Leaking axle seal

Hello, I need some advice, and I wanted to see if anyone can help with a leaking axle seal. Sorry for the long post, but I want to explain everything I have been through, so there are not a hundred questions.


I have a 2002 AC 4WD that I purchased recently for my son. (29K miles, one previous owner)


I was doing some upgrades to the suspension and found that the inner CV boots were slinging grease, so I replaced the CV axles and axle seals on both sides. (truck was stock before me owning it)


In the front, to give it a little lift, I installed Eibach adjustable shocks, new Eibach springs, and differential drop. Also, mounted new rack and pinion steering (one boot was leaking), new tie rod ends, new lower control arms, and new adjustable UCA's (SPC). Also, I put on new tires (285/70R17) and rims. I also got it aligned (trusted shop). The guy said it was easy, and it aligned great (all new parts).


I used OEM Toyota axle seals purchased from the dealership. Initially, before replacing seals, they were not leaking. I first noticed the leak on the passenger side, outer axle seal, a few days after installation. As noted above, I never even drove it, b/c I was still working on other items. I figured that I might have damaged the seal when I put it in, so I pulled it back apart. There was no damage to the axle housing, and everything looked really clean.


When replacing the seal (the second time), I was trying to figure out why it was leaking. So I went to the internet for some investigation. After watching videos online and reading forums, I found that I may have installed the seal backward. The OEM seal has metal on one side and rubber coating on the other. I found online it shows that that one person put the rubber on the inside and the other showed it went on the outside. It seems that I may have followed the wrong video. After searching, I found that it looks like the rubber was supposed to be on the outside. That seemed like the correct way. This would put the metal towards the bearing in the housing. After installation, there were no leaks after a few days of sitting in the garage.


Now that the truck was back together, I started driving it. I drove it a few times and again found that it was leaking almost immediately after driving it. So, I replaced the seal again (third time). Yes, I put it back in the same way, rubber to the outside. This time I replaced the CV axle as well (2nd new axle). I just thought that there might be an issue with the new axle, so I wanted to eliminate that as well. I don’t have any sounds or shaking with the axle, it drives great. Just a leaky seal.


Now, on my 3rd seal and no leaks (few hundred miles over 2 weeks or so). I thought I finally got it fixed. I kept checking it every other day or so, and it was dry as can be. Then the other day, I noticed fluid under it on the passenger side, so I climbed under, and the seal is leaking again.


When driving, it was slinging the fluid everywhere, so I wipe everything down and searched all around. It looks like the axle seal again. It does smell like differential fluid, so I believe that I have eliminated any other sources. I let the truck sit a few days. When I returned, there were drops, dripping from the bottom of the axle housing, where it meets the CV axle. It was not wet anywhere else above the axle. I check the brake and power steering reservoirs, and they were full. I looked at the engine and nothing looks wet. Again, I can’t see anything else that is leaking, so it has to be the axle seal leaking.


I just put in an order for another new seal from the dealership and I am going to replace it again.


My question is...does anyone have any tips for getting the seal seated correctly? Or any ideas on why this would be leaking? I don't know what I am missing.


I did read on another thread that the bearing may be bad and causing it to leak. Could that be true? How would I know if the bearing is bad? I did not notice any play in the CV axle when moving it around, but it is still attached to the hub, so I don’t believe there would be much play.


When installing the seal, I did use a large bearing driver (around 2”) for seating the outer edge of the seal, tapping the bearing driver with a hammer. I had found online, that I should not drive in the seal too far, because there is no seat. They said OEM spec was 5.5mm from the edge. I tried to do that to the best of my ability. The seal looked very even all the way around and measured right around 5.5mm.


Any suggestions would be great.
Thanks in advance.

 

Just to be clear, you're talking about the seal inside the front differential? I just replaced both CV axles. I did the driver side seal correctly because it's almost impossible to screw up but I didn't do the passenger side correctly. Mine is just a slow weep though. It's not even leaking enough to hit my skid plate. I'm leaving it alone as I have no idea how to do it correctly if I were to attempt it again.

My advice, since you've tried it 3 times now, would be to just have the dealership do it. I wish I were more help. I know another person on here made the same mistake as you and I, so you're not alone.

 

Yes, the outer seal in the axle tube that is connected to the differential. The CV axle slides into this seal in the tube connected to the differential. We are talking about the same seal. part # 90311-47013

I agree, it seems easy, but I was just was looking for any tips that may have helped others to figure this leak out.

I know I found online someone that said there is no seat to stop the seal when putting it in. I personally believe mine has a seat, but then I thought I may have driven that one in too far. So the last one, I tried to keep at 5.5mm from the outside edge. It still ended up leaking after a few hundred miles. It just does not make sense to me. It really should be easier than this.

 

CV Axles are new OEM?

 

No. I am using Carquest (Advance Auto) brand CV Axles. But, I did replace the CV axle twice (OEM, Carquest, Carquest), just in case, the first replacement was causing the seal to wear incorrectly or leak. As I stated above, the first leaked before I even drove it, but I figured out that I had the seal installed in the wrong direction. The second did not leak immediately, but it did on the first test drive. The third leaked after about 100 miles of driving (2nd CV Axle). That is where I am today. I can't see 2 different axles causing it to leak.

