Rear Damper Spring Removal

[Dilkris]

OK - so what's is the secret with spring removal? (I have new adjustable dampers but wish to use the original springs). My spring compressor does not work in this application as there is limited clearance between the spring and shock absorber body for the "claws" of the compressor to safely engage and stay put.
I rigged up my press (with a locating collar at the top for safety) and made some spring "clamps" (see last 2 photo's) so as once the spring was compressed I could fit them, safely keeping everything in that position so as I could remove the top spring retaining collar on the damper unit. Sensible approach? (I thought so) 
It didn't work. 
When I compressed the spring by 4", installed the "clamps" and released the compression on the spring - the top collar was still firmly located as the spring coils inside the dust shield (which are not clamped as access is not possible) simply returned to their uncompressed length.
The easy fix would be to cut off the dust shields and make new and longer spring "clamps" which would span the full length of the compressed spring, but, I am trying to retain the dust shields. (I note however on some members rebuilds that they are not there)
So question are:- a) Am I dong something wrong? and b), Should I just scrap the dust shields? 
         

[BDA]

I'm a little confused by your description. It just seems that your collar is corroded and stuck to the sheet metal cap or is it to the top of the shock? You should be able to pry them apart or maybe use a hammer and a punch to knock them loose.

[Dilkris]

Corrosion is evident between the collar and "sheet metal cap" - (but this is really almost cosmetic), they are "held" together by the force arising from the compression of the spring - if the spring effect was not there - they would simply fall apart.  I am trying to compress the spring and hold it there, (in order to remove the force that holds them together), and withdraw the collar and .... celebrate 
Note: The sheet metal cap (as you refer) appears to be bonded and almost integral with the dust cover.      

[BDA]

I assure you the collar, the cap, and the rubber dust cover are three separate pieces. When you compress the spring, it should allow the three pieces to come apart. You only actually need to compress the spring a couple of inches. That should be enough to get the collar out (the height of the part of the collar you see and about 1/2" that goes down into the cap/cover/spring. The cap is necessary to keep the collar and spring from chewing up the cover.

[BDA]

Ok. I THINK I understand what's going on. The coils exposed from the dust cover are not enough to compress the spring enough to relieve the pressure against the collar. If I got that right, here's how I fixed it. I made a spring compressor from two plates and some threaded rod. The plates have holes in them to fit around the tube of the shock but support the spring perch. The picture I've attached shows the two sizes needed for the stock Armstrong front shock. I can only find those two plates so I think that's all you need but you may need something to make the hole in plate #2 smaller for the rear shock if you catch my drift.

The dimensions aren't at all critical but here are mine (you should make your own measurements to be sure):

plate thickness: 3/16"        (certainly thicker than you need)
threaded rod: 1/2"             (certainly bigger than you need)
hole in plate #1: ~2"
hole in plate #2: 2 5/8"

If I still misunderstand what's going on, my apologies!!! Please try again!

[EuropaTC]

Hi Chris (?  right name ?)
Hmm, let me start off by saying that I wouldn't be reusing those springs, they look well past their sell-by-date and new springs are cheap, shiny and much easier on the scraped knuckles.

But if you really, really want to......

Free length on the TC is 16.75", fitted 9.86" giving roughly 500lb of pre-load. so you've got to compress the coils you can see by at least 7.5" to have half a chance of getting the top coil loose enough to move the collar.

It's so long since I had the OEM damper/spring that my memory is hazy but I think I once made some "hooks" to catch on a coil inside the rubber shield. If you measure the distance between the coils you can see you'll soon tell how many you have to get coil-bound to get enough movement. My standard coil compressors won't go anywhere near some of the OEM Lotus springs so DIY (or chuck it in the bin  ) is the way forward.

Some folks have used webbing with ratchets (the stuff you tie down cars on trailers with) because of course you can thread the webbing through easily enough. Technically it's within the limits, assuming 8" compression then that's 600lb so 2 straps will be well within range.

Brian

[Dilkris]

Many thanks BDA and Europa TC, ("yes" it is Chris), I think I understand the problem now.

My technique to compress the spring has been to compress it with my hydraulic press via the top and bottom mounts of the damper itself; the problem with this is approach is clearly 2 fold:-

1. You have to restrain the compressed spring via clamps in order to remove the effect of the press so as to remove the top collar.
2. Because of the inaccessible spring coils within the dust cover, (which I cannot access to constrain), once the lower coils are clamped and the press removed, sufficient energy still remains in the unconstrained coils hidden by the dust cover to make removal of the top collar impossible.

