Help on Rear Shock

[JohnnyViper]

I have a question on my 97 GTS. I'm working on installing spring caps on the rear of my car and pulled both the shock to adjust and compare them. I have followed Koni insturctions on how to adjust the rebound but when I compare the rebound on the two rear shock one returns to the top much faster. Is this an indication that on of my shocks is bad? I made sure I turned both shocks in the correct direction and hit the internal bump stop. I would figure they should rebound the same Hellllllllp

 

[Bexar80]

My shocks did the same thing and I tired several different methods nearly driving myself crazy. I also noticed the shocks varied in the maximum number of turns, about 1/8 or 1/4. I tried timing the expansion, but settled on just the number of rotations. I believe I set my fronts to 1 3/4, 180* turns and rears to 1 1/8, 180* turns. The car rides a ton better but I also installed lower spring caps, poly sway bar bushings, new tires and had an alignment done all at the same time.

 

[JohnnyViper]

yea one of mine goes so much faster and yes its driving me crazy, I'm just a little worried I have a bad shock i did the same as you, spring caps, poly sway bar bushings, recent tires and soon an alignment, thanks for your input!

My shocks did the same thing and I tired several different methods nearly driving myself crazy. I also noticed the shocks varied in the maximum number of turns, about 1/8 or 1/4. I tried timing the expansion, but settled on just the number of rotations. I believe I set my fronts to 1.5, 180* turns and rears to 1.25, 180* turns. The car rides a ton better but I also installed lower spring caps, poly sway bar bushings, new tires and had an alignment done all at the same time.

 

[Bexar80]

Actually I just found my post about the spring cap install that mentions how much I adjusted the shocks.

"They only turned about 3 half turns (180s). I set the back shocks to 1 and 1/8 half turns and the fronts to 1 and 3/4 half turns as others had done."

 

[Black Moon]

I have a question on my 97 GTS. I'm working on installing spring caps on the rear of my car and pulled both the shock to adjust and compare them. I have followed Koni insturctions on how to adjust the rebound but when I compare the rebound on the two rear shock one returns to the top much faster. Is this an indication that on of my shocks is bad? I made sure I turned both shocks in the correct direction and hit the internal bump stop. I would figure they should rebound the same Hellllllllp

I'm no shock expert but if they are rebouding differently then one is wearing out or maybe bad. Makes sense anyway. Do you notice a difference when you drive it? My gen3 was doing the same so we removed them. One you had to almost stand on to compress and the other could be compressed between your hands. The weak one didn't rebound at all. Bought a used set with the same mileage, check them first before installing and problem went away.

I think you can have gen2 shocks rebuilt can't you?
Good luck

 

[JohnnyViper]

i does make sense, I have only driven the the car for about 3500 miles and as far as I know the shock has been like this since i took ownership less than a year ago, never noticed anything wrong

I'm no shock expert but if they are rebouding differently then one is wearing out or maybe bad. Makes sense anyway. Do you notice a difference when you drive it? My gen3 was doing the same so we removed them. One you had to almost stand on to compress and the other could be compressed between your hands. The weak one didn't rebound at all. Bought a used set with the same mileage, check them first before installing and problem went away.

I think you can have gen2 shocks rebuilt can't you?
Good luck

 

[Black Moon]

Is there evidence of oil on the outside of the shock? Gen3 are oil filled. Not sure about the Gen2's but once everyone gets done with Easter I'm sure you'll get some sound advice. Better do a SEARCH before Phil jumps on you

 

[JohnnyViper]

i did search and i hope so, but your advise seems prety sound and there was no evidence of oil leaking from the shock.

Is there evidence of oil on the outside of the shock? Gen3 are oil filled. Not sure about the Gen2's but once everyone gets done with Easter I'm sure you'll get some sound advice. Better do a SEARCH before Phil jumps on you

 

[Bexar80]

Typically the only methods I know to judge if a shock is bad is if it is leaking, it will not expand and just falls back into compression or if it is noticeably easier to compress or expand than another. I think just watching the expansion of the shock in a load free static test really tells nothing BUT I would also assume they probably should expand at the same rate under the same load free static test.

I have heard of equipment that can test the performance of shocks. I recall a MB owner in Europe having his air shocks tested to solve a vibration he was having. I'll try to dig through the Benz forums to see if I can find the thread again.

 

[JohnnyViper]

thanks I really apreciate it!!!

Typically the only methods I know to judge if a shock is bad is if it is leaking, it will not expand and just falls back into compression or if it is noticeably easier to compress or expand than another. I think just watching the expansion of the shock in a load free static test really tells nothing BUT I would also assume they probably should expand at the same rate under the same load free static test.

I have heard of equipment that can test the performance of shocks. I recall a MB owner in Europe having his air shocks tested to solve a vibration he was having. I'll try to dig through the Benz forums to see if I can find the thread again.

 

[Bexar80]

A quick google search came up with these two interesting articles.

Shock Dyno

Build your own shock dyno

Looks like you can send them to Koni for adjustment, rebuilding and dyno-ing.
Knoi Services

 

[Dom426h]

Finding a performance shop with a shock dyno(cheap) or sending them into koni for a rebuild($$$) is the only way to know for sure. I remember hearing something about relief valve that is the only thing that opens when you push down with your punny human force and let go. On the road 10X the force is being applied to the shocks opening up the true valving. If your curious about wether what I said is true or not than pick up the phone and give Koni a call.