I am beginning to worry that the angles with the leveling lift and larger tires may be causing it to wear incorrectly and leak. I see tons of pictures online with Tundras with lifts and I don't see tons of posts with this issue. Everyone can't be dealing with axle angle issues causing the fluid to leak. If that is the reason, I don't know what to do about that. My plan is to try and replace the seal one more time and see what happens.

Can anyone confirm that I am installing the seal in the correct direction? As mentioned above, the OEM seal has a rubber-coated side and metal side. I am placing the rubber-coated side out. The picture I have added is not mine, but I found it online. This picture shows the coated facing out (it also does not look like it has been tapped in yet).

Is this the correct direction to install it? I just want to rule that out.

Again, any help is greatly appreciated.

 

@FrenchToasty

 

@jbar322 That actually looks like the driver side. Isn't that the needle bearing we're seeing in the blurry pic? I thought you were originally saying the passenger side seal was leaking. When I did the driver side seal it didn't seem possible to drive it in too far. There is an obvious ledge it rests up against. As long as you drive it in in flush you should be fine. The passenger size was a lot easier to screw up because there is nothing to stop us from driving the seal in too far, which is what I beleive I did. I can't see how the brand of CV axle should matter.

Here is what mine looked like after removing that seal.


Here is once I installed the new seal.

 

Yes, I am talking about the passenger side. I only found that picture online to show the rubber coating on the outside of the seal, versus the metal on the outside. Your picture confirms I am putting it in the correct way. It looks as if you have the outside of the seal, equal to the first step/edge/bevel, whatever you want to call it. I might be slightly deeper than that edge (1-2mm). I remember I could fully see my edge. In the picture, yours looks like it is even to the edge. I will try to put it right on the edge this time. I can only assume yours did not leak.

 

Just to be clear, those are pictures from the driver side, which has the ledge you can't drive the seal past. As I mentioned yesterday, my passenger side is leaking but it's so minor it's not even reaching the skid plate below. I'm leaving it alone for now. You, me, and @FrenchToasty all seemed to have made the same mistake on the passenger side in that we likely drove the seal too far. I don't know what other advice I can give other than what I said yesterday. If you've not gotten it in 3 attempts I'm not sure I would try it a 4th time.

 

I don’t have my fsm in front of me, but it shows the depth to drive those seals in. Yes I believe the rubber side goes out like Erik said, and also that it can be driven in to hair to far.
One thing I knew but forgot to do, was lube the new seal, so it’s not dry when it starts to have friction it won’t ruin the seal while spinning. Also see where the seal rides on the cv shaft itself, make sure it’s smooth and not pitted.

 

Is this it?

edit-better screenshot,

 

I think it might be, I was thinking of the picture where it kinda shows which face to be measuring off of. Where it actually shows the pass side tube/bearing

 

I can't seem to find that but I'm terrible at navigating the FSM. I always search the wrong thing and Toyota will call it something different.

 

I have it printed out in binders at home in my “office”

 

Did you send it or should I look for a better picture explination

 

To bad, for others that need pictures to help understand. So if I’m reading it correctly it can be a minimum of .3mm past the very outside edge of the lip, and a max depth of 5.5m. So send it to 3mm deep past the very edge and call it a day?

 

That means 5.5mm give or take .3mm, so anywhere between 5.2-5.8mm would be in spec.

 

You and @Festerw are why I come here. Haha it’s all how you read it! Thank you for the clarification.

 

I’m having a Flat Earth Society Panic Attack on this one. You know those friends that convince you for a brief second that the Earth is Flat and your entire wurrld perspective gets rocked.

 

Sounds like you have a good launching point for attempt #4.

Two things to consider as well: 1) Frenchy made the point of ensuring that the part of the seal that touches the axle needs examined. If the reman axle you are using is pitted than oil can creep by easily. 2) Make sure your diff breather is not clogged at all. The passenger side seal you're replacing is the weak link, so it would naturally be the first place to leak if that were the case.

Be sure to follow up!

PS - How are the Eibachs?

 

Thank you all for your help. It is greatly appreciated. Installed a new seal last night. I hope this one works.

 

Where did you get a FSM for your Tundra? That is what I am looking for, 2018 Tundra

 

I found it on this site in the general info dump, maybe look in the 3rd gen section for a general info area and I bet somewhere someone had the FSM in a link.

 

I searched a few times but will keep on trying, thanks

 

My pass seal is leaking also so when I replace the steering rack, I'm, going to tackle that.

Is the part I circled in blue the seal, or the tool? Is the seal supposed to be 5.5mm deeper than the lip of the diff?

 

Blue is the service tool, a 2” pvc cap or coupling works well. And yes it’s supposed to be 5.5 deep past that lip

 

Did the 4th seal install fox the issue I’m having the same issue on my passenger side I’m in my second attempt

 

The info is for a first Gen. Most likely different for your truck