Rear spring removal

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dazthephot
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Rear spring removal

Post by dazthephot » Sat 15 Feb, 2020 22:18

I have a broken spring O/S/R and there’s a couple of ways to remove them. Most seem to favour using a pry bar to get the spring out after you’ve dropped the trailing arm. Would spring compressors be better?


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NZ00Z3
Joined: Thu 23 Jun, 2016 02:26
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Re: Rear spring removal

Post by NZ00Z3 » Sun 16 Feb, 2020 05:42

Usually, once you remove the bottom shock bolt, you can drop the trailing arm enough to wriggle/pry the spring out and back in again.

Not sure if there is enough room for a couple of spring compressors.

Mike Fishwick
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Re: Rear spring removal

Post by Mike Fishwick » Sun 16 Feb, 2020 08:47

I have used spring compressors, which make the job a lot easier than forcing things with a crowbar, but even then you must get the compressors into the correct position.
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dazthephot
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Re: Rear spring removal

Post by dazthephot » Sun 16 Feb, 2020 17:53

Mike Fishwick wrote:I have used spring compressors, which make the job a lot easier than forcing things with a crowbar, but even then you must get the compressors into the correct position.
Not much room on the rears as they’re quite there tightly compressed anyway.


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dazthephot
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Re: Rear spring removal

Post by dazthephot » Sun 16 Feb, 2020 17:54

NZ00Z3 wrote:Usually, once you remove the bottom shock bolt, you can drop the trailing arm enough to wriggle/pry the spring out and back in again.

Not sure if there is enough room for a couple of spring compressors.
I’ll try the pry bar method first and see how hard it is.


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Mike Fishwick
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Re: Rear spring removal

Post by Mike Fishwick » Mon 17 Feb, 2020 08:53

Yes, the compressors are a tight fit, and will only do the job if fitted in the correct positions, but it is preferable to straining the inner CV joint by using lots of force on a crowbar, which is really butchery! I supported the trailing arm at it maximum drop angle to avoid strain on the CV joint and its boot before removing the spring.

It is a good idea to also replace the rubber spring seats, which are available in different thicknesses to correct uneven ride heights when carrying the normal load.
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dazthephot
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Re: Rear spring removal

Post by dazthephot » Mon 17 Feb, 2020 09:49

Mike Fishwick wrote:
Mon 17 Feb, 2020 08:53
Yes, the compressors are a tight fit, and will only do the job if fitted in the correct positions, but it is preferable to straining the inner CV joint by using lots of force on a crowbar, which is really butchery! I supported the trailing arm at it maximum drop angle to avoid strain on the CV joint and its boot before removing the spring.

It is a good idea to also replace the rubber spring seats, which are available in different thicknesses to correct uneven ride heights when carrying the normal load.
Ah right thanks Mike i didn't think of that, makes sense. I didn't know you could get those pads, most people seem to just use the existing ones.

Bumpa
Joined: Fri 23 Jun, 2017 21:31
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Re: Rear spring removal

Post by Bumpa » Tue 18 Feb, 2020 09:41

Grrr. Don't talk to me about broken springs! My 2.2 Sport has broken one rear, and now one front and the broken front spring went straight through the tyre wall - nearly new tyre!

Anyway, the issue is that nobody, not even BMW, can supply the 15mm shorter springs that Sport models use. My local dealer tells me the car is "too old". My Sport is now riding on standard length springs at the rear, and has been off the road for a month while I try to find genuine Sport springs, but to no avail. I reckon I shall have to resort to standard length springs all round.

The question is why do cars now break so many springs? My Ford Mondeo broke three, my VW Touran has broken three, and now the Z3 has broken two. And yet in over 50 years motoring I had never heard of a broken coil spring until about 10 years ago. My friendly garage man reckons it is the commonest repair his workshop now performs.

By the way Mike, who supplies the thicker spring pads?

Mike Fishwick
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Re: Rear spring removal

Post by Mike Fishwick » Tue 18 Feb, 2020 10:13

The current rate of spring fractures is probably due to the use of poor-quality and badly heat treated material, and the craze in the UK for speed bumps. Many springs which are supplied with dampers are of really poor quality, and will split along the coil for 2 to 3 inches, broken springs now being a very common cause of MoT failures.

My 1998 Z3 rides on Eibach front (-20 mm) and standard rear springs (to maintain a sensible ground clearance) without problem in 130,000 miles, while my Golf TDI has now covered 236,000 miles on Eibach springs. The Z3 uses Bilstien dampers, and the Golf has Koni, both of which are firmer than standard, and so reduce the rate at which the springs are compressed.

My advice is to treat speed humps with respect (particularly the short duration plastic type found in supermarkets etc) and fit firmer dampers with Eibach springs all round - but get some of their OE spec springs for the rear, unless you value fashion over practicality!
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dazthephot
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Re: Rear spring removal

Post by dazthephot » Wed 19 Feb, 2020 20:51

I managed to get some Sachs springs for £57 each on offer. I’ll be sure to report if they don’t last. Standard height for my 1.9


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Mike Fishwick
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Re: Rear spring removal

Post by Mike Fishwick » Thu 20 Feb, 2020 09:31

Another factor in spring life is the growth of potholes in UK roads! I forgot to mention that, as the French do decent surfacing, which does not melt in summer, or fall to pieces in winter - with extreme temperatures of minus 10 to plus 40 in my area.
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dazthephot
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Re: Rear spring removal

Post by dazthephot » Fri 21 Feb, 2020 15:34

Managed to do the springs today, actually easier than I thought. Only a little bit of prying required to get the broken one and other one out then a bit of a shove and a little prying to get the new ones in.

In the spirit of sharing here’s the old one next to the new one. Look how thin the old ones are at the top and bottom compared to the new Sachs one. Surely they can’t be original BMW ones?

ImageImageImage


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Bumpa
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Re: Rear spring removal

Post by Bumpa » Fri 21 Feb, 2020 18:16

Yes they are original. That thinning of the coil at the ends is the bit that aftermarket manufacturers can't copy. The thinner section is intended to give a softer initial response until the main spring comes into play.

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dazthephot
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Re: Rear spring removal

Post by dazthephot » Fri 21 Feb, 2020 19:09

Ah right I see thanks. I’m so conscious of bloody potholes and drain depressions in the road but unfortunately er indoors isn’t!! She seems to drive close to the curb rather than in the centre of the lane so we shall see how long these springs last.
Mind you I’ve owned this car 13 years and they’re the first springs I’ve had to do.


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