ZX swivel hub/brake problems

[the_weaver]

My car is a ZX 1.9D Reflex, 1993, no ABS, no power steering, no turbo.

About ten months ago, I had a new front offside wheel bearing, fitted by a garage. The car has always pulled slightly to the left, but after I had the new bearing, the car started pulling to the right. I thought it was a bit strange, but as they'd done quite a bit of dismantling, I thought maybe they just hadn't lined something up right on re-assembly. I carried on using the car, and I haven't done much mileage in it since then.

Recently I put it in for the MOT, and it failed on uneven front brakes. The garage said that new front pads and discs would sort it out. I already had some new discs and pads, so I let the garage fit them. When I got the car back, the brakes didn't feel right. I drove about for a bit, thinking that the pads needed to be bedded in, but the brakes were still not right.

I put the car up on axle stands, to see what the problem was. Once the brake pads were out, I could see that the problem was that the sliding caliper (made by Bendix) was not sliding. One of the metal slides was locked up, the other one moved ok. The rubber gaiters had some holes in the them. So I got some new gaiters, and cleaned up the slide that was seized. Both slides were now sliding ok. Before fitting the two new gaiters, to the one slide that I dismantled, I decided to try the caliper on the hub. I was shocked to find that it didn't slide. It slides ok when the bolts are loose, but when you tighten the bolts, it locks up solid.

I've got a swivel hub from a Peugeot 306. I tried bolting the caliper to that, and it slides ok, even when the bolts are tight. So, I'm now suspecting that there's something wrong with the ZX hub. I've inspected the caliper mounting points, on the hub, and one of them does look like it's closer to the disc than the other one. I tried taking some measurements with a digital caliper. I measured from the flat top face of the mounting points, to the disc, using the rod that extends out of the digital caliper. I got varying readings and found it quite difficult to get accurate measurements. However, it does look like there might be a difference of up to 1 mm. What I forgot, was that my brake disc is only held on by one screw, as the other one broke off in the hole. So it's possible that the disc wasn't true when I took the measurements. I should have used the four wheel bolts to hold the disc on properly. I put a spirit level across the mounting points, and that looks out. Looking at the back of the hub casting (which is round, not machined) it does look like one mounting point is closer to the disc than the other. That mounting point also looks like it may be at an angle.

The problem with the car pulling to the right, started when the garage changed the offside front wheel bearing. The pulling is probably caused by the locked up brake caliper slides. When the garage pressed out/in the wheel bearing, I think they may have supported the swivel hub on the caliper mounting points. It is a nice flat area on a mostly curved hub. They probably bent the mounting points when pressing the bearing. The problem with the car pulling to the right started at that point, but the feel of the brakes became worse when the new pads were fitted.

When the wheel bearing went, I tried removing the swivel hub myself. However, the top clamp bolt on the swivel hub was rusted in place. I got the nut off, but I couldn't remove the bolt. I tried wedging the clamp apart, but it felt solid. I think that the bolt may have been rusted in at both ends, and that the clamping force was still there even though the nut was removed. That's why I took it to the garage. The chap in the garage said he removed the nut, and then hammered the swivel hub off. The original bolt is still in there. I'm now wondering whether he tried to remove the hub with it still clamped on. In which case, he might have hammered it very hard. Maybe he bent the caliper mounting when he hammered the hub off. There is a mark on the side of the caliper. Also, when fitting the new pads for the MOT, the garage must have had to move the seized caliper. I expect they hammered the caliper across to get the new pads in. This could have bent the caliper mount. There were some marks on one of the slides which might point to it being forced over.

The garage is the same garage that put my cambelt on "one tooth out on the injection pump". They then adjusted the pump all the way to the end of the slot, to try to compensate for it. I gave then a telling off after that, and I swore I'd never go there again. Unfortunately, the wheel bearing had to be done quickly, so I went there again, and now I'm paying the price. They've well-intentioned, but just hopeless. I've decided to fix this problem myself, if I can, as they'll only break something else if I take the car back there.

I'm now wondering what my options are for fixing this problem. Has anybody has this before? Any advice would be very welcome. The first thought I had was to just hammer the caliper mounting point back into position. I was thinking about clamping a big vice onto the lug and hitting the vice with a hammer. However, I expect I might bend/break something else, like the track rod end. I could take the swivel hub off and hammer it against the ground I suppose. I've got a feeling that it might be difficult to get it back into the exact position required for the slide to work. I know that the slightest bit of corrosion will stop those slides from moving, so they need to be spot on. How much force would it need to bend these mountings? Is it vitally important that the caliper mounting points are perfectly flat, so I shouldn't try bending it back, or is there some play in the system which might cope with a bit of error?

