A PSA about KYB shock absorbers

[flaviaman]

Several years ago I purchased a pair of KYB rear shocks off Fleabay for my 850 Coupe, part number 343136. Being gas shocks they are extended unless force/weight is used to compress them. About a year ago immediately after filling the tank with 6.5 gallons of Chevron at $3.49 a gallon I compressed the suspension over a good sized bump, and the rear shock mount on the control arm fractured, the ride height is stock. At first I thought this was a metallurgical issue, last week (!!!) I took it apart and came to the conclusion the issue was the shock

being too long when compressed for the application. Rather than the bump stop on the suspension absorbing the energy the lower shock mount acted as the bump stop.....

I acquired some Boge units which match the spec's in the shop manual and a shop is welding up the shock mount. The Coupe will live again!

 

[dnudelman]

I wonder how the coil over guys are doing?

 

[NigelProdrive]

KYB suck. They also blow. Even what they market as performance suspension is junk.

 

[Ics19]

part number 343136.

I had a quick look on summit racing and no 850 (or any FIAT) is in the fitment for that part - possibly listed wrong on eBay?

 

[Dave Bassett]

Several years ago I purchased a pair of KYB rear shocks off Fleabay for my 850 Coupe, part number 343136. Being gas shocks they are extended unless force/weight is used to compress them. About a year ago immediately after filling the tank with 6.5 gallons of Chevron at $3.49 a gallon I compressed the suspension over a good sized bump, and the rear shock mount on the control arm fractured, the ride height is stock. At first I thought this was a metallurgical issue, last week (!!!) I took it apart and came to the conclusion the issue was the shockView attachment 63809View attachment 63810View attachment 63811 being too long when compressed for the application. Rather than the bump stop on the suspension absorbing the energy the lower shock mount acted as the bump stop.....

I acquired some Boge units which match the spec's in the shop manual and a shop is welding up the shock mount. The Coupe will live again!

Which Boge units? Enquiring minds want to know!

 

[Dr.Jeff]

KYB suck. They also blow.

Bart Simpson: "It defies the laws of physics, it sucks and blows at the same time".

I've seen Bilstein "sport" shocks (KYBs are the same high pressure Dr. DeCarbon design) also break mounting tabs on other cars. They are stiff.

 

[kmead]

Bart Simpson: "It defies the laws of physics, it sucks and blows at the same time".

I've seen Bilstein "sport" shocks (KYBs are the same high pressure Dr. DeCarbon design) also break mounting tabs on other cars. They are stiff.

I think that was stolen from Mel Brooks…

 

[Dr.Jeff]

I think that was stolen from Mel Brooks…

Now that you mention it, that does sound familiar from a Brooks line. However I know Bart also said it in a couple episodes. I imagine the Brooks version came first and Matt Groening copied it.

 

[tvmaster]

Several years ago I purchased a pair of KYB rear shocks off Fleabay for my 850 Coupe, part number 343136. Being gas shocks they are extended unless force/weight is used to compress them. About a year ago immediately after filling the tank with 6.5 gallons of Chevron at $3.49 a gallon I compressed the suspension over a good sized bump, and the rear shock mount on the control arm fractured, the ride height is stock. At first I thought this was a metallurgical issue, last week (!!!) I took it apart and came to the conclusion the issue was the shockView attachment 63809View attachment 63810View attachment 63811 being too long when compressed for the application. Rather than the bump stop on the suspension absorbing the energy the lower shock mount acted as the bump stop.....

I acquired some Boge units which match the spec's in the shop manual and a shop is welding up the shock mount. The Coupe will live again!

Do you see this as a 850 problem, or any FIAT from our era? Isn’t this what MWB sells as standard issue?

 

[Jeff Stich]

I was under the impression that this particular KYB shock was not designed specifically for the 850, which is why you'll not find a KYB catalog listing for it & no other sellers are offering it for the 850. The eBay seller has merely been marketing the shocks towards 850 owners.

 

[Dr.Jeff]

Also this is regarding a KYB "Gas-A-Just" shock. That is a high pressure gas design. The only KYBs for the X are the "Excel-G" model. Those are a normal hydraulic design.

 

[Jeff Stich]

Also this is regarding a KYB "Gas-A-Just" shock. That is a high pressure gas design. The only KYBs for the X are the "Excel-G" model. Those are a normal hydraulic design.

The discussion was about KYB shocks being used on an 850 Coupe, not KYB struts on an X1/9.

 

[Jeff Stich]

I took it apart and came to the conclusion the issue was the shock being too long when compressed for the application.

What is the difference in length between the KYB when fully compressed versus the Boge when fully compressed?

 

[Dr.Jeff]

The discussion was about KYB shocks being used on an 850 Coupe, not KYB struts on an X1/9.

Do you see this as a 850 problem, or any FIAT from our era? Isn’t this what MWB sells as standard issue?

