Marzocchi rear shock servicing

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Marzocchi rear shock servicing

Postby Gary D » 08 Oct 2017 19:18

Hi

I've also posted this on the 500 forum, but I'm posting here again in an attempt to gain greater viewing.


I could use some assistance with refurbishing the rear suspension on my Sport? Can my Marzocchi rear shocks be serviced & does anyone know if the seals are available & if so, where can I find some? Does anyone know the correct grade of damping fluid?

Lastly, has anyone stripped the black coating off the springs & refinished them? Are replacement springs available? I'd appreciate any help on how to go about all of this? I'd like to retain the Marzocchi's if at all possible, even though it maybe cheaper to go the Hagon route.

Many thanks,

Gary
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Re: Marzocchi rear shock servicing

Postby MickeyMoto » 09 Oct 2017 07:00

Marzocchi have gone belly up. Have you asked Hagon if they will service them? There used to be a company on the South coast who did the seals, but can't find them.
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Re: Marzocchi rear shock servicing

Postby Ming » 09 Oct 2017 07:06

I have a set to overhaul, too. I have found info here: http://www.laverdaforum.com/forum/index ... ic=89947.0, here: https://www.ducatimeccanica.com/marzocchi1.html and here: http://www.suspensionzana.com/index.php ... Itemid=114.
I haven't found how to remove the top nut (of the damper) yet - it is quite slim and appears to be fairly soft, so I think a 'special tool' may be needed. You also need to be able to compress the spring in order to remove the collet.
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Re: Marzocchi rear shock servicing

Postby texaskitty » 09 Oct 2017 08:28

See my reply in the 500 part of this forum but ..... the early 350 shocks (roughly 1974/75 to 1977??? give or take a year) had quite a slim nut which was easy to damage; I went to the trouble of getting someone to make a spanner/tool specifically for this nut. I wanted a spanner/tool that would not slip and stuff up the corners of the nut.

The nut on my 500 was quite different. The top of the nut, immediately to the inside of the hex of the nut, is peened over six or so times, holding in place a washer which in turn secures the small seal that fits around the chromed shaft. Below the hex, there is an O-ring at the top of the nut's thread. New nuts (including the washer, the small seal under the washer, and the O-ring) were part of the rebuild kit for the 500 shocks, so it didn't matter if the old nut got damaged on removal.

If you get the nut off be careful, slow and deliberate as you pull the shaft out of the body and note where everything fits.
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Re: Marzocchi rear shock servicing

Postby davel182 » 10 Oct 2017 07:52

Here is a link to the "Marzocchi A 73 / Euro 74 service manual".
http://web.tiscali.it/lmg/MARZOCCHI_A73_EURO74_MANUAL.pdf

The shocks on mine are like the Euro 74 model and, as texaskitty has pointed out, one of the problems is the crimped nut (19 - Boccola di guida / Pilot boss) which the manual states is supplied as a unit because it is not possible to replace the seal. It IS possible but it requires care and I doubt it would work more than once because the metal is so soft and the crimps just break off.

There is an article somewhere (but I can't find it now!) with an elegant solution showing how to adapt the nut with a plate and 3 tiny screws so that the seal can be replaced (like the A 73 model) but I don't have the equipment or experience to do the job anyway.

I did ask NLM about Marzocchi parts but they replied they'd given up on that in favor of Hagon units.

There's also quite a lot about this era of Marzocchi shocks on forum.bevelheaven.com .

The picture in Ming's suspensionzana link marked "KIT euro 10,00 mm" contains the boss but unfortunately mine were 9mm and that is not listed.
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Re: Marzocchi rear shock servicing

Postby Bison » 18 Oct 2017 12:55

I had very hard springs on my remote reservoir Marzocchis, number 4 if I remember, replaced them with Enfield ones, fitted straight on, and are spot on for my 72Kg weight and 3 1/2 sport. I should mention they were not in the least expensive!.
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Re: Marzocchi rear shock servicing

Postby Gary D » 22 Oct 2017 12:37

Afternoon all

Just to confirm that with your assistance I've secured a shock service kit for the Marzocchi's. Suspensionzana are the people to deal with & Ugo Zanardini was the kind gentleman who helped me out. Just make sure you send a pic of your particular shock & measure the rod..mine was a 9mm & they had the kit in stock.

