Rear Hub Axle Oil Seals

[stuzbot]

Righty oh. Finally having vanquished the ABS Sensor From Hell [coming to a cinema near you], I've finally pulled my rear stub axle and got to have a look at the seals. So, what do those of you who've "been there— done that" think of these?

To my untrained eye, the inner oil seal looks fine. There's no obvious deformation or tears to the rubber...

...which is more than I can say for the outer seal. As you can see from the photos, the ridged seam around its centre is running at an angle and looks "rippled" in places. I'm assuming it's not meant to look like that...

Of course, as I've mentioned before, the truck came with a spare inner oil seal when I bought it and so it looked like previous owner intended to replace that. Before starting to tear things down and, in spite of my natural pessimism, I had hoped the dampness round the rear hub might be a leaking wheel cylinder [easy job] but expected it to turn out to be that inner oil seal [medium job]. But it's now looking like it's an outer oil seal [arse of a job].

When taking the nuts off the back of the hub assembly, I found that one of them was pretty rough turning, like it had been cross-threaded before. Also, on that side of the wagon, the brake backing plate has been replaced with a new one. So I'm starting to think that someone took it apart to fit the new backing plate and somehow knackered the outer oil seal, while sticking things back together again. And either they or someone else has seen the leak, bought an inner oil seal to fix it and then done what I've just done; pulled things apart, realised it's the outer oil seal and decided to give up, at that point.

So what think you all?

BTW I do have a hydraulic press. So "in theory" should be able to press the bearing etc off the axle. But "in theory" the ABS Sensor just lifts out after you undo the bolt. So I'm not even going there yet.

 

[felix2566]

Personally while you have it all apart and you have a replacement seal I'd 100% change it. Lip seals can look perfectly ok and still be leaking. Assuming the inner seal isnt that hard to change, doesnt look like it should be.

 

[stuzbot]

Personally while you have it all apart and you have a replacement seal I'd 100% change it.

Yeah. I did think exactly the same. But then I followed it up by musing on the old "If it ain't broke..." adage. I'm pretty sure it's the outer seal that's the culprit. But it could be the inner... or both.

 

[stuzbot]

Well, it looks like I may have been barking up the wrong tree. According to Roughtrax, the outer seal isn't an oil seal at all, but a dust seal...

...and doesn't play any part in keeping oil from oozing into the brake drum...

This is actually good news as it means that [hopefully!] it's just the [also hopefully] much easier inner oil seal that needs replacing. So I shouldn't need to dismantle the hub assembly any further.

 

[BobMurphy]

I would replace the inner seal "while you're in there" - if only for peace of mind !

Bob.

 

[MikeJak]

I'd replace the inner seal as you're there... true, the outer is only a dust shield as far as I know. have you checked that the breather is free and not clogged? it's quite a common cause for the axle building pressure and pushing oil through the seal

 

[stuzbot]

...have you checked that the breather is free and not clogged? it's quite a common cause for the axle building pressure and pushing oil through the seal...

Yes. I replaced the breather last year, hoping it might cure the problem. But since the hub and brakes were already oily, it's hard to tell if this stopped any further leakage. Hence why I'm doing the seal too.

 

[Aeroelastic]

Hi Stuzbot, not sure where you are at this job. Just watched a youtube video from The Car Care Nuts (which some of you would know I supposed as his Toyota knowledge is second to none):

Part of the video is for the inner seal replacement. He didn't remove the abs sensor. If you are doing both sides of your axle seals, might be worth considering leaving the sensor in place but be careful. To save you some hassle.

For other 80s owners, Some of his videos about the 80 series are really details and full of information. But he only focuses on petrol engine as that's what they have in the states.

 

[stuzbot]

I'm just waiting for an oil seal puller to arrive, as I want to try and pull the old seal without wrecking it too much, so I can see what kind of a state it was in. So everything's on hold til the weekend. But the stub axle is out and the ABS Sensor did surrender eventually.

Cheers for the video link. I've not checked out that channel before.

 

[stuzbot]

Back to this again... after the usual hiatus of life getting in the way, Royal Mail kidnapping my oil seal puller coz of excess postage to pay and the onset of a mini monsoon season [which seems to follow me wherever I go].

Anyway, in the thumb-twiddling interim, I came across the following blog article from someone doing the whole outer and inner seals plus bearing job [needless to say, with a special tool he's also promoting].

Replacing My Rear Axle Seals & Bearings on a Toyota 4Runner (also Tacoma) | AdventureTaco

Well, as I mentioned previously, our last family camping trip was both a success and a failure. I mean, the camping part was all success, but noticing that my rear axle seals were leaking when we got

adventuretaco.com

One thing that did set alarm bells ringing though was when he said:

Having that done meant that I could test the position of my inner retainer on the axle, so I drew some lines with a marker and inserted the axle into the housing. A few turns to get the seal to rub off some of the marker, and I knew I had a problem. I'd pushed the retainer on 5mm, but it was too far. It was back into the shop where I used the Rear Wheel Axle Tone Ring Puller (have I mentioned that this thing is awesome?) to quickly pull the retainer and tone ring 2mm up the axle. And the next test fit was perfect!

