How difficult to fit a bearing hub assembly?

[Pan Pan Pan]

280E said:

Pan Pan Pan said:

Changing a wheel bearing is fairly easy, but there are some points that need to be watched out for. Knocking out the old races is relatively straightforward, if the inside of the races has a shoulder, or a slot which allows a drift to be used to drive the old races out of the hub. You have to be careful not to score or dent the race flange, as even the tiniest of defects can stop the new races from being pressed home. The new race can be tapped home using a drift (suitable diameter socket for example) taking care to ensure they remain in alignment with the hub flanges. If I doubt take the hubs and races to a garage, and ask them to press in the new races with a hydraulic press.
When re assembling the hub bearing it is important not to overtighten the locking nut. Spin the hub whilst slowly tightening the nut until you can just feel the bearing start to bind, then slacken the locknut back off, just enough to allow the hub to spin freely, then set the splitpin, castellated hub locking cover. Make sure both the hub races, and bearings are completely covered in grease before assembly.

I think you can disregard all of this on the OP's car

ETA: Sorry, that sounded a bit pompous - PPP's advice is spot-on regarding taper roller bearings

Edited by 280E on Tuesday 31st January 22:02

No apology required, It just goes to show how long it has been since I have had to change any wheel bearings. Out of pure interest what type of hub bearings do BMW use if it is not a taper roller type?

[cbmotorsport]

Is it your only car?

I remember trying to do a job once on my daily, and it proved a nightmare. Everything corroded and stuck etc, I ended up needing heat which I didn't have, and by the time I'd exhausted all options, everywhere was shut to get a blow torch. Ended up having to get a lift into work the next day.

Point is, these things are never as simple as they seem. Good chance the garages are quoting on the worse case scenario.

[RobM77]

Have a look on You Tube - for me that's supplemented workshop manuals these days. I don't want to link to any particular video in case it turns out to be wrong though

My advice if you're a novice would be to ask a friend to help in exchange for a bottle of wine, or at the least let him know you're doing it and may need to phone for help. Note that working on your only means of transport at the weekend is a dodgy thing to do, because often with jobs you need a new part halfway through, and you've obviously got your only means of getting to the dealership to buy that part disabled, and you can bet it'll be Sunday at 3pm when you run into problems!

[SuperchargedVR6]

Same setup as the MK5 Golf (less the driveshaft) and simple to do. I would strongly recommend researching the hub bolt (part 7 in the second link) because the torque setting will vary if they changed the bolt head and shoulder type. The bolts are all probably "use once" torque to yield, so you'll need those too.

Also check if any of the bolts are the triple square type the Germans love so much, and get the appropriate sockets ready.

If it's a daily car and you're doing this on a weekend, you need to be pre-armed with all the right tools and parts or you could be left stranded if something breaks that you haven't got a replacement for.

[davebem]

By some strange coincidence Ive also just changed the front bearing on a Alfa159 and its the exact same design as the one in the BMW diagram. It was very straight forward, 4X torx bolts hold the entire bearing assembly on, and you need to undo the driveshaft hub nut. A decent bearing kit should include replacement bolts with locktite on and a new hub nut, it took me 2 hours because the 4 bolts and hub nut are very tight.

[paintman]

SuperchargedVR6 said:

Same setup as the MK5 Golf (less the driveshaft) and simple to do. I would strongly recommend researching the hub bolt (part 7 in the second link) because the torque setting will vary if they changed the bolt head and shoulder type. The bolts are all probably "use once" torque to yield, so you'll need those too.

Also check if any of the bolts are the triple square type the Germans love so much, and get the appropriate sockets ready.

If it's a daily car and you're doing this on a weekend, you need to be pre-armed with all the right tools and parts or you could be left stranded if something breaks that you haven't got a replacement for.

Bi-hexagonal. Common on Land Rover/Range Rover/Discovery and others. Normal 12-point (bi-hex!) socket.
The fun starts if you've got a vehicle with a lot of Torx fasteners, male & female & some caliper slide bolts ends are female hexagonal sockets so need the right sized hex key but it's a good excuse to buy some new shiny things

Good advice though, as you don't want to have things partially stripped & find you need to put it all back together to go & buy a tool!

