The real issue is not whether they are gas or oil. The issue here is that your valving rate is too high for the spring rate of the car. In effect you have made the shocks ....into the load carriers. Shocks are only supposed to damp the motion of the torsion bars/springs.
This is a large part of my issue with companies who sell lowering or perfrmance replacement shocks for vehicles......based strictly upon how much you want to lower and what total combined stroke length you require. All of that information....leaves out the single most important piece of information that you needto be able to determine if the shock/strut will be able to function properly. You need to know
how much weight and enertia you are going to have to arrest. This will be based primarily upon how strong the spring system is and how quickly that spring must arrest not only the weight but the enertia of a loaded vehicle.
Lets look at the shock you selected: The KYB Gr-2 Excel G...part # 344428. Do you know what other vehicles that was designed to fit?
Here are the vehicles that shock fits:
Its a rear shock for a suspension with LEAF SPRINGS....and 1/2 ton carrying capacity
:
Leaf springs are very heavy duty and the ones on these trucks can completely suspend the weight of the load and heavy vehicle. On most of these 3000-4000 net weight vehicles, the rear weight alone is at least 1200 lbs..... empty. The valving on these is shocks has to be very stiff...because once a 1200 lb rear weight truck with say...1000 lbs of load gets busy compressing the leaf springs when you hit a bump....they need a pretty heavy duty shock valving to arrest that enertia. Once that compressed spring starts to unload a fraction of a second later...they need prtty stiff shock valving on the rebound stroke to arrest the upward spring rebound to keep the rear end from jumping into the air. As you can see....the operative word here is that shocks are to DAMP spring movement. You have shocks on your car...designed to arrest heavy enertial load over a relatively short stroke distance. Just because CIP1 "offers" these as a shorter stroke alternative...does not mean that the valving has been engineered
for your cars weight and enertia.
TOYOTA 4RUNNER (1984 - 1985)
TOYOTA 4RUNNER DLX (1986 - 1989)
TOYOTA 4RUNNER SR5 (1985 - 1989)
TOYOTA LAND CRUISER (1988 - 1990)
TOYOTA PICKUP (1984 - 1995)
TOYOTA PICKUP DLX (1984 - 1995)
TOYOTA PICKUP LN55 DLX (1986 - 1987)
TOYOTA PICKUP LN56 1984
TOYOTA PICKUP LN67 1987
TOYOTA PICKUP LN76 1986
TOYOTA PICKUP RN02 1993
TOYOTA PICKUP RN60 1985
TOYOTA PICKUP RN63 (1986 - 1987)
TOYOTA PICKUP SHT BD DLX EXC (1991 - 1992)
TOYOTA PICKUP SR5 (1984 - 1995)
TOYOTA TACOMA (1995 - 2004)
TOYOTA TACOMA REGULAR CAB (1995 - 1997)
TOYOTA TACOMA SR5 (1995 - 1997)
Another point to consider...leverage is everything with shock valving. As an example.....the KYB gas-a-just (high pressure) stock listed rear shock for a vw 411/412 is the identical shock.....that came on the FRONT end of a ford Econline 1/2 ton van. That generally has a V-8 in the front end. You might be thinking..."well...that should have the same problem as my car...meaning the damping would be too stiff". The reason why it does perfectly in both applications....the Ford van with about 1800 lbs of load over the axle and the VW 412 with maybe 900 lbs over the axle...is because on the 412....the shock and spring are out at the end of the trailing arm...about 32" from the pivot point...so the combined weight of teh body anddriveline exerts a lot of leverage against that shock. The Ford van has stubby little 16" A-arms under its 1800 lbs of weight on the axle....and they exert maybe half the leverage. Twice the weight X half the leverage....half the weight X twice the leverage...and you can end up with a valving package that works for both applications.
Do i have a part # solution for you? No....I don't.....but its clear that the valving is your problem. Ray
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