Replacing a front wheel bearing.

[P38 4.6 Timmy]

G'day all.

A few weeks ago I discovered I had a bit of play in the driver's side front wheel bearing. Due to the fact the wheel bearings on our trusty steeds are the non-serviceable, non-adjustable, (non-4wd worthy!) pressed in type, I figured I'd best replace the bearing unit before the wheel falls off

The write up on RR.net is pretty good, but a couple of details are a bit sketchy so I thought I'd share some points and pics.

The genuine Timken item is not carried in Oz (I rang their head office) the part no. is correct, (NP275832-90UA1) but it would have to come ex France!
I found a part no. for a SKF replacement, but after contacting CBC, Statewide Bearings and 1 other local supplier, I had absolutely no joy

Most of the U.K. LR suppliers carry the genuine Timken kit, which contains the bearing unit, the snap ring, the axle shaft oil seal and a new stake nut...AND, it's a couple of pounds cheaper than the same Timken bearing unit just by itself..go figure..

By the way, Britpart offer a much cheaper "aftermarket" unit, but there's no way I'm fitting some questionable quality item, which is made who knows where, in a spot as important as a wheel hub!

I ordered the kit from Paddock, and it was about $215 landed. I'm going to do all 4 hubs, but funds are a tad tight right now, so it's the squeaky wheel that gets the oil...sorry, I couldn't resist

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The hub removal is all straight forward and is covered in the RR.net write up, so I won't bore you all with that! Plus I'd had this hub off several months ago to replace a broken axle half shaft (aka: The Weakest Link) so it all came apart nice and easy.

Next post, I'll get to the fun part - pressing the hub apart and pressing the bearing unit out of the hub.

[P38 4.6 Timmy]

I apologise for doing this 1 post 1 pic thing, but I can't upload more than 1 or 2 pics per post without it all having a meltdown and giving me the "Upload failed" message.

Plus the power just went out here, so I'm using my phone as a hotspot for my iPad. It's been a 42 degree day as well, it's 7.20 pm and still 36. Hope Western Power sort it soon, the house is warming up with the a/c dead!

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[P38 4.6 Timmy]

Oh, I forgot to say..even though there was only a little bit of noticeable play in the bearings with the wheel jacked up, when I had the hub off and gave it a spin, it sounded terrible, dry, notchy and rumbling, just goes to show, not easy to tell their condition when the hub is together and the road wheels are on.
It felt and sounded ok several months ago when I replaced that half shaft too, but was probably on it's last legs, and all the mud plugging and deep water fun I had during the winter must've been the death warrant!

The previous pic shows the hub pressed apart, check out the state of the "grease" in there..nasty aye.

My 20 ton press just managed to separate the hub. I applied some heat to the outside with a turbo torch at the same time as applying force with the press, then it came apart with a big BANG (don't forget safety specs).

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I also forgot to snap a pic with the hub set up on the press before I separated it, but it's straight forward. You need to space the bed plates up off the bed to give clearance for the hub flange and wheel studs. Then a 32mm socket fits nicely on top of the stub shaft, and presto, Bob's your Dad's brother.

[P38 4.6 Timmy]

Now we are left with an inner ring (race) and it's set of rollers with cage, stuck on the stub shaft, while the outer rings/bearing unit sleeve (the outer sleeve and rings are all one piece, machined from a single piece of hardened steel, unlike the inner rings, which are seperate) are stuck inside the bearing carrier section of the hub.

I find a lot of people misuse or misunderstand bearing terminology like race, inner, outer etc, so I'll pop in a little diagram for reference.

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This is a ball bearing obviously, but the terminology applies to roller bearings also. Oh, and the term "race" actually refers to the contact surface of the ring where the ball or roller runs.

[P38 4.6 Timmy]

Before pressing the bearing unit out of the carrier section of the hub, there is a snap ring which must be removed.

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Then it can be pressed out. This came out without the need for heat, but I reckon it almost had the full 20 ton force on it!

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[P38 4.6 Timmy]

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You can see all the pitting in the outer rings here.

Removing the inner ring from the stub shaft requires cutting a groove in it, 90% of the way through, then giving it a good whack with a cold chisel which will split it, then wedge a screwdriver in the split and it will tap off quite easily.

The power is still out here...not happy Jan!
I'll ad some more tomorrow. Cheers, Timmy.

[P38 4.6 Timmy]

2016-02-09 11.00.22.jpg
This pic shows removal of the inner ring as described in the previous post.

Hey Kiethy, if you're not careful, you'll run out of "Thank you's" mate..

[Keithy P38]

Thanks ;-)

[P38 4.6 Timmy]

This pic shows where a small piece of a roller broke away, the piece was lodged in the adjacent seal. This is the inner bearing (the one closest to the diff).

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[P38 4.6 Timmy]

This shows a nasty section of spalling on the inner ring of the outer bearing (farthest from the diff).

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