The other option is to source a replacement swivel hub. I think this might be the best solution. I have got a hub from a Peugeot 306, but I'm not sure if it will fit. There are two types of swivel hub. There's the old type, like my ZX hub, which is solid. There's also a newer type of hub, which is hollow, with a hole in the top, which may be for ABS wiring. Does anybody know whether these two type of hubs are interchangeable? They look similar, but the ZX hub has a 14mm diameter lower balljoint spindle, and the Peugeot 306 has a 16mm diameter balljoint spindle. I have got a 16mm ball joint as well, so I could use that, but are the hubs interchangeable if you use the right balljoint? The Peugeot 306 hub has an ABS ring, which the ZX hub does not have. I read in a Peugeot 405 service manual that the lower arm has been modified and you should get the right version and not mix-and-match. Maybe the "modification" to the lower arm was just the balljoint size?

My plan of action is to remove the entire strut, so I can get out of the weather, and work on it inside. I think that the clamp bolt at the top of the swivel hub may still have the bolt which is rusted at both ends, so it will be a lot easier to get that sorted out on the bench, rather than on the car. I'm a bit concerned that it's going to be impossible to remove, so it might be better to source a complete strut with swivel hub and just put that on the car. If the garage hammered the swivel hub off and then back on again, with the clamp still clamping due to the rusted bolt, then they could have caused a lot of damage. I wonder if the shock absorber tube, or the top mount bearing have been damaged. I have heard some rattles when going over bumps, since the work was done. Also the steering didn't feel the same as it did, but that could be linked to the binding caliper.

When sourcing a swivel hub/strut, what car types would be compatible? Would a hub/strut from a ZX turbo diesel be the the same as mine?

Paul

[the_weaver]

In the old gsfcarparts catalogue is says that ZX's have a lower balljoint spindle diameter of 16mm for cars with no power steering. Cars with power assisted steering have an 18mm spindle diameter. Yet on the citroen service website it only quotes one part number for the swivel hub carrier - 364753 I'm confused by this. Is there a different hub for PAS cars? Are Citroen using the same part number for two different products? Are you supposed to tighten the hub clamp down to whatever size balljoint you have?

EDIT: I'm now thinking that there's only one size for ZX's - 16mm. The cars with PAS have a different balljoint type, but I think the spindle size is still 16mm. It was gsf's part numbers that confused me - N42416 and N42418.

Paul

[Spaces]

Car comes back from garage repairs pulling to one side. You have a look at the hub and see it has been distorted. Politely but firmly return car and explain that the hub appears to have been damaged during bearing change. Ask them to explain what you have found if they look quizzical. Additionally car fails MoT due to uneven brakes. I'm surprised you don't insist it's repaired by them - a few carefully placed blows with their hammers is probably the answer, unless really badly distorted. It's a lack of holding bad business to account which allows them to continue damaging customers' property and getting away with it.

Hope the problem is sorted soon, maybe since it's a while since the damage was done you prefer not to return car to the garage. Look for any evidence of them having already tried hitting the distortion back into shape - if so then it's possible another hub would be needed. A specialist with a few scrap cars should be able to sort out what you need quite inexpensively.

[the_weaver]

Thanks for the reply, Spaces. I've got no problem with complaining to the garage, and getting them to redo the work. I've done it many times before, with them, after the previous saga with the cambelt. They're actually very good about redoing the work. They don't argue, they just accept that they've done it wrong, and do it again. The problem I've got, is that they're not very good. They do one job, but break something else. When they did the wheel bearing, they damaged the outer driveshaft gaiter. They replaced the gaiters for nothing (with me providing the parts), but then damaged the rubber boot on the lower ball joint. They then replaced the balljoint for nothing (with me supplying the part) and this time didn't damage anything else. It's just the hassle of having the car in the garage three times for one job that annoys me. So, at times I just decide to do the work myself instead. It's actually easier, and then you know it's been done properly. As long as the weather isn't too bad, I can do most things myself.

I've now ordered a swivel hub from a scrapyard on ebay. When the hub arrives and I know it's the right one, I'll remove the complete strut, and get to work trying to free up the rusted clamp bolt. While I'm at it, I'll check the top mount on the strut to see if it's been damaged.

Paul

[citronut]

if the pinch bolt holding the strut is still seized in place at both points, it is very unlikely the garage removed the hub from the strut, they probably removed the hole strut and worked wqith the complete unit,

to get the bolt out you will need to heat up the points the bolt goes through the hub carrier, but mind you dont get to much heat at the shocker,

also if you look at the swivle joint/s listted on service citroen it seems to only list a 16mm swivle pin,

if i remember corectly the diference is the mouting bolt to arm sieze over the modle range,

3640 43
ARM BALL-JOINT
DIAM 16
- EXCEPT POWER STEERING

3640 42
DIAM 16
- POWER STEERING

E459704
SUSP JOINT
- EXCEPT POWER STEERING AND AGE >= 5

E459705
- POWER STEERING AND AGE >= 5

regards malcolm

[the_weaver]

Malcolm

They did remove the swivel hub from the strut. I went down to the garage and saw it. They also told me they'd hammered it off. What I don't know is whether the clamp bolt was rusted at both ends, or whether it had (been) freed up. I know they took the nut off, but whether they realised it was rusted is not clear. I told the boss, but maybe he didn't tell the mechanic.

