Variocam rebuild part numbers?

I'm trying to rebuild my early 1999 996.1 (5-chain) variocam actuators, and received a seals kit from Hartage. In disassembling the thing I lost the spring under the piston. The spring an piston are illustrated on page 15-135 of th 996 Engine factory service manual (below) but none of these individual parts seem noted in the "996 Katalog" parts document. Does anyone know of or have the part nos for the plunger (#3) or the spring (#4)? I've been googlin' for hours. Similarly, I was hoping to find an exploded diagram of these actuators which illustrates which exact seals go in which positions. Hartage has a pdf they share with the kit, but I'd like to see an actual diagram from Porsche if that exists. Has anyone seen something like this? (I know they're intended to be replaced not disassembled, and that this a very difficult job... please don't point that out)

Those parts are not availible, never have been availible....I used to have a few old ones I sold/gave parts off of when people lost a spring or something, but now that they can be rebuilt they are too valuable to "part-.out"........You may have to find the ones you lost........Good Luck !!!

Ill have to dig but i should still have a old(bad) one lin a box that i will never need. Lmk.

I did not know it is rebuidable ...

A bit off topic, but do you have a guide for Variocam rebuild? Also does this means you don't have to buy news ones if your cam deviation is out of whack?

The variocam actuator either works or it doesnt. Its not adjustable so its on or off. The cam deviations being out of spec is caused by wear on the pads and chains. The rebuild kit means u dont have to buy a $1100 actuator if it fails but u may have to do all the other work for fix the deviations.

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Thank you for the info, that helps a lot. I presume I would be getting a code if the Variocam actuator was not working?

Contact Lee Jenkins at Hartage for the rebuild instructions and (�125) bag of replacement seals. I'd won't post his document here unless he blesses that. The orings inside them can disintegrate and be injested by the small plunger - one or more of the seals was chewed to pieces, causing the whole thing to bind up. In my case that's what happened on track, and my car threw a dozen codes about misfires and cam position. Orings aren't able to last 25 years, so its really not a surprise... some of them were very brittle. Also, getting these things apart without damaging the aluminum bodies / inner sealing surfaces is a challenge. De Jeeper, if you've got a spring that you'd part with, PM me please & thanks.

De Jeeper sent me a spring from his boneyard and we're back in business. I measured the spring and will try to recommend an equivalent part here for "the greater good" of the community. Spring ends are "closed and ground" so they won't erode the seats when installed. It doesn't seem to be stainless, so I'm guessing "music wire" which is fatique resistant. thespringstore.com PART NUMBER: PC020-219-8000-MW-0570-CG-N-IN https://www.thespringstore.com/pc020...0-cg-n-in.html If any mechanical engineer wants to tell me why I'm wrong, I'd happily take the correction.

Glad it made it to u. Dont see why that spring u linked wont work. And i and a ME too so my opinion counts

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If you have means to measure the length of the spring when it carries a known weight you can calculate the spring stiffness and input that instead of making an assumption regarding the material and find an even closer match to the factory spring. Edit: Thanks for sharing the spring data!

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would you care to share how you removed the plunger past the large retaining ring? I�m battling a variocam issue seems identical to yours and I�d like to inspect those seals. Thank you

Bob, I wrecked one of my actuators while learning. I bought a spare off eBay and rebuilt that one instead once I�d figured it out. Try putting it back together and repeating the disassembly till you�re more comfortable with it. I pushed the piston down about 1/8 inch past the circlip, and pushed the clip straight down with a flat blade screw driver (touching only the clip), then rotating it to a position behind the clip, and let the clip spring force slide it back up but over the screwdriver. See below: Piston position Push clip down, then rotate screwdriver & lay flat against aluminum. Don�t let its sharp corner dig into the wall.

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does the inside plunger that the wear pad snaps on just slide out? Mine seems stuck and I�m afraid to put it in the press.

Hartech has a pdf which shows this rebuild.

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I have had 0 luck finding any information, reached out to slacker racing who sells their rebuild kits with no return response. It�s crazy that there is literally no info online about this

Bob, You're right that there isn't much information online about this repair. I labored over finding info. I reached out just now to Lee at Hartage and asked for permission to share that file here. attached. If he says no, i'll come back and delete it. Sometimes its easier to get forgiveness than permission.

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I actually got it apart in a similar manner. I used a small puller to remove the foot rather than drive the pin out. I managed to get it though

Hello, I'm looking for the measurements of the o-rings. Original or from the repair kit. I'm leaving on the island and deliveries take very long, and really want to check if the local hydraulics supply has what i need. If anyone could measure the o-rings from their repair kit or direct me towards where they might have been already posted - that would be much appreciated.