Edited by paintman on Wednesday 1st February 13:36

[Mr2Mike]

Pan Pan Pan said:

No apology required, It just goes to show how long it has been since I have had to change any wheel bearings. Out of pure interest what type of hub bearings do BMW use if it is not a taper roller type?

Deep groove ball races I suspect. As with many modern cars you don't just change the bearing itself, you replace the entire bearing, bearing carrier and hub as a complete bolt-on assembly so there's no messing about pressing races in or setting preloads. Obviously this comes at a cost to your pocket for buying a new hub and bearing carrier when they aren't actually needed.

[InitialDave]

paintman said:

Bi-hexagonal. Common on Land Rover/Range Rover/Discovery and others. Normal 12-point (bi-hex!) socket.
The fun starts if you've got a vehicle with a lot of Torx fasteners, male & female & some caliper slide bolts ends are female hexagonal sockets so need the right sized hex key but it's a good excuse to buy some new shiny things

No, SuperchargedVR6 is quite correct, triple-square. Also known as XZN. It's a subtly different wrenching profile to a 12pt bihex, and they're not compatible - however, you're unlikely to get them mixed up, as every application I've encountered has been an external wrenching for bihex, but internal for triple-square.

VAG have a real thing about using triple-square heads on stuff like head bolts and driveshaft/CV bolts. Other than having to have a specific driver for them, I have to say, they are far preferable to the "oh look, it's chewed itself to buggery" internal hex/allen heads other manufacturers use.

I'm not sure I've even seen them on a BMW though.

Edited by InitialDave on Wednesday 1st February 17:07

[paintman]

I stand corrected You learn something new every day.

[Pan Pan Pan]

Mr2Mike said:

Pan Pan Pan said:

No apology required, It just goes to show how long it has been since I have had to change any wheel bearings. Out of pure interest what type of hub bearings do BMW use if it is not a taper roller type?

Deep groove ball races I suspect. As with many modern cars you don't just change the bearing itself, you replace the entire bearing, bearing carrier and hub as a complete bolt-on assembly so there's no messing about pressing races in or setting preloads. Obviously this comes at a cost to your pocket for buying a new hub and bearing carrier when they aren't actually needed.

Many thanks for the info, I guess it makes sense given the improved technologies involved in modern drive trains, and taking into account the problems which might occur when replacing old style taper roller races, for many the replacement of the entire hub assembly might be the best way. It may be that in many garages now they don't so much have motor engineers, as much as motor vehicle fitters.

[Perseverant]

The modern approach with an all in one hub assembly makes the job easy, the downside being expense. Just please be careful and make sure the car is securely supported. When the big nut that holds it all together is back on its correct torque, the ball races will be held in the hub to give exactly enough play - preferably get a new nut, which if you're lucky might come with the bearing. I also would hope that with a comparatively new car the other fasteners for calipers and so on won't be too bad to shift - it's always worthwhile finding the right tools too, as in so many years of DIY mechanics I've lost count of the times I've had to undo mangled items that feature signs of cold chisels and so on. (OK, a cold chisel can be handy, but don't reuse the nuts!}

[Krikkit]

Pan Pan Pan said:

Mr2Mike said:

Pan Pan Pan said:

No apology required, It just goes to show how long it has been since I have had to change any wheel bearings. Out of pure interest what type of hub bearings do BMW use if it is not a taper roller type?

Deep groove ball races I suspect. As with many modern cars you don't just change the bearing itself, you replace the entire bearing, bearing carrier and hub as a complete bolt-on assembly so there's no messing about pressing races in or setting preloads. Obviously this comes at a cost to your pocket for buying a new hub and bearing carrier when they aren't actually needed.

Many thanks for the info, I guess it makes sense given the improved technologies involved in modern drive trains, and taking into account the problems which might occur when replacing old style taper roller races, for many the replacement of the entire hub assembly might be the best way. It may be that in many garages now they don't so much have motor engineers, as much as motor vehicle fitters.

Those that don't replace the whole housing are deept groove double-row now as well, the taper bearing that needed pre-loading is long gone in my experience.