Compressing the spring in this (incorrect) fashion by just 4” renders the exposed coils almost “coil bound” and is pretty much the limit for being able to fit spring clamps between the coils. (see photo)

The photo of the shock unit with the tape measure, (sorry in metric, but I convert here approx), shows an overall contained spring length of 14”, with 9” of the coils exposed and 5” within the dust cover.

So the solution is therefore to either cut off the dust shield, thereby allowing more compressed coils to be clamped or, to make a spring clamp that compresses the spring ONLY (via the lower mount and the top locating ring) which appears to be what BDA’s spring compressor does – and correctly so.

I take note of Europa TC comment regarding spring condition and yes I can buy new springs, in fact you can buy just about anything for a Europa, (except ash trays… ), but I am retired so whilst money is at a premium time isn’t, (strangely, I also want to rebuild a Europa as opposed to build one). I am using adjustable dampers Europa TC so hopefully any spring settlement can be compensated for. Buying new springs also wouldn’t solve this problem as if I can’t establish a technique to safely get the old springs off – I equally wouldn’t be able to get the new springs on. 

And the dust shields - are they considered really necessary? Are you all running with them?
     
I’ll keep you posted
           

[EuropaTC]

Hi Chris,
I'm intrigued by the measurements on the damper units but it's a while since I had the standard units on so I was taking the numbers from the workshop manual to get an idea about what you were up against.  Now when I think about it, that would be a lot of preload and it got me wondering if the "fitted length" is actually the spring length with the car loaded and on it's wheels. That might make more sense, but to be honest until this morning I'd not thought too much about it.

If you've got adjustable damper seats then getting new springs is even easier because you can just pick something that will "just" fit with the seats at their lowest point, that's what I did anyway.  But I respect your wish to rebuild rather that renew. I'm just lazy y'know....   I couldn't take all that wire brushing !

On the protective covers, I still run them and I also fitted a rubber sleeve over the aluminium threads on the body of the damper to stop the spring rubbing  (it was a mountain bike inner tube I think). 

I'm sure you could do without them, especially considering the reduced mileage the car is likely to do, but I prefer to keep as much grit out of the top seal as possible.

Brian

[BDA]

Speaking of the dust covers, I never questioned what they are really for but thinking about it now, I wonder if they really aren’t an attempt to keep the spring straight so it doesn’t rub on the shock body...  and if that is what they are for, they do not do a very good job. Brian’s inner tube is a good idea (I assume it works). Before I really got going on putting my car together - over 20 years ago - r.d. sold Teflon sheets with glue. You trimmed the Teflon and glued it on the shock tube. So that is what I did. I like Brian’s method better.

I kept my dust covers as well. I think at the time, they were parts that came off the car when I took it apart so I put them back on the car when I put it together.

[Dilkris]

I agree - dust covers and protection on the shock casing necessary. Must admit I like the idea of teflon sheets glued on the shock casings (assuming non adjustable shocks). I used to have a 521 Eclat and the rear "squeaking" generated by the rear springs rubbing on the shock absorber casings used to be tiresome. Notwithstanding this. those threads on the adjustable shocks will benefit from protection. (Inner tubes or similar)   

[BDA]

I have adjustable SPAX shocks. I glued the Teflon on the barrel of the shock above the threaded area.

[Dilkris]

OK - springs now off the dampers. (Looking for a thumbs up emoji but can't find access to one).
Photo shows my new approach;- slit the dust cover to allow access to the hidden spring coils when compressed and made longer spring clamps, (photo shows the shorter "first attempt" spring clamps above the "second attempt" units.)
Photo also shows unrestrained springs as 400mm (15.7") in length, and "yes" dust cover, spring "cap" and collar are as advised on the forum as 3 separate pieces, (they were however pretty much bonded together by sh*t and rust).
Conclusion of this operation for any people about to embark on this operation - "Don't do it this way"   
Refer to BDA's post on the 02.01.21 and do it his way.
Ideally you have to compress the spring ONLY and not use the assembled damper to compress the spring - as I did. (Refer my previous pics in this thread) 
Now onto spring facelift, dust seal replacement/repair plus cover of some kind between spring and adjustable shocks.           

[BDA]

I'm glad you finally got it sorted. I was morning the loss of your dust cover - I think that would be a piece that would be hard to find or duplicate - but I'm not sure it's a great loss. I do think I would look for shorter springs in case the dust cover helped constrain those long springs.

[Dilkris]

The dust cover rubber is severely perished - I cut them carefully in the hope that I could glue and re use them - but I think it fair to say they are "gone"
At least I have a pattern !!!!