ZX TD - Front wheel bearings can't take the torque ???

sooty · Post by **sooty** » 07 Nov 2005, 19:19

I increased the Power/Torque output of my ZX TD some 15 months ago. Since then I'm changing the L/H front bearing roughly every 6 months. I use good quality bearings (SKF) not eastern european quality.

Most of the journeys made are mostly Motorway (90%), but the increased torque is used at joining Motorways or joining roundabouts.

The question I have to ask is there a Heavy Duty version of these bearings to withstand the high torque these engines can push out when the Boost and Fueling is increased.

citronut · Post by **citronut** » 07 Nov 2005, 20:43

i would not think that this could cause your bearing prob,because if it did it will not just select one bearing on one side only
regards malcolm

np · Post by np » 07 Nov 2005, 20:48

I had my Xantia boosted to approx 115bhp/185 lbft torque.That was 3 1/2 yrs ago now.Have had no probs what so ever with the extra power/torque.

NiSk · Post by **NiSk** » 07 Nov 2005, 22:21

Having spent ages trying to find out why the LH front disc/ hub/bearing/wheel /tyre on my '98 XM kept buggering me about, I finally got round to swapping the steering knuckle for the one on my old (crashed) XM - principly so that I could pull it apart and find out what was wrong with it. That was a year ago and it hasn't played up since - so my recommendation: go to the breakers and get a replacement steering knuckle.

//NiSk

sooty · Post by **sooty** » 08 Nov 2005, 20:05

NiSk wrote:Having spent ages trying to find out why the LH front disc/ hub/bearing/wheel /tyre on my '98 XM kept buggering me about, I finally got round to swapping the steering knuckle.

//NiSk

What is a Steering Knuckle, you are talking about.

AndersDK · Post by **AndersDK** » 08 Nov 2005, 20:24

The front hub assembly.

If this has been damaged (by heat f.i.) it may stress the hub bearing by a small amount of ovality - enough for a premature bearing failure.
You're certain that new bearings has been filled with grease ?

sooty · Post by **sooty** » 08 Nov 2005, 21:18

"You're certain that new bearings has been filled with grease ?"

I would have thought from my engineering days that 'SKF' would have already filled the bearing with the grease required, as too much can do more harm than good.

The only heat applied would have been the welding of a run of weld inside the old track, to shrink the track to ease the removal. Which would not have been excessive enough to cause distortion. This is an old trick of the trade used for years in engineering.

fastandfurryous · Post by **fastandfurryous** » 08 Nov 2005, 22:06

The load on a front wheel bearing from driveshaft torque is nothing compared to cornering loads and running loads of holding the car up, so I would safely say that the additional output of your engnine has very little to do with the bearing failures.

Plus, of course, a 2.0i ZX will have more torque at the wheels than even a boosted 1.9TD, so I think we can safely discount the boosting being a problem.

I seem to remember someone else on here a while ago having a recurring wheelbearing failure problem on an activa. In the end, it was traced to an incorrect driveshaft being fitted that meant the bearing inner races weren't being clamped properly.

Have you changed the L/H driveshaft at any point recently?

When you change the bearing, are you changing the driveshaft nut too? Once torqued up to the ludicrous lbf-ft that they need, they can tear their threads, and not work properly a second time. Plus, are you achieving the required torque for the driveshaft nut? Very few torque wrenches go anywhere near what's needed. I usually end up with a 20Kg weight on a very long (measured) scaffolding pole to get them right.

How are the bearings failing? do you get runnung surface break-up, or do they run loose?

sooty · Post by **sooty** » 08 Nov 2005, 22:40

The drive-shafts are originals, the nuts are replaced and torqued as required at 320Nm.

The bearings fail by starting to be noisey to the point everyone looks where is the noise coming from and you can't hear the radio in the car. It usally quitetens when cornering as with most bearing failures whether its a tapered bearing or a angular contact bearing as these are.

fastandfurryous · Post by **fastandfurryous** » 08 Nov 2005, 23:01

Are you getting your bearings all from the same place? It could be that they've had a dodgy batch in? or maybe they've managed to contaminate them with some grit? (or do they come sealed in a plastic bag? some do, some don't)

I would try a bearing from somewhere else next time. If that doesn't work, I would be looking at the bearing carrier very suspiciously.

citronut · Post by **citronut** » 09 Nov 2005, 08:49

fastandfurryous wrote:Are you getting your bearings all from the same place? It could be that they've had a dodgy batch in? or maybe they've managed to contaminate them with some grit? (or do they come sealed in a plastic bag? some do, some don't)

I would try a bearing from somewhere else next time. If that doesn't work, I would be looking at the bearing carrier very suspiciously.

i would also be looking at the person that fitted them and how they where
fitted
regards malcolm

Stewart(oily) · Post by **Stewart(oily)** » 12 Nov 2005, 10:37

These bearings easily trasmit lots of power and usually last 100k miles, they are however easy to damage if not pressed in properly, they should be pressed only on the outer track, any load applied to the inner will seriously shorten the life of the bearing.
Stewart

sooty · Post by **sooty** » 06 Dec 2005, 18:28

Ok The time has come to change the bearing yet again.

As suggested about changing the hub.

Any suggestions of what I should pay for a pair of front suspension legs complete with springs, disc's and hubs etc. from a scrappy.

fastandfurryous · Post by **fastandfurryous** » 06 Dec 2005, 19:22

Suspension legs should be a tenner each, although you may have to forego the discs.

I *think* the zx has a similar system to the 405, which means the hub carrier can be separated from the suspension leg, which would mean you don't have to change both sides.(only change one hub carrier).

It would be interesting to pull the old dead bearing to bits, as you can usually see where it's failed, which can tell you a lot about what's causing the problem.

Stewart(oily) · Post by **Stewart(oily)** » 06 Dec 2005, 19:22

You dont need the complete struts, just the hub, theres a pinchbolt to remove and " reassembly is the reversal" as far as price goes, it depends how friendly they are around my area, are you running Volcane struts?
Stewart