OEM Coil Springs

[RussGLAuto]

Afternoon gents,

I'm looking to replace shocks and coil springs for as close to OEM as possible. I'm baffled however as to what the different colour paint marks mean on the linked diagram. Are they different strength springs?

https://volkswagen.7zap.com/en/rdw/scir ... 11-411010/

Suffice to say, no colour left on what look like originals fitted to Gladys...

Pop quiz: which do I need for a 1983 GL, or doesn't in matter any more?

Thanks

Russ

[GT_II]

Hi Russ

The colour markings on the original springs depend on the engine fitted and possibly also optional equipment such as aircon, etc. The VW Service Manual covering Running Gear applicable to Mk1 and Mk2 Sciroccos published in 1985 contains a cross-reference table, but unfortunately the shading to show which engines were fitted with which springs are not legible on the current electronic copies. I have checked both the German and English editions. If you are lucky enough to locate a hard copy of the service manual you would get your answer.

The table structure does, however, give a flavour of how the colour codes were applied. It seems that the springs coming out of the factory may have been more finely tuned to the individual car than service replacements. However, without the shading, it is difficult to make much sense from the table:

Scirocco 1979 on front spring colours.jpg

The table for rear springs is a lot simpler, as there is less choice. Again, it seems there may have a degree of fine tuning of springs to the car in the factory, but not for spare parts:

Scirocco rear spring colours.jpg

For what it's worth, my 1992 GT II has the original front springs with 3 blue stripes and I plan to replace them with Bilstein B3 36-131105 springs which VW Classic Parts supply as OEM equivalent to 171411105G953. For the rears, I plan to use Bilstein B3 36-155095, which VW Classic Parts supply as OEM equivalent to 531511105A952.

[WreckTangle]

I’ll put in my two-penneth that it probably doesn’t matter too much now, especially if using secondhand springs which will likely be some way off original spec. When I replaced the previous owner’s eBay coilovers on my 1992 GT2 I used the front struts off a GTX that my local scrappy just happened to have in at the time. I have been pleased with how they have performed, following a complete strip-down, powder coating and new strut inserts. Even if they aren’t 100% correct they are miles better than the coilovers. Plus they were just down the road and cheap.

[RussGLAuto]

Thank you both gents for the input.

GT_II - great you found the original allocations. On the rear spring attachment you can just make out the shading. For early 1.6 models looks like Yellow, for later chassis numbers it's blue which of course matches what you found. That said, no one differentiates today... I think I'll go with your choice though so thanks for the steer.

Now, next question, difference between gas and oil filled struts? Yes, I know, one has oil... I mean ride difference?

I was looking at this set from VW Classic:
https://www.classic-vw.co.uk/front--rea ... 4263-p.asp

What do you think? Don't seem to have an equivalent part number.

[GT_II]

On the rear spring attachment you can just make out the shading. For early 1.6 models looks like Yellow, for later chassis numbers it's blue which of course matches what you found.

My reading of the table is that the Scirocco rear springs were all yellow striped, 1, 2 or 3, with replacement parts having 2.

For fronts, my guess is that the original specs were mainly a variable number blue or green stripes, depending on engine and/or trim.

Shocks I haven't looked into, as I don't plan to change mine. I do plan to change the top mounts, VW Classic Parts reproductions for the rear and Bilstein B1 12-244751 on the front.

I am sure the original shocks were oil filled, with air filled being a more recent technology. In terms of ride quality, there isn't necessarily any difference - both are tunable by the manufacturer to whatever damping effect is needed. And apparently both are mainly oil filled, the difference being that air-filled are also pressurised with gas. Which makes them perform more consistently in demanding or high performance applications:

https://www.bilstein-shocks.co.uk/blogs ... t-with-gas

[WreckTangle]

For shocks I went for Boge oil-filled for originality.

On the front I used Boge 27.229.1 inserts. These fit in your existing strut which you have to open up and drain out the original oil. I found it convenient to obtain the correct gland nut tool. You may be able to get away without this but you run the risk of mangling the nuts and won’t be able to torque them accurately. That said, I wasn’t able to find torque specs for that nut and went for about 50ftlb which felt about right.

On the back I used Boge 27.832.0. I think the ones I got were new old stock, but they still seem to be readily available.