I'm also in the process of trying to rebuild my actuators, and I wanted to throw out a few comments, and ask a few questions. History (just for color): So I had gotten the actuator/camshaft assembly off of the head and onto the bench. Some wiggling and I was able to get the chain over the actuator and remove it from the assembly. I then removed Porsche special tool #9632. So now the unit is free. At this point the brown piston, spring, guide rod (Part A) seen below will basically fall out. So I set that aside somewhere safe. This is where we get into some of the unclarity (for me) in the Hartech instructions. (In fairness, once you've done it the instructions make way more sense). So it says "remove the pressed in rail slide with a drift whilst supporting the body(small bearing puller works good)." It helps to realize is that the image below shows two parts that are an interference fit, and have been pressed together. In the instructions it shows a fairly tiny hammer, I ended up needing to use a punch and a 5 lb sledge. Others have reported using a gear puller, and I'm sure that a press of any type if you could support the housing would work well. I'll be honest, I was uncomfortable hitting it as had as i needed to, though the most difficult part was finding a way to support the unit without crushing or interfering with anything. The point that was most unclear to me was that (and t his is obvious in retrospect), you need some way to keep the "foot" portion of the assembly away from the housing so you can press the foot off. They mention a "small bearing puller", but not I think, being used "as" a puller, just as something to wedge between the body and foot. Since I'm lazy I just printed some spacers to put in there. (This would probably have been more effective if they were steel, or some non-forgiving material that would transfer the shock better, but it is what it is. To visualize, what hartech mentions, and what I ended up doing looked something like this: The black parts are the spacers that let you drive the cylinder off of the foot. (All of this was step one in the instructions) So step 2 says "press the rail slide that you just removed to its furthest position down or extended." None of these parts are spring loaded or really easily movable (except for the center cylinder), everything is pressed in. So when they say that here, do they mean "hydraulic press" until it gets stuck somehow? Or do they mean (really) "support the black sliding arm thingy"? (The top ring in the image below) As a related images, we see the top of the actuator like this: So we're doing this real time, hence all the edits. A little deeper into this, C/D appear to be a single assembly. I assume that using either surface (c or d) would be similarly functional, but from an ease of user perspective, I used a 24mm chromium deep well socket (Kobalt brand if it matters, either way outer diameter was 32.2 mm) I was hesitant to throw it on the press, so I thought I'd use my bench vise first to determine if that is even what I should be pressing on.(spoiler: it is). So with actuator in vise (horizontal between jaws), and socket fitted against surface C, I tried to see if it would move and had zero success (even with an extension on my vise handle. So i gave up and replaced the bank1 fuel injectors, but i digress. So thinking about it I didn't like the fact that the black cylinder extends so far, down so I whipped up a little piece that should just be a little taller than the black cylinder, but flush every where else (when the piston is fully out) . The only thing this really did was make me feel better about putting pressure on there and hopefully protecting that bit a little. Now the magic sauce... I threw the entire assembly in the freeze for about an hour while I switched injectors and cleaned sealant off the heads mating surfaces. When it had cooled as much as it was going to (and with my new ABS spacer), I took it back out to the vise with the socket. At this point, I didn't even need to grab my handle extension, the vise provided sufficient for to slide that cylinder down a fair amount. The water droplets on the unit are from the condensation because you know, it's August in Alabama. You should be able to see in the image above (the orange highlighted area) the distance between cylinder and the retaining clip as well as the gap in the clip. I've given it a cursory inspection, and will need to dig back into the other posts to see how that clip was removed. will update again once I get the clip out and the piston removed. ...This circlip is the devil.

No wonder the success rate is low. I would just send it to them and pay the $600.

The cost is seals (for both banks) is $200 so you're most of the way there for paying them to do it. I didn't want to pull them both, and then send them out and wait for the turn around, that was really the big turn off for me. If they had some sort of core/replacement thing going on, I would probably have gone that route.

I think they do now have a core exchange program ... I have a set of 2 actuators (used less than 10k miles) I was going to list for sale.

Is the rebuild service $600 each or $600 for both ??? IMHO instructions for something like this leads to more confusion...There are many ways to do simple mechanical tasks, that you have to pick a procedure out of many ways to do it, or write all the ways and have the person pick the one he likes most.... I have Trained many helpers and Techs, and was a Judge for VICA Contests for 7 years ( Vocational Industrial Clubs of America ) ...I can tell you that writing simple and concise instructions that don't lead to confusion is a PITA .... I would love to do a Social Experiment to have many people write instructions for something simple like putting a worm gear clamp on a radiator hose and see how many different instructions are provided and how detailed or confusing some can be ....lol Porsche Workshop Instructions are a good example of being so detailed they are confusing....( sometimes written like everyone is a 5 year old...lol)

