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        General >> Problems >> rear wheel bearing
        
(Message started by: fix-and-foxi on Feb 10^th, 2021, 8:21pm)

Title: rear wheel bearing
Post by fix-and-foxi on Feb 10^th, 2021, 8:21pm

Hello,

my Scorpio. 2.0i 16V, Estate, ´96 makes my very angry.
I bought it in 2008 and till last week I spend much time and money for service and repair. Without this forum I will have never this chance -many thanks. But now the car is in the ulmost danger to scrap -slowly and painful!

Okay, what happens:
The Scorpio needs rear wheel bearings every time, in the 10years and nearly 100.000 km I changed the rear wheel bearing min. 5 times.

Usually it begins with quiet rumble, a short time later its rumbled lik a sackful nuts -and the bearing broke in an lot of parts.

Last week the right rear bearings brokes down total unexpeced on the highway by nearly 170 km/h, the right rear wheel blocked for several moments, the car tryed to spin out in the pampa.

So not!
If I want to scrap the Ford, I do it by myself, not by Ford!

Problems:
I use by repairing new ford hubs (so cheap, less than 400 EUR/pcs.) and SKF bearings (rep.sets).

If the bearings are mounted to the hub, than it takes place that the inner bearing shell is nearly 1.2mm longer than the hub.
That means, if the big central nut is screwed (at least 270NM),
the bearing shell will be deformed.

I called SKF, and they informed me, that it will be okay. http://www.fordscorpio.co.uk/YaBBImages/nono.gif
SKF Bearings VKBA 3485 are identical to Ford 1046767 SKF Bearings as 100% OE supplier.

By the first test drive of an bearing the hub gets at first very hot, for nearly 50km it grows up to 70°C.

The car is now in a garage. The mechanics discussing the problem. They told me, that in the past there could be special distance plates to the outer bearing shell. So the inner bearing shell gets the right bearing clearance.
But I have never seen or read about such distance plates.

There a two problems.

At first, the 270 NM deformed the inner bearing shell.
At second, the bearing clearance gets to small.

As far as I can see, the solded SKF Bearings (Rep.Set) are not compatibel to the Ford rear wheel hub.
The hub is to short (1.2mm)
Bot other supplier seemes to use the same measures. http://www.fordscorpio.co.uk/YaBBImages/huh.gif
Therefore I ask if I have mounted the bearings in correct way.
Means, both inner Bearings forms like a "V".
Ot could it be, that the inner bearings forms like a roof?
(By the way; I have never seen such a construction)

I try to attach pic/pdf file, but I do not know how it works.

Title: Re: rear wheel bearing
Post by Tompion on Feb 11^th, 2021, 1:38am

Hi,

Yes the 2 inner tracks are slightly longer than the length of the hub. I've not measured it but 1.2mm sounds about right. I know it seems odd but the inner tracks have to be clamped together to get the correct clearance - it's not like in the past where you purposely left a little play in the bearings.
Any I've worked on the inner tracks are between a tight fit and a very tight fit, if they've turned on the hub so they are a loose fit they probably won't last long - they are more likely to deform if they aren't a press on fit.

There must not be any nicks where the outer tracks seat in the carrier, if they don't go fully home even by a thousandth of an inch there will be excessive pre-load. It is best to press them into place, as with any bearing you never put pressure on the tracks or rollers, they won't last if you do.

It is best to assemble the hub to the carrier off the car using a press (ensuring once again that no pressure is put on the tracks or rollers) & fit it to the car as a complete unit. If the bearings are tight on the hub & you try to fit it with the carrier on the car you will be putting pressure on the tracks & rollers which will cause flats leading to premature failure.

Use good quality grease (I used the Ford grease).
Everything needs to be spotlessly clean including your tools.
Push the seals right in - don't leave them flush with the edge of the carrier (I had one where the seal had been torn by rubbing on the hub & bits had gone into the bearing because it wasn't pushed in far enough by whoever assembled it).

Having pressed it all together I like to clamp it all together using a suitable bolt and spacers to make sure it spins freely - should be smooth but the seals make it stiff.