Any recommendations for some good spring compressors & shock oil please?

Thanks again for everyone's assistance.

Cheers, Gary
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Re: Marzocchi rear shock servicing

Postby texaskitty » 22 Oct 2017 14:43

I have never had a spring compressor, unfortunately. I have used a couple of old car tyre levers placed through the spring near the top, and another pair of hands to hold the levers and compress the spring while I remove the retainers at the top. (If you do this you might want to use something to protect newly refinished springs and shock body.) It's so long ago that I rebuilt a shock absorber that I can't really do any recommending on the fluid.
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Re: Marzocchi rear shock servicing

Postby Steve Brown » 22 Oct 2017 14:51

Hi Gary, glad you found the kits! Ref the oil, I'd guess at a fork oil of anything from 5W to 15W depending on how much damping you like. I did do some 30 odd years ago and found I couldn't detect any difference using different oils. I may not have had so many choices as now though...
Btw, did you need to speak Italian to deal with the supplier?
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Re: Marzocchi rear shock servicing

Postby MickeyMoto » 22 Oct 2017 17:20

I have seen tie straps used to compress springs. The strap should be kind to the spring. Probably need good quality straps to prevent slippage.
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Re: Marzocchi rear shock servicing

Postby P&S » 22 Oct 2017 21:44

davel182 wrote:Here is a link to the "Marzocchi A 73 / Euro 74 service manual".
http://web.tiscali.it/lmg/MARZOCCHI_A73_EURO74_MANUAL.pdf

The shocks on mine are like the Euro 74 model and, as texaskitty has pointed out, one of the problems is the crimped nut (19 - Boccola di guida / Pilot boss) which the manual states is supplied as a unit because it is not possible to replace the seal. It IS possible but it requires care and I doubt it would work more than once because the metal is so soft and the crimps just break off.

There is an article somewhere (but I can't find it now!) with an elegant solution showing how to adapt the nut with a plate and 3 tiny screws so that the seal can be replaced (like the A 73 model) but I don't have the equipment or experience to do the job anyway.

I did ask NLM about Marzocchi parts but they replied they'd given up on that in favor of Hagon units.

There's also quite a lot about this era of Marzocchi shocks on forum.bevelheaven.com .

The picture in Ming's suspensionzana link marked "KIT euro 10,00 mm" contains the boss but unfortunately mine were 9mm and that is not listed.


Hello, I am new in the forum.
You mentioned an article about marzocchi shock absorbers (thank you for "elegant"). Is in the Morini club Roma forum.
http://motomoriniclub.forumcommunity.net/?t=56189893
I show there also how I managed to compress the spring to release the spring retainer with no tools.
Suspensionzana has also the 9 mm. kit. I bought mine there.
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Re: Marzocchi rear shock servicing

Postby davel182 » 23 Oct 2017 12:24

Hi Paolo

Welcome to the forum and thankyou very much for the link and the information that 9mm kits are available.

Maybe it's my browser but the link just presents a blank page. However I have now got the article from Google's cache and saved it to my local disc. And it IS elegant (in my opinion anyway) - I wish I had the experience and equipment to do something like that.

Best wishes.

Dave
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Re: Marzocchi rear shock servicing

Postby P&S » 23 Oct 2017 13:57

Thank you again for your compliments.
I am glad I've been of some help.
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Re: Marzocchi rear shock servicing

Postby Gary D » 23 Oct 2017 21:37

Hi all

Thank you all for your thoughts & shock servicing information. My laser cutting pal may come in useful in concocting that spring compressor! Steve, no Italian language was necessary & the service was outstanding. Ugo is a knowledgeable & nice guy & the prices are pretty reasonable given the rarity. I'll post again once this job is firmly under way.

Cheers

Gary
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