I actually thought it was $500 for both sides (5 or 600, i did check and it was both... ok website list 575,. so yeah 600 it is). So totally worth it if you're willing to disassemble, ship them off, and get them back in a couple of weeks) The cost of the seals alone was (if memory serves) $213 USD done as an international money transfer. (no paypal, visa, etc etc). If I were going to do it again, I'd absolutely just ship them off to slakker and have them deal with it and just accept the fact that i'd have everything apart for a few weeks. I'm going to disagree with having instructions for something like this though, I'd always rather have too many versions of the process written from different perspectives, than not enough. In this instance there are basically the Hartech instructions, and various posts that shine a little more light on each part of the process. The hartech instructions cover the basic process, *if* you've already done it/seen it being done. For instance, if you don't already know that the "foot" is pressed on, and it needs to come off, then the directions don't make a whole lot of sense. The second you see what the outcome is supposed to be, those directions become very clear. If you're coming in as a "regular" person, having some additional details that really clarify the pre and post step state (before step1, after step 1), I think that's what really makes that accessible. As far as social experiments go, aren't we already living that?

You know, for $600 to rebuild two actuators, I would just send it to them and be assured that it works.

Does anyone know if there is a good test procedure to determine what if anything in the variocam system is bad? I have my bank one unit out of the car with 220k miles on it. I pulled the cams due to code P1531. My solenoid moves under 12 volts so it seems good, but I have a (original) chain pad that has a chunk missing and is very thin elsewhere. I am hesitant to pull the seals from the actuator without testing the unit first but obviously don't want to need to pull the cams again.

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You can put some tie-straps around the actuators so they don't blow apart and bench test them with air-pressure while applying 12v to the solenoid to see if they actually function... But with 25+ years on them I would recommend to go ahead and rebuild them with new O-rings even if they bench test "perfect" ...

So anyone have luck getting that circlip out? I read the thing about using a flathead but can't seem to get even close

The trick is to push the piston "down" that is next to the circlip, then remove the circlip......The piston has the circlip "locked" into the groove..

Yes. There are dedicated codes for this. When the solenoid fails, you�ll get a P1530 or P1531 depending on which bank has the failure.

Thanks for all the advice on this. I got the circlip out this evening using a hooked pick and a screw driver. I found bracing the pick against one end of the circlip and prying at the other to be effective. Now for my newest concern: I left some small scratches in the actuator body pictured below... Are these likely to be a major problem and if so will it be fine to just smooth them out with fine grit sand paper?

Not a problem...the scratches are above the circlip groove, just smooth them out with a really fine sandpaper..

Thanks again to everyone who has replied with tips. I recieved my kit from hartech today and I am confused by the number of seals provided (15). I identified 4 seals on the outside of the part shown in this attachment and replaced them. I understand there are enough seals for both banks, but why do I have an odd number and where do the other seals go? 3 unused seal types 4 seals changed already

My actuator is rebuilt now but I am noticing the new wear pads fit on really loose compared to the old ones (they wobble around freely on their mating surface) Is this normal? As for my previous question I contacted hartech and got answers. Turns out they send an extra seal due to variations in the part design and we are to match the old seal. I also had a seal that was completely disolved on my unit and there is an O ring I did not see under the hard brown seal.

The loose pads r fine. Thats how mine went back together

The kind people at Hartech made a video of the actuator dissassembly. Wish I would have found it before I did the first one but hopefully this helps the next guy You Tube

Well I put everything back together and sure enough P1531 came back after 70miles of driving... The solenoid moved under voltage and I changed all the seals... Also the wire that connects to the solenoid does send power at 3000rpm. What else could it be?

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I don't know what you mean by the wire sends power at 3000 rpm .. ... How are you checking it ??? The power should be there at all times when running.....The DME applies GROUND to the Solenoid to active, BUT it does so at 1200 RPM and then switches off at 5200 rpm ... If you had a failed solenoid you may have burnt the transistor in the DME ...

I measured the voltage across the two pins from the wire that runs to the dme while having a friend rev the engine to around 3000 rpm. I did this on both banks and both behaved around the same. Not sure if there is a better test than this. One thing I noticed taking the actuators apart is that bank 2 seemed to have a lot more spring compression (The loose fitting spring and plate flew out on their own) when I removed the special tool. Any chance a worn out spring would cause this behavior?

Took the cams out again... I think the issue may be the plunger and spring that the solenoid pushes on. I see to remember these falling out on their own on bank 2 but they were really stuck on bank 1 and needed pliers plus a magnet to remove. Should these come out easy?

They should slide out. BTW, it is for this reason that the last 996.1 engine I built got brand new actuators. $1400 each. Having to mess with this job again is not worth the saving.