Having put it on the car and tightened the centre nut fully it's worth unbolting the carrier and pulling it away from the arm, you'll find there's just enough room to be able to turn the carrier on the hub & check it turns smoothly with no tight spots.

Title: Re: rear wheel bearing
Post by PJDavis on Feb 11^th, 2021, 9:21pm

Hi Guys

Twice I put new bearings into second-hand or my own hub, and twice those new bearings failed after only less than 5k miles. Once on my own Movvy, and once on another Scorpio. Then I bought a hugely expensive pair of rear hubs, and fitted with new bearings to 'Movvy', completely different fit, and lasted, well probably still lasting! Certainly did about 50k miles whilst I had the car. Hubs are very expensive, I think about £140 each, but old hubs with new bearings didn't work very well. I think I might even still have a new hub and new Ford bearing I bought as spares, unless Roy has them?

Peter

Title: Re: rear wheel bearing
Post by a900one on Feb 11^th, 2021, 10:43pm

I have a few sets of rear wheel bearings and thought about replaceing them, just in case. Think I will leave well alone.

Title: Re: rear wheel bearing
Post by Simmo on Feb 12^th, 2021, 8:24am

The main thing with replacing these items is to ensure the correct torque is applied on assembly......then..... after a hundred miles or so re check it. The nut securing the bearing is a large one, outside the scope of most DIY socket sets, and requires 3/4" drive bar to remove it. The same goes with reassembly. The average 1/2" Torque wrench will not go high enough so a 3/4" one is needed.

If you read This article by Snoopy (http://www.fordscorpio.co.uk/rhubs.htm) it might help.

Title: Re: rear wheel bearing
Post by fix-and-foxi on Feb 12^th, 2021, 11:45pm

Hello,

thanks for your informations.

The real bearing changing was done in the past by the articel von Snoopy.... there is helpful shown how it works.

I called "old" ford mechanics here in germany, employees by ford garages which made the service and repair to Scorpios time -and sometimes till today.

It takes place, that there were problems with the bearings.

The inner bearing shells has mounted "blocked" together.
But there is a small gap between the both inner bearing shells.
(SKF Bearings, Rep Set, see above)

If so, srewing up the main central nut will damage the bearing.

Its a problem, which happens often.

I do not know, if the inner hub is wrongly manufactured, the housing (outer part of the bearing housing with the crosspiece middle (germ. Steg) -sorry for my english), or the bearing itselfs.

The inner part of the bearings cannot work with pressured together by strange forces-the inner shell of the bearing must only be pressed to the hub, by zero bearing clearance.

Its correct, that all defects by mounting used hubs make even much more problems to the bearings.

If I understand the info I get right, the after part bearings are not the same which are used by Ford....

The mechanics modified now the whell hub (housing) by turning the "crosspiece" a little bit thinner (o.3mm), and so the inner wheel shell are blocked togehter when the main nut is screwed up to 270NM -without blocking itself. By the way, I fear that 0.3mm was a little bit too much for the beearing clearance, but we will see how it will work.

We measured the temperature by the first test drive and the new bearing do not go hot.

Fazit:
The pressure of the main nut (270NM) is absolutely necessary to block the bearing to the hub.
But if the bearing are not correct blocked without strange forces, the pressure of the main nut damages the bearings. If so, the bearings get very hot and goes down.

Taper roller bearings are working tension-free.

By the way, a new hub costs now 340.00 EUR.

Oh dear -sorry for my english-

BR
fix-and-foxi

Title: Re: rear wheel bearing
Post by Tompion on Feb 13^th, 2021, 10:58am

Glad you've got it sorted, keep an eye on it & mark the nut with paint so you can see if it moves.

Illustrates why it's a good idea to do a test assembly with a bolt and spacers (in place of the hub) before fitting to the car, a problem would be obvious without causing damage.

Title: Re: rear wheel bearing
Post by theogrenietis on Mar 16^th, 2021, 8:15am

This is great stuff. Have had problems on rear bearings on sierras and scorpios for ages, but never got to the bottom of it.