The Mitsubishi Pajero Owners Club®

[Levans]

What started as just a quick rear caliper swap has escalated as I've found more and more other bits worth replacing while I'm at it. One of those is the backing plate, as pictured here:
https://www.milneroffroad.com/mitsubishi-shogun-5-door-2.8-diesel-from-1993-to-2000-v46s/product/rear-braking-components-bsrr-br/brake-backing-plate-rear-l-h-003512/003512


To get at it, I presume I need to remove the hub assembly:

https://www.dropbox.com/s/fr9qy5jkj6h6he2/Photo%2013-12-2021%2C%2014%2045%2020.jpg?dl=0

If so, am I right in thinking that the circular metal part in the centre of the hub is some kind of removable cap, and behind it will be a massive nut with a huge amount of torque on it?

[Google]

[robfinger]

No cap to remove actually, no nut behind it. These are your standard Japanese semi-float axles, and what you're looking at there is the axle shaft itself - if you undo the 4 bolts that holds the backing plate to the axle housing the shaft will come out (with the bearing housing attached) allowing you to replace the backing plate. It's a very reliable and quite strong setup actually, but a bit of a mother to work on. The nut you're thinking of is what you'd find in a newer Shogun, the one with the independent read suspension, you ain't got that.

There are a few good videos on YouTube showing how to replace rear bearings on L200 trucks, this is the same thing here.

[Levans]

[robfinger]

Yeah don't mess with the bearing as it sits pressed onto the axle shaft, just yank the whole works off the axle housing as one assembly. Then switch the backing plates and toss the shaft rug bearing and it's retainer back in.

Food for thought here - from what I've seen online those are sealed bearings, is that correct? Cause in the US everything inside a solid rear axle is wet, the differential oil lubricates the wheel bearing too. The closest US axle to the Pajero/ Shogun/ L200 axle is the Ford 9", and the wheel bearings of those will last hundreds of thousands of miles. Why did the Japanese decide to not follow the same design principles, and instead separated the wheel bearings from the diff oil? Can't really see anything that can be gained by that.

[Levans]

I'll have a go at it tomorrow then if I can just pull the whole lot out as one unit and leave the bearings alone.

Yeah from the L200 videos I've watched it looks like the axle is wet but the bearings aren't. Not sure why if it works so well on the Fords you've got experience with.

You'd also think Mitsubishi would just make something like the backing plate/dust shield in 2 parts so it could be removed and replaced without having to go through all this. I've seen them on other vehicles where you can just undo a few bolts at the rear of the hub assembly, slide the old one off and slide the new one on. About a 5 minute job.

[drew m]

Hi,
Some people cut the shield in half and replace it that way, the bolts will hold it in place and either weld or seal where it joins I've went for years with no back plate after they've rotted of various 4x4 vehicle's with no problems and passed mot also (not even an advisory).
Drew

[radiomike]

[drew m]

Hi,
Just thought it might be an option all vehicles are different and need different levels of dismantling to replace plate so cutting shield may be an easier option on some vehicles,, it's normally the outer part of the plate that rots which is the case with my mk3 so they are missing (central part of plate still intact so hand brake still ok) I realise mk 2 is drum brakes, 5 minutes will cut shield with an angle grinder and a 1 mm disc some Shields for vehicles actually come in 2 half's for easy installation, other things to consider is damage to bearings and seals when pulling shafts..as long as missing Shields are not affecting braking it will pass mot.
Drew

[Levans]

I got the hub and axle off. I really hope I'm missing something here, but there doesn't seem to be any way to remove the back plate without first removing the wheel bearing.

https://www.dropbox.com/s/ob0perovd4bh8sd/Photo%2019-12-2021%2C%2018%2024%2033.jpg?dl=0
https://www.dropbox.com/s/4wtqj1sdynirf9u/Photo%2019-12-2021%2C%2018%2050%2040.jpg?dl=0
https://www.dropbox.com/s/w1zh0izawaqpz2i/Photo%2019-12-2021%2C%2018%2050%2055.jpg?dl=0

As can be seen above, it's sandwiched between that back plate on the axle side (with the studs sticking out of it) and the hub assembly at the front. Or does the back plate somehow come off without needing to touch any bearings?

[robfinger]

Well, fawk, that clearly ain't how I recall mine being last time I was in there. Ffs, yeah that thing ain't coming out in one piece without the bearing carrier being pressed out. I actually just downloaded the factory service manual, and in the rear axle section it says nothing about how to replace the backing plates, but from what I'm seeing in your picture even if you're cutting it into pieces those 4 studs that hold the bearing carrier (Mitsu calls it a bearing case) need to be pressed out cause they go thru the plate.

No easy way out of this situation it seems. So much for Japanese designs being the end-all-be-all (as great many across the Atlantic seem to think). My plan of attack here would be to press/push the 4 studs out, cut the old plate in half and remove it, cut the new plate in half and install it, and weld the new plate back together. Actually tbh I'd just replace the wheel bearings.but that calls for a press that can do 10 tons of force comfortably.

[Levans]

I'll just have to leave it as it is then and hope it doesn't cause me any problems (or fail an MOT). I was thinking even if I tapped the studs out, how would I get the replacements back in? There's no room between the hub and the back plate to get a hammer in there.

Do you know if there needs to be any liquid gasket applied to the face of that plate with the 4 studs sticking out of it? There's a very thin rubber O-ring around the circular part but that seems to be it. I was expecting an actual gasket of some sort, or the residue from some kind of sealing compound, but there didn't seem to be either.

[robfinger]

Yes there should be some sealant on the surface between the bearing carrier and the axle housing flange it .ates to. Manual calls for 3M #8663 or equivalent - go to your local NPA store and ask for black "instant gasket RTV silicone", it comes in a tube you put in your standard caulking gun and costs about $5, that should do you fine for this job. Don't put too much of it on there it's not a case of "the bigger the blob the better the job" 😂

How does your wheel bearing feel btw?

[Levans]

Thanks, I'll make sure I use some then.

The wheel bearing actually feels very good. There's no play in it and it rotates nice and smoothly, so it'd be a shame to cut it off and replace it anyway. My biggest concern with leaving the backing plate is that it'll continue to disintegrate to the point that it can no longer support the handbrake mechanism, but maybe if I clean it up and slather it in rust converter, I can at least delay that for a while. What a poor design though. Anything likely to corrode that much really ought to be something that just quickly bolts on.

[robfinger]

I agree it's a dumb design. Admittedly there are worse out there (I'm looking at you GM) but still.

Good on the wheel bearing! You running standard wheels and tires, or something oversized?

Rust conversation might not be a terrible idea. Give it a shot.

[drew m]

Hi,
I used aquasteel rust converter for a while which was pretty good recently been using owatrol followed by a couple of coats of u-pol gravitex, owatrol not cheap but goes a long way you can get a 100ml sample for 6 nuggets which would be enough for your needs.
Drew