As always, appreciate you and the experience you provide. I have watched a LOT of your videos.
Cheers

as a new owner of a 98 4runner, this post was very helpful. thank you.

Well, it's actually a "thread" and not a single post but it's good to hear you have found the thread helpful. Happy Wrenching!

An issue I'm having which I can't find a thread for on the forum is sometimes when I'm turning left at low speeds(entering driveway, turning into a parking spot), my steering wheel gets stiff/borderline stuck and I need to apply extra force to turn the wheel. This only happens when I'm turning left, at low speeds, but it doesn't happen all the time. A coworker is suspecting a bad bushing somewhere in the front end. My PS pump isn't whining. I've owned the truck for roughly 2 months and the PS fluid level has remained the same, so I don't suspect a leak.

Other threads I've read deal with stiff steering all the time or when cold. Some things mentioned in those were lower ball joints going bad, bushings on sway bar going bad/worn out. Any other area I should be looking at? When I had the front end up on jackstands and turning it lock to lock, I could not replicate the issue.

I just flushed the power steering fluid, and cleaned out the mesh screen at the bottom of the reservoir yesterday, and while the steering seemed somewhat smoother, this issue did not go away.

sorry for the long post, I figured the more details the better.

Does it get easier to turn if you apply more gas when its "stuck"?

I'm not sure. I don't recall trying apply more gas. Given that I'm entering a parking spot/driveway, I'm usually coasting for the most part.

Sent from my SM-G965U using Tapatalk

Try giving it a little more throttle next time it happens to see if it helps make it easier to turn. My thinking is the combination of low speed causing more turning resistance at the tires and low engine rpms causing lower power steering pump pressure and volume is making it feel stiffer sometimes. Just a theory though.

Thanks for posting this videos, Really helps

This sounds like the symptoms people speak of just before LBJs fail. Look into this NOW! May not be the issue but make sure in a hurry. If one fails it’ll be expensive.

After driving for a couple weeks, giving it throttle doesn't make it any easier.

I'm going to be looking into this hopefully in the next couple weeks. Luckily it's not a DD, so it will just sit.