If you’ve not seen it already you might be interested in looking through the thread I started when I did mine. Plenty of helpful advice from others in this too.

https://forum.sciroccoregister.co.uk/vi ... hp?t=21448

[RussGLAuto]

Great gents, appreciate the info!

Got to love that Bilstein website, priced up new (Gas) shocks and springs all round and err... gulp, £464 plus shipping which won't see any change out of a monkey

I better offset them with some riding lessons for her indoors! Not so much a carbon offset as a wife offset...

For the price of new springs at £159 for four, as opposed to shot blasting and powder coating (estimate £100 for 4) I might as well go for new. As I say the originals are quite well corroded - hang on, is that a yellow mark I spy?!!

[RussGLAuto]

Evening chaps,

Hight time I got into the man cave and get spannering on me undercart! Had to purchase a Swann neck ring spanner for the rear suspension tops which were coated in some sort of white gunk. Quite probably never been changed since build in 1982. I have a history receipt from 2012 detailing the changing of the front shocks but nothing for the rears.

Decided to buy a pair of spring compressors from Scewfix for twenty quid. Pleased I did, good quality and helped with the extraction by taking the tension off.

What I am slightly concerned about is the length of the new springs vs the original. A good 2 ½ inches longer. The nicer of coils are the same and I guess that's what 39 years of compression does to a spring, as well as the bushings and bump stop!

[RussGLAuto]

Just wish I could have a nice portable garage lift to get that rear beam dropped, blasted and powder coated... However, Christmas is just around the corner!

Bushings and bump stop also very well compressed compared to the new. Decided to do the rears first because, well, more easy. Inn it!

[mark1gls]

It’s a good idea to coat the bottom bolt for the shock in copper grease or some sort of anti seize as they can rust to the shock and then it’s a nightmare to remove at a later date.

[GT_II]

Hi Russ, I can't really tell from the photo, but are the new rear springs progressive like the old ones, ie with the metal varying in thickness over the length of the spring, thickest in the centre and tapering down towards each end?

The car will probably sit quite high at first, but should gradually settle down with use.

[RussGLAuto]

Hi Russ, I can't really tell from the photo, but are the new rear springs progressive like the old ones, ie with the metal varying in thickness over the length of the spring, thickest in the centre and tapering down towards each end?

The car will probably sit quite high at first, but should gradually settle down with use.

Hi,

Aside from the overall length they appear identical in thickness and number of coils. The shocks are almost identical also aside from a much firmer resistance, takes two hands and several seconds to compress them whereas I can do the same one handed prity quick with the originals.

Great quality from Bilstein! Not the cheapest but then they should last another 40 years... Hopefully this should cure the wallowing handling which was very noticeable over bumps at speed.

I'll take a few more shots after refitting. I thought the same about the ride height, but then if I compress and tighten the top spring retainer as before the unit should in theory be the same height before installing...

[RussGLAuto]

It’s a good idea to coat the bottom bolt for the shock in copper grease or some sort of anti seize as they can rust to the shock and then it’s a nightmare to remove at a later date.

Absolutely, copper lube tube at the ready! Having said that the original bolt and nut came off and out without any swearing at all

Now, here's a question. The two large rubber bushes at the strut top - grease or no grease? Didn't appear to be any when I removed the originals.

Oh, another question, do I keep all this old original kit for provenance or scrap it?

[mark1gls]

No grease or anything on the rubber bushes.

Definitely keep the front strut housing if the new shocks come complete, rears it’s up to you if you want to keep the springs but the shocks sound like they are no use to anyone.

You was lucky with removing the original bottom bolts as lots of people have to cut them off.

[RussGLAuto]

Hi Russ, I can't really tell from the photo, but are the new rear springs progressive like the old ones, ie with the metal varying in thickness over the length of the spring, thickest in the centre and tapering down towards each end?

The car will probably sit quite high at first, but should gradually settle down with use.

Hi,

So had a closer look when refitting today, yes, they are identical to the old with, as you say, progressive thickness. Checked the ride height and with the new they are c. 10-15 mm higher with the replacements. I put this down to top bushing compression over time. Nothing else would make a difference.

I can also confirm what I removed are original to the car from build. Found the VW Audi stamp on the shocks under the rust. Hence I have decided to keep them with the car.



Cheers

Russ