W124 - Rear Suspension - Lower Bush / Bearing

[Number_Cruncher]

A cautionary tale;

After becoming annoyed with noises from the near side rear suspension of my E300D estate, I poked and prodded the suspension arms, and came to the conclusion that it was likely that the lower bush (number 8 on the link below) needed to be replaced.

http://www.detali.ru/cat/oem_mb2.as...GM=717.433&CT=F&cat=44R&SID=35&SGR=075&SGN=04

Having been bitten by this, I think I should warn that it probably isn't really a DIY proposition. However, here's how it went;

Initially, I tried to replace the joint in-situ, using an old Ford Cortina rear axle void bush tool. Happily, it's about the right size, and I was hopeful that this was going to be a quick job.

The void bush tool did fit, but, the bush was in place so tightly that I snapped the through bolt, an M12 grade 14.9! Not best pleased!

So, I had to remove the hub as an assembly, and use my bench mounted vice to push the bush out.

Some points along the way;

The driveshaft is held by a 12 point 30mm nut. This is FT, and, it's best to loosen this with the wheels on the ground (take the centre cap off the alloys). When replacing, the torque is 200 to 240 Nm, *with the thread and the bearing surface of the nut oiled* These days, being a desk bound wimp, I used a 4:1 torque multiplier, but, it was still tight.

Take some piccies of the handbrake shoes and mechanism before you take it apart. If you aren't used to them, it can be tempting to try to put the springs back on the wrong way.

A three legged puller will come in handy if the driveshaft splines have rusted into the hub flange. A scotchbrite pad, or, the green rough part of a kitchen scourer is really good for cleaning rust out of the depths of the splines both on the shaft, and in the hub.

Before pushing out the old bush, take a couple of piccies - as the casting is shaped, it's not really obvious where the new bush should be pressed in to - there's no stop, or obvious surface to line up against.

The new bush costs about £25.

On the various arms supporting the hub, these should only be tightened when the driveshaft is horizontal - if you leave the lower bush until last, the natural spring in the arms will tend to hold the hub in the right place anyway. The M10 bolts (17mm hex head) should be tightened to 45Nm, while the M12 bolts (19mm hex head, 70Nm)

I did not remove the inner bolt of the tie rod (the arm with a ball joint and taper fitting) as this is an eccentric bolt, and I would need to re-align the suspension if I disturbed it. This made the removal of the hub a bit of a struggle, but, it is possible.

After fitting all the other arms, push the hub down into the lower arm - a sturdy phillips screwdriver is helpful for aligning the hole in the bush with that in the lower arm. The bolt which secures this bush is torqued to 120 Nm.

I hope I don't have to do the other side anytime soon! The good news is that the noise has been fixed - which is nice!

(Jet Tech - you had a lucky escape when you fitted your new backplates!)

 

[Alex Crow]

it is a tricky and time consuming job. i have an arrangement of old bearings and bits and bobs to aid bush removal/fitting in the press; i never do them in situ. i am sure klann do an hydraulic tool for the job which may enable them to be done on the car, sadly the management are unable to invest for the future.

 

[Bolide]

I had this done on one car. The symptom was a slight creak when moving off or on slight suspension movements. Not easy to diagnose but that's why I use a specialist

Nick Froome
www.w124.co.uk

 

[Number_Cruncher]

>>The symptom was a slight creak when moving off or on slight suspension movements.

Yes, that's a good description of the noise.

 

[brianbrian]

You can also get a slight creak when you sit in the car if the hand break shoes need adjusting not to be mistaken for suspension wear. Hope this helps

 

[Number_Cruncher]

You can also get a slight creak when you sit in the car if the hand break shoes need adjusting not to be mistaken for suspension wear. Hope this helps

Yes, I can imagine that - in my case, the noise was most noticeable shortly after setting off.

I had the usual "fun" while adjusting the brake shoes - I'm getting [a bit!] better, I only went the wrong way and backed them fully off once!

 

[brianbrian]

Once you know which way to adjust break shoes up it pays to put^up in your book for when you adjust in next 5yrs or 30000.

 

[kth286]

N/Cruncher

How much time should be allowed for this job doing it your way ??????????

 

[Number_Cruncher]

To my embarrassment, the job took me over 4 hours.

However, in my defence, some of that time was taken in the aborted in-situ removal effort, and some was taken in finding the right combination of old bearing races and sockets, and then grinding bits out of them to suit to fit the shape of the hub casting to use as drifts and cups while pressing the bush out.

Now, with the method and "special tools" sorted, I would aim to do the job in about 2 hours.