Here's the pic he possts with his "I'd pushed the retainer on too far" comment...

and then when he pulls the retainer off again and repositions it...

and here's the stub axle I took off my truck...

He mentions in the article that there should be between 3-5mm of the shiny part of the axle showing, when the retainer is pressed on by the correct amount and that he did 5mm first and it was too much. But mine has about 10mm [if not more] of shiny bit showing.

So, given that the stub axle I took off has had the brake backing plate replaced at some stage, I'm starting to get the sinking feeling now that someone has taken the axle out to do that job and then, when sticking everything back together again, has just twatted the retainer down as far as it will go so that it's not riding on the oil seal where it should and hence the leak. That would also explain why the oil seal looked good when I took the stub axle out [although, as others have said, it could look good but still be leaking].

So now, before I start pulling the oil seal, I think I'll try the marker pen on the retaining ring trick and see if my worst fears are realised. Oh dear. I think I can see rabbit holes opening up in front of me on yet another "couple of hours job".

 

[stuzbot]

Well, unfortunately it seems like my theory is correct:

I marked up the inner retaining ring, refitted the axle stub and gave it a good spin. When I took it back out, none of the marker lines were touched at all [Sorry. They don't show up very well in the photo]:

Hmmm... time for a few calculations. I first measured the depth the oil seal is inset within the axle housing:

It's inset by 40mm. But there's a lip around the housing which sits inside the faceplate on the stub axle [where the big rubber O-ring seals]. That lip is 8mm high. So, when the hub axle is assembled the outer face of the oil seal will be 40 - 8 = 32mm inside the hub & axle assembly.

Next up, I measured the distance on the hub axle itself, between the faceplate which bolts to the axle housing and the inner face of the retainer. I wasn't able to do this with fraction of a mm precision as they're on different levels. But I used an engineer's square held as best I could at a right angle against the axle and measured between that and the faceplate. So I think I got reasonably accurate. I couldn't hold the square, the micrometer and my phone to take the pic all at the same time, as I've still not evolved a 3rd arm. But you get the idea:

I measured that gap at 32mm which, by amazing coincidence is the same result as we got from our calculation above. So, in other words, instead of the retainer riding inside the oil seal, the inner face of the retainer is just about butting up against the outer face of the oil seal. No wonder the fecker was leaking!

Well, to say that is a pisser is a massive understatement. But kind of par for the course for my history of attacking relatively simple jobs and them turning into a complete ball-ache. Whoever changed the backing plate on this axle before has [either by accident or design] pushed the retainer—and ABS tone ring—down way too far onto the axle so it's not making any kind of a seal at all. I'm just amazed it leaked as little as it did. and, when I checked the diff oil level last winter, it was OK.

On the plus side, I didn't waste even more time replacing the oil seal, which may be good after all and which wouldn't have fixed the problem anyway. On the minus side, I'm now faced with the ordeal of cmpletely dismantling the axle which means more time and probably more money, if I have to try and find a UK version of the special tool that guy was promoting in the article I linked to above.

I did see a bloke on Youtube changing the wheel bearing without any special tools. His "technique", for want of a better word, involved repeatedly twatting the stub axle onto a piece of wood on the floor til he forced the retainers off. And while that appeals to my budget and skill level, it seems a bit too "Neanderthal", even for me.

EDIT. Here it is:

 

[MODVRS]

I feel your pain! There is a good "Timmy the tool man" Youtube video on these too where he goes into some detail about setting up the retaining ring etc. He had a special tool for using in a press to get all the bits off and back together afterwards.

Probably has no relevance but I saw in my car's history file that it had an official Toyota recall for rear axle shafts in 2007 and the work was done at no cost.

 

[felix2566]

Yes it's a pain in the butt, but great you found the real cause for the leak and can fix it properly this time. Imagine the frustration after fitting a new seal and it's still pissing oil....

 

[stuzbot]

Well, it seems like similar tools for doing this job are available in the UK too. And on Amazon no less. So, maybe I can solve this problem by throwing even more money at it.

https://www.amazon.co.uk/s?k=toyota+hilux+Rear+Axle+Bearing+%26Tone+Ring+tool

Actually, I'm thinking that, if I did buy one of these tools—and it did actually work—I could partially justify the expense by rebuilding both rear axles and replacing the brake backing plate on the other side while I'm at it, as it's really crusty. I did wonder why a previous owner had replaced one and not the other. Now I know why.