The plunger seems to have been the issue. I found that after reinstalling it returns to a much higher position when not held down. I am noticing bits of the old decayed actuator o ring showing up in the cylinder that the plunger rides in as I actuate it. This seems to be causing the plunger to stick and not return after the solenoid pin retracts as far as I can tell. Still not sure I can stomach buying a new actuator so I think this one is going back in after I blow some compressed air through

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That whole cylinder body should be put in the parts cleaner tank and cleaned out completely. Should be no pieces of anything left in there. The bore should be brushed with the proper size brush in the cleaner tank while spraying with cleaner. Even maybe some crocus cloth wrapped around a pencil and used to polish/clean up its bore/and the plunger shaft. Then douched with brake clean and blown out complexity. All orifices/ports need to be cleaned and the brake cleaner straw inserted into them and sprayed thru, then compressed air thru them. If the plunger does not go easily all the way in and out find out why and fix it.. jmo

FYI, Ruby advises against using any kind of cleaning products on these units. He recommends only clean oil.

Adding my findings here, following disassembly of bank 2 actuator out of my MY99 3.4k M96.01 with 128k miles. No error codes stored before disassembly but the never changing 3� cam deviation on the durametric (only bank1 has a cam sensor on the M96.01) I don't believe. In addition and responding to post #20, https://rennlist.com/forums/996-foru...l#post20167198 by @jpholder (thanks for your pointers!) After removal from between the cam shafts, the lower chain guide can be pulled out and with it the piston, a plastic pin and the coil spring. Unbolting the T25 torx screws and removing the solenoid reveals the piston/plunger and return coil spring. Pic shows orientation and order of parts inside the aluminium body. Now, the pdf by Hartech mentions putting some (metal) spacers between the steel plate and body in order to punch the center (which is basically piston assembly) out of it. The picture shows it halfway done: When free and plate removed, this is what you'll see: Turning the body upside-down, you'll see this: This 'disk' (Hartech calls it 'top of the unit') sits on top of the snapring which needs to be removed to get to all the o-rings. The disk is swaged at 4 sides against the aluminium body and cannot be pulled out towards you, hence knocking it further in, past the snapring. Using a socket/tube and a big hammer you knock it further down into the body untill it clears the snapring and exposes it. This requires some proper blows and as such I recommend a press, if available. An uncovered snapring is what you're trying to achieve: Up close: Up to this stage is all basically the same as what jpholder wrote in his post bar some close-ups. Now the finicky part, removing the snapring. This is how I got hold of it: -prevent it from turning, then wedge a thin, flat bladed between snapring and body. -stick a dental pick or similar between ring and ring seat, so it won't snap back into its seat should the blade slip away. The snapring is of quite low tension once you're behind it and can then be easily levered out. Pic below shows the body turned around yet again and the piston assembly pushed in for it to exit the body from the side where the snapring sat. The removed piston assembly together with the disk that was knocked past the snapring looks like this: Disk moved a little further towards end of piston assembly ...and disk completely removed: The above pic convincingly shows that the thick o-ring on the piston assembly (on the piston rod to be exact) merely acts as a bumpstop to avoid metal to metal contact at this end of the piston stroke. It sits very loosely and does not seal against anything. The o-ring on the piston rod on the other side of the piston was stuck inside the body, see pic below. The brown ring of larger diameter is aluminium discolored by engine oil. This o-ring too merely acts as a bumpstop/prevents metal to metal contact as it too sits just loosely around its piston rod and seals against nothing. It is this o-ring that gets hammered to bits at this end of the variocam stroke and these bits are then found in the sump, oil filter or worse, clog up the different orifices and/or perhaps even jam the piston/plunger in pic 2 itself, thereby provoking the specific code mentioned earlier in this thread. In the Hartech pdf this o-ring is missing and also on variocam rebuilds on the 'fun ahead tv' YT channel it's this o-ring. Still from this video below (Can't find the exact video anymore...) The other o-ring, being much thicker, apperently copes with this repetitive load a lot longer, should it ever fail. The swaged disk on my particular variocam actuator has only one single o-ring, whereas the other fotos in this thread and the Hartech pdf show a version with 2. Apparently bank 2 variocam has 1 seal, bank 1 has 2 seals. A word of advice regarding diy'ing the change of the seals. The piston itself has a black seal (probably PTFE with carbon) that seals against the bore in the aluminium body. Underneath it sits what is called an 'energizer' in the shape of yet another viton/fkm o-ring. The engineering term for this kind of seal seems to be 'double acting hydraulic piston seal'. My personal take on these is to NOT replace them if the ptfe seal shows no signs of damage, scratches or tears. Reason being is that removing it will definitely render it damaged and fitting a new ptfe seal is not trivial. Also the risk that the energizer o-ring underneath is the source of green bits of o-ring you've observed, I deem nill. Professional tools for fitting the ptfe seals https://youtu.be/WAaTxO36UkA?is=RNw04ueQaQuxROkb No tool method https://youtu.be/mBmT32C11fU?is=hFXBeOKOJUBjVm2q

Many thanks for this summary – it’s very helpful and informative!

Do you have the dimensions of the O-Rings, is it mentioned somewhere?