Radius arm bearings?

lexi · Post by **lexi** » 17 Jun 2009, 20:55

Have now replaced all the spheres on 1.9td estate in last 10k.

The two rear ones I did today. I suspected them less than perfect. Reason was that on going round slow corners with very rough holes in road you would hit one a certain way and get a loud thump which went through the car...............as though you had hit a huge pothole.

I was disappointed that no pressure of fluid rushed out of any of these two spheres to indicate a rupture. Have only taken car a short journey and seems to ride smoother (Placebo Effect ?)so we will monitor it.

Thing is I get that creaking from time to time on parking. I thought it may be because car is on a slope?

So why do radius arm bearings creak, and why do they bang if there is no apparent play. Is there rubber somewhere in there that has failed ? (steady guys) .

Wheels look vertical with a square on them.

There is a nut on subframe that you see if you look between tyre and wheelarch........it sits in the same plane as a wheelnut. Is that where lthe bearing is? Give me a run down on replacing procedure anyone?

rory_perrett · Post by **rory_perrett** » 17 Jun 2009, 21:26

If you do a search for arm bearings it will throw up loads of info.

No rubber involved, but the bearings can collapse meaning that surfaces than shouldn't come into contact with each other do.

On my BX the wheels would obviously lean every 100k miles or so signifying that the bearings needed changing.

On my Xantia the car was passed 200k miles with no sign of bearing failure, however strange rear tyre wear reminiscent of a faulty shock absorber lead me to wonder if the bearings were shot. When I changed them they looked to be in fairly good condition, certainly nothing like the BX where I could find a pile of rusty shrapnel where the bearing used to be, but the strange rear tyre wear was cured and the back of the car felt better.

If I remember rightly, the estate uses the same basic bearing as the Hatch (and BX) but different seals meaning that the kits from GSF don’t give you all the bits you need.

Main consideration in doing the job is that you can easily write off the ABS sensor(s) at £60 a shot while trying to get them out of the arm. There is a thread on that as well. I would recommend disconnecting them at the connector on the top of the sub-frame and don’t try getting them out of the arm.

Basically its –

De-pressurise
Remove sphere
Remove suspension cylinder
Disconnect roll bar (Torx required)
Disconnect brake calliper (or remove calliper from arm)
Remove suspension arm bolt.
Remove arm.

Getting the bearing races out of the arm is much easier if you have access to a welder and can run a bead of weld round the race. When it cools it contracts and the race can often just drop out.

Not too bad a job.

Best of luck.

Post by **Peter.N.** » 17 Jun 2009, 22:29

It could be the suspension cylinder thats creaking, the front ones do. If the radius arm bearings are worn, as Rory said you should have uneven rear tyre wear and you should be able to feel movement on the wheels when jacked up.

I have had them fail on BX's and CX's but never on an XM, about the same ilk as the Xantia. Failure is caused by lack of grease so when I have replaced them I have filled the tube between the bearings with grease, never had them go again.

lexi · Post by **lexi** » 18 Jun 2009, 00:48

Thanks guys. Tyre wear is even. Could be the cylinders. Will test car further to see if thumping continues with new spheres.

citronut · Post by **citronut** » 18 Jun 2009, 08:24

the only thing i will add to rory_perrett job description is you dont need to remove the sphere/s or susp cylinder/s,

just with the car properly supported and susp depresureised, jack up one of the rear arms slowly and fully, but gently so not to tip the car off the stands/support, doing this will allow you the move the susp push rod back well clear of the trailling arm

regards malcolm

Post by **Peter.N.** » 18 Jun 2009, 09:26

Yes, but can you then get the trailing arm out? You can't on the XM.

steelcityuk · Post by **steelcityuk** » 18 Jun 2009, 09:57

I've seen a modification somewhere that entailed fitting a grease nipple to the arm so that it can be regreased. If I find it I'll post it up. If fitting a new arm it would be an ideal time to do it.

Steve.

Post by **Peter.N.** » 18 Jun 2009, 10:07

I had thought of doing that, but in view of the fact that i have never had one go on an XM I sort of forgot about it. If I have to take an arm off though, I fill the space between the bearings with grease.

citronut · Post by **citronut** » 18 Jun 2009, 11:56

Peter.N wrote
"Yes, but can you then get the trailing arm out? You can't on the XM."

yes you can with no trouble on a XANTor even CX, and i cant see why it would not be possible on the XM,not that i have done one on an XM, might be the chines puzzle syndrom

regards malcolm

Post by **Peter.N.** » 18 Jun 2009, 12:46

Hi Malcom

I had one out last week as the ABS sensor had gone o/c and it was cheaper to swap the arm. I struggled every which way to get the arm out but it wouldn't come past the cylinder, then I read the Haynes BOL and it told me to take the cylinder out, which I did, and it came out a treat. I have just looked in the Xantia book and it also says you have to remove the 'suspension hydraulic unit' so I must have missed something.

Peter

lexi · Post by **lexi** » 18 Jun 2009, 13:54

Ok guys lots of good stuff to mull over. I would imagine that towing caravans would put the pressure on these bearings.

citronut · Post by **citronut** » 18 Jun 2009, 16:21

Peter
i have on ocasion strugled to unhook a rear arm from XANTs/BXs, but it was because i did not have the car clear of the ground enough, for the arm to hang down enough to get the right angle for it to unhook from the sub frame side member

regards malcolm

Post by **Peter.N.** » 18 Jun 2009, 17:20

I had mine on a ramp!

citronut · Post by **citronut** » 18 Jun 2009, 19:48

thats cheating Peter, but even still was it a wheel free ramp or did it just use floating ramp jacks,

if the later you could still be without enough clearance

regards malcolm

Post by **Peter.N.** » 18 Jun 2009, 21:33

Hi Malcolm

Its actually a home made ramp. Our land is on a slope, there is a level area of concrete alongside the garage with a wall at the back about the height of an oil drum, you can drive to the top of the wall I then have two large pieces of timber about 8' long, the far end of which are supported by two oil drums. Sounds crude but its very effective. It puts the wheels just at the right height to work on brakes, suspension etc and I have a stool to sit on which gives me just the right height to work underneath - worth its weight in gold.

I have just replaced the timbers as after about 35 years they were beginning to go a bit rotten.

I have two small trolley jacks that I can use on the ramp to raise either or both sides

In answer to your question - yes, there was sufficient clearance to drop the arm right down, what happened if you tried to tilt it right down, was the projection that goes between the bump stops stopped it from being withdrawn. I could only pull it out straight but the suspension cylinder was in the way. Is the Xantia different?

Peter