EDIT: Arrrgh!—all those tools in the Amazon search results are shipped from America. So they'll take forever to get here... and probably have customs charges to pay too.

 

[BobMurphy]

Oh dear, I had forgotten that little 'got you' ! Been there done that and in my case I stretched the inner seal retainer so it was loose on the shaft - another order to Toyota!
I had to build & strip the half shafts a few times before getting the retainer and ABS rings in the right place.
The ABS ring should line up with the hole where the ABS sensor goes, which is a useful cross-check before re-assembling the brakes.
Every day a School day !

Bob.

 

[stuzbot]

Every day a School day !

Indeed. Although, in this case, it feels like I'm being given detention for someone else's messing about

 

[stuzbot]

Just a couple of quick additional thoughts on this:

1: I was pretty pissed off with all of this yesterday, as I'm going to visit a mate in Wales at the end of the month and i'd been hoping to get the Surf sorted by then and use that as its first road trip. I doubt that'll happen now, what with life, work and the inevitable crappy weather that's due to happen between now and then. So I'm just letting myself get back into the "this is my fun project vehicle that I work on when I feel like it" mindset and not get het up on trying to get things sorted by any specific deadline. Because that way it ends up becoming a chore and not a hobby.

2: In the blog article I linked to a few posts back, the guy mentions checking if your axle oil seal is leaking by pulling the ABS sensor and checking whether it's got oil on it. Now, this may have already been blindingly obvious to the rest of yous. But was a bit of a "Duh!" moment for me. Of course, this only works if you don't have to pour half a litre of penetrating oil in aound the ABS sensor first, to get the fecker out. But I think it's a handy tip for checking for oil seal leaks, without having to pull the axle out.

3: While wallowing in my misery last night, I came across another YouTube video with someone doing the tone ring / retainer removal with a home made tool. Reading the comments on that video, there were several where people said that they'd suffered exactly the same issue I've got here; ie. that they'd taken their truck to a garage [or "shop" as the yanks insist on calling it] which had pressed the tone ring and retainer on as far as it would go and left their axle leaking. So, just judging by that small sample it seems like it's a pretty common problem even for supposed "professionals".

It makes me wonder why Toyota, with their "easy-to-work-on" older trucks like this came up with a stub axle design which required a complete strip down, using some hefty and specialised tools, just to change a brake backing plate... which is almost a service item? And why they made the positioning of the. inner retainer, which needs to be pretty precise to avoid oil leaks, so abitrary that there's not even an etched line on the axle to show you where it sits, much less an actual stop to press it against?

Anyway, just my tuppence worth, before I go and do something less mechanically taxing with the rest of the weekend. The missus has been after me to put up a frame in the garden for her to grow a climbing rose up. At least that should be straightforward.

[Cut to footage of stuzbot, lying bleeding in a tangle of broken wood and rope, with a shovel stuck through his foot]

 

[stuzbot]

Back again to chew over this;

Having looked at those rear axle tools on Amazon and a few vids of people using them [why are they only available from Amazon US? I can't find them anywhere else] I don't think they're going to be any good to me—even if I ordered one, endured the wait til it got here and avoided Customs charges.

The trouble is that the C-shaped plate on them, that fits around the axle behind the ABS ring to pull that and the inner retainer off, are made of thick steel [looks about 6mm] which, of course, they need to be to take the forces involved in pulling the ABS ring and retainer off. They were obviously designed for removing properly positioned retainers and tone rings, not ones that had been twatted down as far as they will go, by some eejit, as has been done on mine, so there's barely 1 or 2mm clearance left between the backplate and the ABS ring. There's no way the C-plate from one of those tools would fit in there:

So that would seem to leave me only the option of carefully cutting the retainer and ABS ring off and fitting new ones. Roughtrax have the ABS ring at £37 but I can't find the retainer. Am I calling it the right thing? I called it the retainer coz that's what the yanks were calling it in their YouTube videos. Does it have a different name this side of the pond?

And, if I do end up having to go down this route, has anyone any tips for cutting the retainer off without knackering the axle?

I did also ponder on adding heat to the equation, by heating up the retainer to see if that would loosen it enough to hammer off. But I'm a bit loathe to do that as it's so close to the bearing. Mind you, intarwebs wisdom says the bearing will be on borrowed time too now, as the leaking axle oil will have flushed out the bearing grease.

EDIT: I found the retainers. Apparently they are called retainers after all. Didn't show up when I searched for "rear axle retainer" but did when I searched for "rear axle bearing kit"

 

[felix2566]

What about heating it up and seeing if it will drop off that way?

 

[stuzbot]

What about heating it up and seeing if it will drop off that way?

Ahem...

I did also ponder on adding heat to the equation, by heating up the retainer to see if that would loosen it enough to hammer off. But I'm a bit loathe to do that as it's so close to the bearing

I've not completely ruled it out though. Just a bit wary.