Rear diff oil seal?

[Sampraz]

Hi all,

Yesterday I was checking my brakes ahead of MOT (now postponed for a second time as I keep running into more problems!) and noticed that the rear offside wheel wasn't braking as strong as the nearside. When I removed the drum the linings and drum were plastered in a thick oily substance. Also, there seemed to be metal filings mixed through it which has got me quite worried! 8O

I checked the wheel cylinder for leaks by clamping the pistons and applying pressure on the brake pedal but it doesn't look like this is the source of the leaking fluid.

From reading other posts on here it looks like it may be the oil or grease seals in the rear axle / bearing which is causing this. Would I need to change both seals or would the inner oil seal typically be enough? I'm a bit worried by the thoughts of having to change the outer seal as it looks like I would need to remove the bearings etc and would be quite a difficult job without the right tools (axle shaft remover, bearing press etc).

Also, any ideas on where the filings could have come from? There is no noticeable noise from the bearings when the wheel is rotating so not convinced that it is from the bearing breaking up? Could the filings make it through the seals / bearings from the diff, or is there a metal ring etc in the oil seal itself which could be breaking up?

 

[rustic]

A few years ago my offside rear wheel/tyre had gear oil running down the inside.
The garage replaced the outer seal and then a few weeks later same thing again, it turned out it was the wheel bearing after all.
A new bearing and seal and all was ok.
This was in the days when I didn't do the repairs myself and it cost I think in the order of £200
You may need a special tool to remove the hub and also a special tool to remove the bearing.
I guess someone will be a long shortly to answer that one.
Best of luck,
best regards,
Rustic

 

[Sampraz]

Hi rustic, thanks for the reply.

Looks like it might be quite costly then if I have to replace the bearing as well. Can anyone offer any hints / tips on doing this DIY style, or is it a job best left to a garage? I've replaced bearings on cars before, but never worked on anything as big as a 4x4 or anything with rear wheel drive so am a bit hesitant on starting into this.

I haven't had a chance yet to remove the axle but might try and get a look at it tomorrow evening. Hopefully I might be able to see if there's anything wrong with the bearing once I have the axle out.

 

[ronypony]

Can I offer some encouragement with your problems. Do not be put off doing the job yourself..its not particularly difficult.The fact that the vehicle is a 4x4 makes doing this job easier not more difficult...the components are larger and in many ways more managable than the smaller components of a car.
I had the same problem you describe with a Daihatsu Fourtrack...different vehicle...same problem.
You will save a lot of money doing the job yourself and have a much greater sense of satisfaction maintaining your own vehicle.

There is a work shop download that deals with replacing the outer seal on the half shaft...with some helpful photos and suggestions. (downloads section of this site)

When I did the Fourtrack I replaced both the inner and outer seals...the inner seal was held in place by a retainer ring which had to be ground off the half shaft to remove the seal. The bearing had to be pressed onto the shaft and I had a small engineering place do it for me for a few quid.

In order to remove the half shaft I made my own 'puller' to get the shaft out...in the workshop download there is a suggestion about using a loop of rope and sledge hammer...clever idea..heres some pics of the puller I made..

The puller was bolted to the wheel studs and the small sledge hammer head was used to knock the half shaft out..easy

I think if your going to the trouble of stripping down the drum brake and getting the half shaft out , it makes sense to do both inner and outer seals....the fact your brake linings are oil fouled suggests to me that both seals are shot....I replaced the bearings at the same time...

Honestly if you don't mind getting your hands dirty and enjoy a bit of motor maintainance...DIY :smile:

p.s. just thought...the Foutrack inner seal did have a metal ring for seating the seal if I remeber correctly...so you could be right about this being the source of the metal filings...doubt very much they will be diff related...or bearing if as you say the bearing is quiet when wheel is rotated...if a bearing has broken up you hear it...

 

[Sampraz]

Hi ronypony,

Many thanks for the words of encouragement :smile:

I think you are right in that while I have the halfshaft out I may as well replace both of the seals. Also, I assume I would need to remove the bearing to get at the outer seal anyway so pobably better off replacing it for a new one too. Bit more costly now, but could save a whole host of problems later.

It will probably be a few days now before I get a chance to get back out to remove the shaft, as I am going away for the weekend, but will certainly let you know how I get on.

Many thanks again....

 

[ronypony]

Your welcome...