Tvmaster only owns a X, and he asked if this applies to other models aside from a 850. So I was responding to him. I should have quoted his post (#9) to make it more clear.

That being said, the information about the two different models of KYB shocks still applies to any Fiat. The high pressure of a "Gas-A-Just" can cause mount breakage (the actual topic of this thread). It is a very stiff unit. In post #1 flaviaman described the Gas-A-Just model, but he showed a picture of the Excel-G, so I'm not sure which shock he is referring to.

 

[flaviaman]

What is the difference in length between the KYB when fully compressed versus the Boge when fully compressed?

That is an excellent question. I considered drilling a hole in the shock to compress it (being a senior citizen who has consumed far too much tortellini and Lambrusco I am not as strong as I used to be) but as it is filled with nitrogen I decided against it. I will take it to our hydraulic press at work, compress it and measure it.

These KYB units were marketed towards 850 owners on eBay and I never did find an application listing. Given the age and comparative rarity of our cars that did not surprise me too much however I should have done more research.

Regarding the part number of the new shock regrettably I just realized they are not Boge but rather Sachs, p/n 814102. My apologies....blame it on Lambrusco and the fact that Sachs is close to Sashia, I dated a Sashia years ago (insert smiley face here). Fortunately I never dated a gal named Boge....

I really wish Koni Classic would do a run of shocks / dampers for our cars. Spax used to make units, though they were very pricy and I have heard far too stiff.

Stay tuned for measurements ( of shocks, not Sashia).

 

[dnudelman]

I suspect that Zastava is still in production.

 

[tvmaster]

Tvmaster only owns a X, and he asked if this applies to other models aside from a 850. So I was responding to him. I should have quoted his post (#9) to make it more clear.

That being said, the information about the two different models of KYB shocks still applies to any Fiat. The high pressure of a "Gas-A-Just" can cause mount breakage (the actual topic of this thread). It is a very stiff unit. In post #1 flaviaman described the Gas-A-Just model, but he showed a picture of the Excel-G, so I'm not sure which shock he is referring to.

So what‘s Matt selling, for an X19 at least:

Strut - Rear - KYB Nitro Gas (Fiat Bertone X1/9 1980-88 + 1973-79) - NEW

Strut - Rear - KYB Nitro Gas (Fiat Bertone X1/9 1980-88 + 1973-79) - NEW

www.midwest-bayless.com

And for the 850. Funny, I would have naively thought they’d use the same shocks :/

Shock Absorber Rear (Fiat 850 All) - NEW

Shock Absorber Rear (Fiat 850 All) - NEW

www.midwest-bayless.com

 

[dnudelman]

So what‘s Matt selling, for an X19 at least:

Strut - Rear - KYB Nitro Gas (Fiat Bertone X1/9 1980-88 + 1973-79) - NEW

Strut - Rear - KYB Nitro Gas (Fiat Bertone X1/9 1980-88 + 1973-79) - NEW

www.midwest-bayless.com

And for the 850. Funny, I would have naively thought they’d use the same shocks :/

Shock Absorber Rear (Fiat 850 All) - NEW

Shock Absorber Rear (Fiat 850 All) - NEW

www.midwest-bayless.com

those at midwest look similar to these for sale in Slovenia

Fiat 850 Coupe Spider Special Berlina front shock absorbers left right ANT - Oldtimer-shop

Pair of new front shock absorbers for all types of: Fiat 850 Berlina (sedan) Fiat 850 Special Fiat 850 Spider Fiat 850 Coupe Fiat 850 Sport Coupe...

oldtimer-shop.eu

 

[kmead]

So what‘s Matt selling, for an X19 at least:

Strut - Rear - KYB Nitro Gas (Fiat Bertone X1/9 1980-88 + 1973-79) - NEW

Strut - Rear - KYB Nitro Gas (Fiat Bertone X1/9 1980-88 + 1973-79) - NEW

www.midwest-bayless.com

And for the 850. Funny, I would have naively thought they’d use the same shocks :/

Shock Absorber Rear (Fiat 850 All) - NEW

Shock Absorber Rear (Fiat 850 All) - NEW

www.midwest-bayless.com

Very different cars with vastly different suspension systems (and nearly everything else aside from calipers, bulbs and a few relays). The 124, X and 850 are completely different platforms and share very little. The 850 is basically a 50s car (an advanced one in many respects at least by the time the 850 was enginneered), the 124 a 60s car and the X a 70s car in regards to technology and engineering of their systems.

As a result what may be an issue with an 850 has no bearing on an X

 

[Jeff Stich]

Regarding the part number of the new shock regrettably I just realized they are not Boge but rather Sachs, p/n 814102.

Nothing to regret, Sachs made good shocks back in the day (usually painted orange on the main body with a black upper cap). I didn't realize they were still available new. The ones to regret are the Cofab units currently offered new (also painted black).