Fixing a Defender Steering Box Leak

[DeanoH]

There are only two places where a Defender steering box can leak and mine leaks from both of them.
They are the input shaft (from the steering wheel) and the output shaft (to the drop arm) which connects to the road wheels.

Accessing the steering box to replace the seals (if you can get them) is a bit fiddly as there's lots of things in the way.

What I found was that both the input and output shafts of the steering box were not leaking between the shaft and the seal but between the seal(s) and the steering box housing itself.

The input shaft is an unusual seal in that it is not your average press in seal that pushes into the housing with a seal on to the input shaft. It's sort of a backwards type seal that presses onto the shaft and seals by pressing onto a machined surface on the outside of the steering box.



This is the input seal from the outside (away from steering box side).



This is the same seal from the side that faces the steering box.


As you can see from the second photo the 'hole' in the centre of the seal is thorugh steel. This is pressed onto the shaft where it is pushed up to the steering box where the rubber/neoprene (whatever) washer presses onto a machined surface on the outside of the steering box to make a seal.
As the rubber wears or the metal to metal seal loses tension over the years the seal becomes ineffective and starts to leak.

I haven't seen this seal advertised individually but it is available in a steering box re-build kit. The only problem here is that removing the steering box to do a rebuild is a major (though relatively simple) exercise where all that may be needed is to have the seal exert a bit more pressure onto the steering box to re-create an effective seal.

This could be as simple as using a large screwdriver to carefully lever the seal closer to the steering box or if you're real keen, remove the steering shaft and unis and use a suitable socket to gently and evenly 'tap' the seal towards the steering box to place more tension on the seal. Very cost effective.
Of course I only figured this out once I removed the seal by levering it off the shaft and distorting the steel.

Could be a real simple quick and effective fix for a leaking input seal.

My local bearing service tells me that these 'STEFA' seals are not hard to get and has ordered me a couple. More info on this when they come in.


The output shaft seal is a bit different, sorry no pics in bits for this one. Here it is in situ.



Here's a close up showing the seal onto the shaft.



With mine steering fluid was (again) leaking not between the shaft and the seal but between the seal and the housing.

This was quite easily fixed by removing the seal and cleaning the seal/housing surface and applying a liberal amount of Stag Cement to the mating surface of the seal. This is the red/orange line you can see in the photo. No leaks and very cost effective. Again, I have not seen this seal listed individually but only as part of a rebuild kit. No sealing compound was on the seal I removed so it was just a 'friction' fit, rubber to steel. Don't know if this is the way it's supposed to be or just the way it was

So if your Defender is leaking steering fluid it may be a real cheap and effective fix, if you're lucky.


Deano

[eddy]

Timely information,my Discovery1 pas box is leaking from the input shaft seal.So you are saying I may get away with drifting[using some tubing] the seal further into the housing. Will give it a go!

[DeanoH]

Don't know if the Disco has the same system, but definitely worth a look.

Even using a suitable open ended spanner over the shaft and pressing on the seal may do the trick.
To drift the seal in evenly it is necessary (in the Defender) to remove the shaft between the two unis. To do this three pinch bolts need to be removed and the lower uni. It's a real good idea to park with the wheels straight ahead and mark the splines .

Power steering Stop Leak is also a very good proposition. Used it on my old Mazda T3000 bus and six years later when I sold it the steering box was still good.

Deano

PS. Just noticed where you're from. My old T3000 was an old Mandurah school bus.

[djam1]

I understood that the leaking is a symptom not the problem.
Just buy a new one and save yourself the grief

[uninformed]

I know bugger all about steering boxes, but have been told if its the top seal normally can get away with a rebuild kit. If its the bottom its a good chance its the shaft flogged out at the bearings as the shaft material is not great.

Im not saying this is the case with yours. I have just got my new OEM replacement box with pitman and hope to change it out this week.