Buy

365 GT4 2+2 Shock Rebuild

Discussion in '365 GT4 2+2/400/412' started by samsaprunoff, May 24, 2020.

  1. samsaprunoff

    samsaprunoff F1 Rookie
    Silver Subscribed

    Jun 8, 2004
    3,338
    Edmonton, AB Canada
    Full Name:
    Sam Saprunoff
    Good day Tim,

    Wayne from from Smooth Suspension responded to my e-mail and they also stated that they are not allowed to sell Koni parts.

    It was a good try, but for whatever reason Koni is intent on not supplying their seals, etc outside of their network.

    Cheers,

    Sam
     
  2. To remove this ad click here.

  3. samsaprunoff

    samsaprunoff F1 Rookie
    Silver Subscribed

    Jun 8, 2004
    3,338
    Edmonton, AB Canada
    Full Name:
    Sam Saprunoff
    Good day Daren,

    So far I have not come across anyone who is Koni "connected". That being said, if Koni is being so particular on their seals, etc then I would not want to put anyone or any firm in an uncomfortable situation. These seals are not so special that they cannot be recreated and/or another style used and so Koni's efforts to restrict the sale of the seals will have no real effort. Selling the basic seals would be a good customer service effort and would go a long way in maintaining brand loyalty. However, it is what it is...

    Cheers,

    Sam
     
  4. Tojo

    Tojo Formula Junior

    Apr 12, 2002
    429
    Sydney
    Full Name:
    Tim
    They're certainly not making it easy for you Sam. Perhaps an appeal to Koni's head office explaining your location and postage issues might find someone with authority and sympathy that can help. Outside of that I'm out of ideas

    Sent from my SM-G935F using FerrariChat.com mobile app
     
  5. samsaprunoff

    samsaprunoff F1 Rookie
    Silver Subscribed

    Jun 8, 2004
    3,338
    Edmonton, AB Canada
    Full Name:
    Sam Saprunoff
    Good day Tim,

    Indeed, it would seem that Koni is trying their best to ensure that any rebuilds are via their authorized rebuild centres. As for contacting them... It is a good thought, but my experience is that it would be pretty tough to reach the person or persons who would understand the situation and/or do something about it. Koni has made their business decision and although I may not agree with it, it is their business and so they can do as they see fit. On my side I will simply continue on the path I am on and try a few solutions to see what works best. As I said, this seal is not overly important and pretty much anything that is close to the size will work fine.

    Thanks again for the suggestion and now after trying various places in the US, Europe, and Australia I can comfortably say that all of these areas are following the Koni corporate decision.

    Cheers,

    Sam
     
  6. samsaprunoff

    samsaprunoff F1 Rookie
    Silver Subscribed

    Jun 8, 2004
    3,338
    Edmonton, AB Canada
    Full Name:
    Sam Saprunoff
    Good day All,

    Just a quick update...

    It has taken a while for the rebuild, as I have been very busy with work and also a number of other projects for a few friends. That being said, as I would get tired of my other duties I would spend some time on the shock rebuild. Overall the shock rebuild is very straightforward, but it did take a bunch of work to sort through the seals, etc needed for the rebuild. The shock has three primary seals:

    1. a delrin/plastic-ish dust seal at the very top to keep debris and water out

    2. a compressed seal back below the dust seal. This seal pack is used to keep the shock oil from pushing out along the shock shaft during an upward stroke. It is this seal pack that breaks down over time causing little bits of rubber to fill up the various oil passageways within the shock assembly. Little bits of crap on their own are not good, but under hydraulic pressure these little bits form larger bits and eventually completely plug the passageways and/or affect the internal hydraulic valves that actually define the shocks functionality.

    3. an rubber lip seal between the outer pin nut and shock internal assembly. This seal does not experience the same pressure as the the (2) seal pack and so some liberties can be taken for a replacement.

    The most important seal is (2) the seal pack and a fellow fchat member (Peter) was kind enough to find and source a compatible seal pack that can be used. As mentioned in my earlier posts, Koni and their rebuild centres will not sell any of the seals, etc and so one is on your own. I will post the seal pack part numbers in a later post. For my rebuild seal (1) was fine to be reused and all that was needed was a simply cleaning. Seal (3) was challenging and although I could reuse the originals (I was careful when removing them), I decided not to ... and this was a good thing, as I discovered an oddity with these seals. I struck out finding an exact replacement, as the original seal is somewhat uncommon, as it has a tapered edge, etc (see an earlier post for a picture). Having looked at what it was doing, etc I decided to use a simple O-ring of the appropriate size. This worked perfectly and was a relief that I could actually continue with the rebuild.

    I cleaned all of the internals using relatively passive cleaning agents, as I did not want to use an aggressive cleaner for fear of affecting the internal metal finishes. I used an ultrasonic cleaner with plain old soap and then air-dried the parts. Care must be taken with the parts, as flash rust will appear relatively quickly. I found this out the hard way and so I had to reclean parts and then soak them in shock oil. Speaking of oil... Our manuals list the shock oil, but this oil is no longer made. I was able to cross this oil to a modern oil and it turns out that regular motorcycle "10W Fork Oil" is the replacement. One could use Hydraulic AW32 oil as an alternative, which is cheaper, but fork oil has additives that minimize foaming... as a motorcycle front forks would be bouncing around causing the liquid to foam. Fork oil is really common at pretty much any Motorcycle chop and I used a synthetic version in a 10 Weight.

    I did some testing before I did the final assembly just in case I made a mistake, etc. It turns out that this was an excellent idea, as I had some issues which took time to figure out what was happening. During my test my shock would work as expected for a few strokes and then it would stop dampening. At first I thought it was how I was refilling the shock, etc. What complicated things was the owner's manual stated shock oil volume was way off. I measured the oil when I took it apart and there was a huge discrepancy... The manual says 350ml and I only had about 240ml or so. If I put the 350ml in the oil would overflow... Anyway, I contacted Peter to see what his shocks had for volume (he has a 308 GT4 and so his shocks are a different part) and he also described how he filled his shocks. I tried his approach and the same issue was happening. So... I now had to spend some time to analyze how the Koni shocked worked so I could figure out what was happening. So... testing and experimenting ensued and in the end I found the issue and now I fully understand how these shocks work. I have to say that Koni's design is very ingenious. The shock contains three (3) mechanical valves that control fluid flow depending upon an upward or downward stroke. The first valve is located on the bottom of the shaft and is comprised of a circular washer-spring and a washer that covers a series of holes in piston. The two other valves are located at the bottom of the shock tube and these are located in what is called the "foot" valve. The valves only allow passage of fluid in one direction. These valves control the fluid flow and the way they are setup allow the system to self-bleed, etc. Secondly, all of these valves are mechanical and so unless a lot of water gets into the shock cavity, these valves do not wear. As for the shocks adjustability... this is also interesting. On the bottom of the piston is a toothed nut that when rotated exposes or closes a number of holes that are passageways for oil to flow back through the shock shaft and bypass the piston's valve. All in a all a very elegant design.

    Now, what was happening me to was that I was unaware that there was a covered cavity on the top of the foot valve. I simply thought that the spring covered washer was covering the foot valve's holes, but in fact this was not the case. It seemed that all of my cleaning could not remove the bits of compressed gunk in this cavity and so as I was testing the shock bits of this gunk would cause the valve to remain open... and so the valve could not do its job. Once I discovered this I used some very fine tools and cleaned out the cavity and the shock worked as it was supposed to. Now that this was done I then repainted all of the shock bits. I decided to press in the bushings before painting (and then mask them), as I figured the press would mar the fresh paint. As for the paint... Others had been told by Koni that PlastiKote T-31 (General Purpose Bright Orange Premium Enamel) is what they now use. This paint is a close match to the original paint (a bit more red in the orange) on my shocks and so I used it. It is an enamel based paint and so prep and multiple coats are needed.

    After painting a few coats (must wait 36 hours before recoating) and some light tough ups I started the final reassembly today...Below is a picture of the front and rear shocks as they are now. and they are now fully assembled. I just need to apply the winged decals and mount the springs and this project will be complete.

    As I said I will post again with part numbers along with more pictures.

    Cheers,

    Sam

    Image Unavailable, Please Login
     
    red27, raemin and Schumi like this.
  7. To remove this ad click here.

  8. samsaprunoff

    samsaprunoff F1 Rookie
    Silver Subscribed

    Jun 8, 2004
    3,338
    Edmonton, AB Canada
    Full Name:
    Sam Saprunoff
    Good day All,

    Sadly, not a lot of progress on the 365. However, some progress has been made and so I will be posting a bit over the next few weeks. I finished applying the winged decals to the shocks and they turned out great. My originals were winged and not the "triangle" style that Koni used later. I found two ebay sellers that had the winged decals where one was a "wet-set" type and the other a vinyl cut type. The "wet-set" claimed to be like the originals and so I went with it. Application was straightforward in that you soak the decal in water until the decal releases from the backing. Then very carefully place onto the shock and lightly smooth out any wrinkles with a paper towel. Again, do this carefully, otherwise you risk tearing the decal. After the decal dried I applied a light coat of clear on top... ensure you test the clear with your base paint first to ensure compatibility... otherwise the solvents in the clear could wrinkle/damage the base paint.The placement of the decal was approximately where they were on my originals... although I did shift the position so that the decals were not obscured by the coil spring rubber bases.