Your assumption is correct ...to get to inner seal necessitates removing the bearing...I think the inner seal must be leaking otherwise the brake linings would not be fouled...it means axle oil is getting into the drum.

Replacing both seals and bearing will cost a few quid...but not nearly as much as giving your vehicle to a garage to sort out.

Best of luck if you do go for it yourself...be interested to hear how you get on.

 

[Sampraz]

Well, I was able to grab about half an hour this afternoon at the T2 and managed to get the halfshaft out OK. Looks like the inner oil seal (it's the one seated in the axle tube rather than in the bearing carrier) has definitely had it.

To reduce future problems though, I also intend to replace the bearing and the grease seal while I'm at it. I didn't have much time left but did make a start on trying to get the shaft out of the bearing. I managed to remove the lock washer and nut, but getting the shaft out seems to be a lot more difficult!

From the workshop manual it looks like there is a special tool to remove the shaft, but it isn't quite clear how it works. I am guessing that it bolts onto the four bolts on the back of the hub and presses the shaft outwards (towards the hub / studs) through the bearing.

I am thinking of perhaps removing a couple of the studs on the back of the hub and using long bolts to try and force the shaft out, but not sure if this will work.

Unfortunately I ran out of time (had to collect kids from friend's house) before I could make much progress with this, but am just wondering if anyone has any tips for removing the shaft from the bearing without the special tool.

 

[Toolbox]

The oil seal that is the problem is the one in the axle tube allowing oil through, the seal nearest to the wheel behind the bearing is only to retain the grease and stop dust and dirt entering the bearing.
If the bearing is ok and there is no play or noise when assembled, then I would not disturb the rest of it just repack with grease and change the offending seal in the axle.

 

[ronypony]

Now that you have the shaft out inspect seals carefully to ascertain any damage.
You could be fortunate and find its only the axle shaft seal....If it were only the back of the battle plate that was oil fouled I would say that was the case.
What would concern me is why the brake linings have been fouled...how is the grease/oil getting into the drum ?...it must be getting past the bearing seal somehow.

 

[Sampraz]

Thanks for the replies Toolbox and Ronypony.

Unfortunately I can't see the grease seal on the outside of the hub as I would need to remove the shaft before it would be visible, so can't tell what condition it is in at the mo.

I must admit, I am kind of tempted just to replace the oil seal and leave the existing bearing in place. Thing is that I've already bought a replacement bearing so if I can get the shaft out without too much hassle, I figure I may as well change it while I'm at it.

The main reason I got the new bearing was the fact that there seemed to be iron filings mixed through the grease / oil in the brake drum, so I was a bit worried that the bearing may now be contaminated with the metal debris and could cause problems in the future.

Will give it another go anyway and see how I get on. If it doesn't work out, I might just put it back in the way it is (and keep the new bearing for future repairs if necesary), or else see if I can find an engineering shop that could press the shaft / bearing for me.

 

[Sampraz]

While trying to find out a bit more info on how the shaft is removed from the bearing, I came across this video: http://www.youtube.com/watch?v=vAcSbs74AFQ

At least now I know how it should be done with the proper equipment. All I need to do now is figure out a way of doing it DIY style :smile:

 

[ronypony]

Its going to be difficult without a press m8...why not take your half shaft along to any local friendly small garage....most will have a press...I am sure that you could get the old bearing pressed out and a new one pressed in for a couple of quid...with a press it takes seconds as that youtube video illustrated...

when I had mine done the small engineering place I took it to charged me a tenner...

 

[Sampraz]

Quick update on this.

I finally managed to grab an hour or two this afternoon, with help from my uncle, and we successfully replaced the rear wheel bearing and outer grease seal. :smile:

Haven't yet fitted the halfshaft / hub back on the vehicle but will hopefully get that finished off tomorrow, along with the inner oil seal in the axle tube.

I managed to avoid the need for use of a press by using the approach I suggested above - i.e. I removed two of the studs used for attaching the hub to the axle tube, put two long bolts through these holes (with nuts placed against outer edge of battle plate) and gradually tightened the bolts in to apply outward pressure against the axle shaft / wheel plate. After a few minutes alternating between the bolts, the shaft popped out.

I was then able to drive the outer bearing case out of the hub using a large 3/4 inch drive socket and hammer. New bearing was tapped into place using the old outer bearing case as a guide.

Thanks to everyone who offered advice / tips etc on this thread.

Cheers.....

 

[ronypony]

Nice one :smile:

Nothing like a bit of DIY to make you feel good :lol: