Omega Owners Forum

Omega Help Area => Maintenance Guides => Topic started by: feeutfo on 15 August 2009, 02:25:00

Title: how to replace rear donut bushes.
Post by: feeutfo on 15 August 2009, 02:25:00
There is a special fitting tool associated with this job, but its more than possible to replace both rear bushes without it, as follows;

Jack the rear corner of the car onto a stand and chock the front wheels in usual manor. But try to get the car as high as safely possible to give you room to work. Remember you will be applying leverage and pulling the car about so make certain its solid and cant move.

Elite owners may find this link usefull to follow prior to jacking, saves some effort and give better clerance under the car. http://www.omegaowners.com/forum/index.php?topic=90617.0

Once on axle stand place the jack under the trailing arm to support it and hold it in place, but dont worry too much about holding the arm in position as the effect on set up is probably minmimal and you may well have to release the jack if (when) things get stubborn later on. If you have access to an air line and an air ratchet then that will help.

So car and arm supported, remove the 3x 15 mill bolts holding the triangular plate on under rear door/forward of rear wheel and the 18 mill( hardened socket is wise, i split a normal one) centre bolt that passes through plate and bush to chasis captive nut, you will now have access to the bush itself.Pic of plate and 18 mill centre nut, you can see the bush behind
(http://images.omegaowners.com/images/guides/rear_subframe_bushes/14082009754.jpg)

Remove bush.
 This depends on the bush state to an extent.
First method to try is with a claw hammer( cross pain hammer or crow/pry bar will do also, anything that fits in the slot and gives leverage within the space under the car)   insert the claw end into one of the 3 lips Mr vx has left on the rim of the bush to leaver them out. Pull side ways or back on the hammer doesnt matter how you do it as long as you work  it out evenly with all 3 slots.
if it comes out skip the next paragraph.

If no joy with claw hammer method and its still stuck in find something to stick in the centre hole of the bush( large screw driver?) and lever it about see if the rubber is comming loose from the metal cup. If so lever/rip/ Mine were seperated from the rubber and i presume this was causing a creak as the rubber twisted in the cup. This remaining metal cup was very stubbern to remove as if glued in. Only hope i could see was to remove the centre rubber and use a baring puller( halfords do one) trouble is there is nothing for the centre bolt of the puller to push on except the chasis which will just raise the car, or pull the arm down, no good. So, as said, you need to remove the centre rubber with spacer set into it if poss and insert something accross the gap in the back of the arm recess( i used 2 allen keys of the appropriate length to bridge the gap) and arrange a socket or block, whatever is to hand, for the centre bolt of the puller to push on. Then arrange the 3 puller arms in the 3 slots on the bush( very fiddely) and wind the bugger out.
As pic below, you can see the idea with 2 allen keys and socket for puller centre bolt. Also shows the state of the cup with rubber removed as it was seperated and failed mot, no suprise it creaks
(http://images.omegaowners.com/images/guides/rear_subframe_bushes/01122008336.jpg)

Fit new bush.
Do this "dry" (no lube of any sort, esp. not mineral/petro chemical based) or you risk them squidging out after a day or 2 and having to do the whole job again.
Place the bush in the recess and force it in as far as you can either with a mallet or, more likely, the jack. Dont worry about releasing the jack currently holding the arm up, it wont fall. Place the jack under the bush and force the bush in by pumping it up, keep an eye on it as you may have to re position the jack as the sadlle pulls away due to its radious action. You will probably find it will lift the car before it is fully home. If so remove the jack and pull down the arm to remove the rubber pad sitting on top of the arm(cussions the arm to chasis)

You now need the triangular plate and 18 mill centre bolt. Turn the plate upside down and of the correct orientation, with the bolt fitted through it, and use that to force the bush in by tightening it into the captive nut through the bush spacer. If the bolt doesnt reach the captive nut because the bush wont go in enough, remove the plate and use the bolt on its own, tighten until the bolt hits the chasis or stops turning(it wont force the bush fully home) and go make a cup of tea, when you come back it should have pulled in enough to allow the plate to be used. Tighten the bolt with plate until it stops on the chasis, bush still not fully home. Now undo the center bolt just enough to place a spacer between chasis and arm then re tighten. I used ever incresing size allen keys as   spacers layed accross the top of the arm tightened onto chasis, start with 5mill width, tighten, undo, next size allen key up, tighten undo, and so on until fully home. Remove spacer( allen key) re fit the rubber pad making absalutely certain it fits over the top of the bush centre spacer and does not get trapped between bush and chasis when you do the bolt and plate back up.

if the centre bolt does not line up with captive nut(arm has moved) at any point during this procedure, couple of methods to try. Its possible to lever on near by 15 mill bolt mounting points, ratchet strap to near by solid mounting points, or if the car is on the floor chock the rear wheel in the appropriate direction and with Extreme care drive the car up against the chock to force the rear wheel and hence the arm over in the direction you need. Hold on the hand brake firmly, turn engine off leave in gear. Then feel if the bolt lines up, do not stick your head under the car with the drive train under tention, in case the car moves, hand and feel only.

Title: Re: how to replace rear donur bushes.
Post by: feeutfo on 15 August 2009, 02:27:50
A quick word on bushes themselves, there is a theory that fitting carlton bushes gives the omega a firmer ride, which they certainly do. The problem is they are set on the spacer at a diferant hight to omega items, so may well fit, but over a 24 hour period slowly work their way out again giving very odd handeling sensations at the rear. as you can see, not the same at all. Suggest genuine vx only, but they may well have to be ordered in, couple of days usually...
OMEGA (on left)                                                                                      CARLTON(on right)
(http://images.omegaowners.com/images/guides/rear_subframe_bushes/18052009582.jpg)


















key words for the search.
Rear donut bushes.
Rear suspension creeking.
Trailing arm bushes
Rear suspension bushes
Carlton bushes
rear end moving
Title: Re: how to replace rear donur bushes.
Post by: razzo on 15 August 2009, 11:04:58
some other pix which may also help if Admins could ammend/delete as they see fit


plate that needs to be removed

(http://images.omegaowners.com/images/guides/rear_subframe_bushes/P1010026.jpg)

bush half in half out

(http://images.omegaowners.com/images/guides/rear_subframe_bushes/P1010041.jpg)

bush removed

(http://images.omegaowners.com/images/guides/rear_subframe_bushes/P1010051.jpg)

the old bushes

(http://images.omegaowners.com/images/guides/rear_subframe_bushes/P1010044.jpg)


HTH
Title: Re: how to replace rear donur bushes.
Post by: razzo on 16 August 2009, 10:41:29
Poly bushes for the rear subframe with old bushes in background, its a good mod & tightens up the backend nicely

(http://images.omegaowners.com/images/guides/rear_subframe_bushes/P1010046.jpg)

 :y
Title: Re: how to replace rear donur bushes.
Post by: feeutfo on 21 August 2009, 23:19:37
The special tool, thanks to Marks dtm.
Bolt and 3 prong plate underneith on the bush face, u shape and nut go on top/back between arm and chasis. Screw the two together through the bush and arm pulls the bush in.

(http://images.omegaowners.com/images/guides/rear_subframe_bushes/DSC001311.jpg)
Title: Re: how to replace rear donur bushes.
Post by: feeutfo on 21 August 2009, 23:31:44
as far as i can tell the torque setting is quoted at 65nm in book of lies, but gives no ref to 18 or 15 mill bolt sizes.... :-/
Title: More on Replacing Rear Donut Bushes
Post by: MarkG on 26 August 2009, 20:59:25
I managed one side tonight. Here are my notes for others comtemplating the job.

First point is ignore Mr Haynes. There is no need to drop the exhaust and do not support the car on the ribbed floorpan as it suggests. I really struggled to find a good place to support the car away from the suspension because you need the suspension to be hanging.  So jack the car on the trailing arm high enough to get the axle stand in here on a wood block. No need to remove the road wheel

(http://images.omegaowners.com/images/guides/rear_subframe_bushes/AxleStandPoint.jpg)

Next remove the triangle shapped plate and the big bolt through the middle of the bush. Leveraging out the bush was totally impossible so I made this tool

(http://images.omegaowners.com/images/guides/rear_subframe_bushes/WindingOutTool.jpg)

using some bent steel, threaded rod and welded on some nuts. It pulled the metal core and rubber insert out no trouble but left the steel surround still in place. After much banging and leveraging it barely moved so I took an angle grinder to it to create a slot into which I could lever a crow bar. It finally came out.

(http://images.omegaowners.com/images/guides/rear_subframe_bushes/LeveragingOut.jpg)

(http://images.omegaowners.com/images/guides/rear_subframe_bushes/CollapsedBush.jpg)

This bush was dated 1999 so it was the original and had done the car for 185,000 miles.

Next job is to put the new bush in. Easier said than done. Again I had to make a tool using threaded rod and welded nuts on steel plates.

(http://images.omegaowners.com/images/guides/rear_subframe_bushes/InsertionTool.jpg)

I turned the plate upside down as well to wind it in. This applies a more even pressure on the bush rather than just pushing on the bush's core

(http://images.omegaowners.com/images/guides/rear_subframe_bushes/WindingBackIn.jpg)

When there is still 1/2 inch showing, remove the insertion tool, put the rubber pad back on top of the arm and jack the arm back up. Then bolt the plate back up the correct way round. As you tighten you will hear the bush squeeze back in.

It won't go all the way. I think its is supposed to be like this. Only when the bush is knackered does it go flush.

Took me the best part of 4 hours.

The other side turned out to be even more difficult because it was not quite are rotten enough for the inner core and rubber insert to put out. Once again I attacked it with an angle grinder to make a slot for the crowbar. A chisel is also useful for prizing in the gap. One more tip; when you are leveraging, apply pressure and hold. Because it is rubber, you will find you get more movement this way.

It's now done and there is no more creaking. If anyone wants to use the puller and insertion tools I made, PM me and I'd be happy to lend them to you. Good luck!
Title: Re: how to replace rear donut bushes.
Post by: Jimbob on 14 September 2009, 11:46:43
The bush partnumber is :

Vauxhall : 90447156  (£44.75+ each)
or
Lemforder : 16063 01
Title: donut bush update.
Post by: feeutfo on 30 November 2009, 16:11:53
Update.

It has become clear that its important to fit the bush with the correct orientation. That being with the void holes/slots nearest the front and back of the car, and with the solid areas, that join the centre spacer to the body, nearest the sides of the car so as to give most resistance to sideways movement, and allow movement for and aft.

Or as another point of refrance, if you look at the back of the bush ,or look from " the top" when viewed in its fitted position, you will see the 3 cut outs used for levering them out. One of the slots points directly at the centre of the bush, position this cut out nearest, or pointing at, the front of the car.

If the bush is not fitted correctly, the car will tramline and wander noticeably at the rear needing correction at the steering wheel. Note this gives no sensation of pulling through the steering, as the car is in effect steering from the back.

If you should need to reposition them, dont worry too much they come out alot easier when new and one even allowed me to force it back in with hammer! However the other was a bit more stubborn for some reason. Both sides re done in 1 hour. If only it was that easy first time round.
Hth.

So to reiterate, the solid sections pointing, or aligned with the rear dif. And the pointing along the line of the subframe arm.
Title: Re: how to replace rear donut bushes.
Post by: Jimbob on 11 March 2010, 20:17:45
Quote
Found a good source of Febi Bilstein rear donut bushes:

http://www.vauxhallworldparts.com/partsearch/partdetail.php?partid=857

Just over 30 quid a delivered a pair!
Title: Some old rear bushes showing construction.
Post by: feeutfo on 08 September 2010, 17:53:08
Picture below shows our very own Jimbobs absolutely mullered rear bushes.

There have been some questions on construction surrounding the metal cup moulded into them, not to be confused with the cup they sit in in the sub frame arm. I suppose we could say the picture shows 3 areas of concern with these, all built arround the centre aluminium spacer.

1 The main part that causes the problem is shown top middle. it's this part that separates from the previously mentioned moulded in metal cup, and would normally be moulded into the metal cup on the right which is,

Part 2, you can see that has been bent over during removal, it's now gone rusty.

it seems it's the rust that causes them to become unbonded. Add in the forces exerted by driving the car and the whole thing just pulls apart causing an odd wandering feeling at the back.

3 is the rubber part that seals the cup in and has the lines moulded in that grip the recess in the subframe. These rarely fail and stay bonded to the metal cup, it can be seen on the left bush under the bent over part of the rusty metal cup. 

(http://images.omegaowners.com/images/guides/rear_subframe_bushes/20100904_001.jpg)