Thanks for the info about the balljoints. It does look like they're all 16mm. When it says "AGE >=5" does that mean "cars more than five years old" and is it measured from today's date?

Paul

[the_weaver]

I've now got a replacement swivel hub, from the scrapyard. The bearing turns ok but feels a bit "heavy" or tight to me. The wheel bolt holes in the centre hub were a bit rusty. I'm in the process of cleaning the threads on the wheel bolt holes, using a wheel bolt. They clean up ok. However, I am thinking of getting a new bearing put in, and changing the centre hub for a better one at the same time.

I've had a look at the swivel hub, to see where you can support it, when pressing the bearing out. Pressing the new bearing in looks easy enough, as there's a large flat area on which to support the swivel hub. However, I can't see anywhere obvious to support the swivel hub, when pressing the old bearing out. As it could take twelve tons to get the bearing out, it needs to be supported properly. The only flat area is the brake caliper mounting area. I can see why the garage used this, and ended up bending it. It's the obvious place to use, for somebody in a hurry.

I did a bit of research and found the SNR bearings website. The following pdf document covers the installation of bearings:-
http://www.ntn-snr.com/autoaftermarket/ ... entID=1279" onclick="window.open(this.href);return false;

On page 4, section 7, it shows a picture of the swivel hub supported on a large metal tube, for the purposes of pressing the old bearing out. It states the following:-

Replace the inner race and ball
assembly into the outer race
(which is still in the hub carrier).
Put the hub carrier under the
press, supported on a wedged tube.
Using a suitable diameter tube,
push on the inner race of the
bearing, in order to remove the
outer race.

It says to use a wedged tube to support the hub carrier. Looking at my swivel hub, I can see a ring of angled metal around the bearing outer race. Is this what your supposed to support the swivel hub on, when pressing the old bearing out? It's not very big. I can't see many garages having the right bit of wedged metal tube to support the hub there. The angle would have to be right. It would have to be bought, or made on a lathe. I'm starting to have sympathy with my garage now. No wonder they did it wrong. It's not easy, or obvious how to do it right. I think Citroen have "designed in" a problem here.

I think that pressing the old bearing out is a difficult job to get right. So, who I can I trust to press it out? Garages must do hundreds of these bearings. I think that a lot of swivel hubs are getting bent during this operation. How many garages will have the correct bit of wedged metal tube to fit? Are there any garage equipment companies selling these wedged tubes? I can't believe that thousands of garages are making these things themselves. Surely somebody must be selling them.

Do the Citroen main dealers have this angled tube? Does anybody know? How much would they charge for fitting a new bearing to a swivel hub?

Paul

[citronut]

have you got a local engineering work as they should know how to press the bearing out, without causing you worry they might damage the hub carrier,

also if the bearing in the hub you bought feels firm to turn, as long as its smooth i would say its just packed with grease causeing the drag, and would not worry about fitting a new bearing,

regards malcolm

[the_weaver]

Malcolm

I'll have to have a look for an engineering company. There's an engine rebuild place close by, but they usually only do other work when they are not busy.

The bearing does feel firm, but I thought it felt a bit too firm. In new bearings, the grease is soft. In old bearings, the grease goes harder. It feels like harder grease, but not rough yet. Anyway, the main reason I want to change the bearing, is that the centre hub had rusty bolt holes (for the roadwheels). I cleaned them up, but the rust comes from somewhere, and that somewhere, is the metal in the threads. The threads must have lost some metal, so I'm wondering whether they're as strong as they were. There's not much metal in a thread, and it's holding the wheel on a ton of car, going round a corner at 70mph.

I think I saw somebody placing a knife edge bearing puller in between the centre hub and the inner race of the bearing. I think that might allow the centre hub to be pushed out, whilst keeping the bearing in place. The bearing puller was placed in from two sides, as in two semi-circles coming together to form a circle. It sounds interesting. I wonder if I could use threaded rod through the centre of the hub, to change just the hub. If I could do that, then I'd probably keep the existing bearing. Would hammering the centre hub out. or using a slide-hammer be ok? I'm not actually hammering the bearing, just the hub.

How much force would it take to remove and refit just the centre hub? If it's only a ton, then I could probably do that with threaded rod. If it takes more than a ton, then I could get somebody to do it on a press, and keep the existing bearing.

Paul

[citronut]

if you remove the drive flandge you will pull the outter inner race out with it, as its very unlikely you could get anything inbetween the drive flandge and the hub carrier to retain the outter inner race,

regards malcolm

[the_weaver]

Malcolm

You're right, there's no space between the flange and the hub carrier. I got the idea when I saw somebody changing a bearing on youtube, with the hub carrier still on the car, but it was for a completely different car.

Paul