    I also cleaned the rubber shock bumpers, as they still had koni factory paint on them. I used carb cleaner, as it was not harmful the to rubber, but would easily remove the old paint... The solvents in the carb cleaner also rejuvenated the rubber itself and they looked great. All that is left is to add the coil springs to the shocks.

    The shock assembly is comprised of the shock, a rubber shock bumper, an upper and lower rubber coil spring base, the coil spring, a top plate and two keepers. The rear shocks are pretty straightforward to assemble in that the shock and parts are simply fed into the coil spring, the coil spring is compressed, and then the top plate and keepers are added. The front shocks are not so straightforward. I say this, as the front shocks have a tapered rubber bumper that does not fit through the upper rubber base/boot... secondly the top plate has a pocket that appears to hold the rubber bumper... thirdly the upper spring boot is tapered near the top and the taper seems to match the rubber bumper's taper. To assemble the parts I have to remove the upper mount then mount the spring, attache the upper plate with the fitted bumper, then reassemble the upper mount, then the keepers. For whatever reason this is the only shock style I have found that needs this to be done. I have attached a few pics to show this and I would be curious if anyone else has any comments on what they did when or if they reassembled their front shocks, etc.

    This week I will mount the coils and will take pics of the spring compressor I have access to.

    Cheers,

    Sam

    Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
     
  9. samsaprunoff

    samsaprunoff F1 Rookie
    Silver Subscribed

    Jun 8, 2004
    3,338
    Edmonton, AB Canada
    Full Name:
    Sam Saprunoff
    Good day All,

    I am finally concluding this thread that I started last year...

    When I posted last, all that was left to do was to mount the springs to the shocks. Sadly, I had a hell of a time mounting the springs. The spring compressor I used to remove the springs (looks like this one: https://www.summitracing.com/parts/otc-6637-st) had issues for remounting. The issues were two fold. The first is that the compressor's "fingers" would start to touch the coils above and below the fingers when the spring is compressed enough. Given that I had my coils powder coated I did not want the finish marred or damaged. The second issue was that there was limited space to insert the keepers along with tightening the top mount lock nut and/or inserting the roll pin. I tried for a few hours and eventually gave up. I tried a number of other spring compressors and I could not seem to find anything that worked to my satisfaction, but also that I felt were safe. What I ended up doing was creating a safety "cage" that surrounded the shock/spring assembly and then compressing the assembly in a hydraulic press. The safety cage was comprised of two steel plates (3/8" steel) laser cut to allow for 4 threaded rods to encase the entire shock/spring assembly. As the hydraulic press compressed the spring I would tighten threaded rod keeper nuts so that the spring was always secured and could not expand if something happened during compression. This worked well and was very safe and allowed for easy and safe access to the spring keepers and installation of the top shock mount. The other benefit was the the hydraulic press provided a consistent vertical force which kept the Spring vertically aligned.

    Designing the plates only took 10-15 minutes and took only minutes to laser cut. The real effort was cutting the threads for the threaded rod (1/2" - NC13). I had to make two plate sets, as the front and rear shock assemblies have different diameters/springs (see pic). The cost to laser cut the plates was about $80 and so not overly expensive. I have had the plates since last Summer, but work duties prevented me from doing anything on my car until recently.

    Hopefully the above information will assist others, as I never thought that compressing and installing the springs would take so much effort... and especially so given the availability and number of commercial coil spring compressors available. In the end a regular Hydraulic press with a custom safety mechanism is what I needed.

    With that said, finally, this sub project is complete and hopefully my next sub-project will be starting soon, which is repainting the frame (with the body attached). Once the frame is painted I can start the "fun" work which is reassembly. I am hoping to have this done this Season, as I really would like to get my car on the road before I get too old to enjoy it :)

    Cheers,

    Sam

    Image Unavailable, Please Login
     
    raemin and Al Campbell like this.
  10. ricar116

    ricar116 Formula Junior

    Aug 2, 2005
    396
    Bolivar, Missouri
    Full Name:
    Rick Carr
    Sam,

    Thank You!
     
  11. samsaprunoff

    samsaprunoff F1 Rookie
    Silver Subscribed

    Jun 8, 2004
    3,338
    Edmonton, AB Canada
    Full Name:
    Sam Saprunoff
    Good day Rick and everyone who liked my thread,

    You are all most welcome!

    If anyone has any questions, etc on the shocks, how they work, or what I did by all means ask.

    The only thing I would have done differently would have been to powder coat the shocks as opposed to painting them. The enamel paint is perfectly fine, but is not nearly as robust as powder coating. In my case if I wanted my rear shocks to match my load levellers I had to paint them... For those that are using coil overs, etc then powder coating would be my recommendation.

    Cheers,

    Sam
     
  12. To remove this ad click here.

Share This Page