I have a 1978 GT4 #14642, and have suspension problems. Does anyone have any experience with the Wilbers units? Thanks.
Ride height seems low. Any sharp bump, like a transition from scraped pavement to old results in a sharp jar, and the car is bottoming out on surfaces that don't seem to unsettle other cars. I saw the Wilbers coil-overs offered when searching for shocks on line. Konis seem to be unavailable, so I was looking for other options. I had not heard of Wilbers for cars before, and was seeking any information I could find.
Im not familiar with Wilbers. I would get the car on a lift to check control arms and bushings etc. Maybe the springs and shocks are done. Dumb question but Do you have enough air in the tires?
I had the Konis for my 400i (42185) rebuilt by a company in Arizona about 2016, and was completely dissatisfied with the result. The car went right down on the bump-stops. I sent them back, and they were returned unimproved. The company refused to offer any compensation. I ended up having Monroe air shocks installed and they performed very well. I sold the car in 2017 and it was resold in 2020 on BaT very successfully, and I think the Monroes were still installed. Wilbers is a German firm with a US distribution, specializing in motorcycles. I was hoping someone on the Forum might have some experience with them. They offer both front and rear coil-overs. Quote was $1493.00 for the rears, complete. Correct Konis for the front are available (best price I've found is $341.00) but not rears. The car has been on a lift, and the control arms and bushing show normal condition. Tires are XWXs, 2020 date codes, factory pressures. Thanks for your comments.
Koni originals are rebuildable, "bottoming out" sounds like the shocks are no longer working. I rebuilt my rear shocks about 15-20 years ago, they were pretty easy to take apart and the valves were full of granular rubber pieces from the degrading seals. I did a thread on it but it was lost with the big server failure shortly there after. It all depends on how your mechanically capable you are, send out to Koni if need be. First photo is of the main parts, bumper, retaining collar, upper bearing/seal and the valve assembly at the end of the shaft. Second: valve assembly at bottom of the shaft Third: holes at the end of the shaft and "adjustment" piece with tangs that engage to valve at the lower end of the inside tube Forth: valve at the bottom of the tube, Fifth: that valve disassembled Koni cutaway Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
So you are thinking that the compression dampening is bottoming the coil? The shocks only have adjustable rebound. But there must be some compression resistance built in when the fluid moves through the emulators then.
It seems that there is a loss of compression dampening for whatever reason. My car would not necessarily bottom but would scrape the road at the front. The shock valves were full of rubber particles from the upper seals which were nothing but rubber washers stacked then compressed by the threaded cap in the upper bearing/seal assembly. Later shocks used a normal oil seal which I converted my shocks to, it requires some machining work. The new style oil seal is illustrated in the cutaway drawing. I don't know when the change over was made. I had a co-worker/friend who left for a job at Koni (rebuild facility is local), he showed me their shop and what they did to rebuild shocks a few years before I decided to my shocks. The "adjustability" of these old shocks isn't like the "adjustability" of modern shocks, it is in Koni's words, only a "wear compensator". For me cleaning out the internals and replacing the oil (the motocross world has a huge array of shock oil) returned them to acceptable street performance. Sending them to a rebuilder would most likely gain a performance check on a shock dyno. If you want to dial in the shocks for something like track days then buying new adjustable shocks would be a better choice. Just sharing what I did as a budget friendly option for those curious about what's inside the shocks. After a career in engineering R&D I still like to take things apart to see how they work. Image Unavailable, Please Login Image Unavailable, Please Login
Shocks minimize spring compression rebound oscillation. If the car is bottoming out, the problem is the springs.
I've ordered the Wilbers units, and will report after they are installed and I've driven the car for some mileage. Thanks everyone for your comments and suggestions.
Yup, funny that when words get abbreviated meaning is lost. Shock damper... Function: to dampen shocks and oscillations.
Hi how do you like those shocks I'm ordering a set, Wilbur says and their website says it's the c40ts shock. Do you know if this is what they sent you it looks like they make the decision based on your car and weight. The front and rear look different because they have different article numbers on the website probably for the spring rates. Thank you John