DOZENVALVE

jim, that video was awesome. I didn't know that

and those are some sexy springs by the way

NE frmhnd

The 1000 series pro-comp is also a non-charged, hydraulic shock. And about $10 less apiece. I have a set ordered for the whitferd at work, will let you know how they work. That thing is getting downright dangerous to drive.

I ran across some Skyjackers that were also hydraulic.

bobva

Yesterday I removed the the 4year old Gabriel gas shocks off the rear of my truck.
Still fully charged and in good working order the best I can tell.
Replaced them with skyjacker 7000,, Id say 70% improvement with that alone. Later today Ill replace the Skyjacker M95s 2years old.

Also just got off the phone with skyjacker. Gabriel makes the shocks for both skyjacker & procomp. Monroe makes the Ranchos


http://gabriel.com/2011/06/how-to-ch...ut/?ytt=01m48s

james1

I'm sure there is much misinformation in circulation regarding vehicle shock absorbers. Even the name is confusing -- the shock from hitting a pothole is actually absorbed by the spring, while the "shock absorber" dampens the bounce.

A number of years ago I did a bit of research regarding monotube ("gas") vs. twin tube ("hydraulic") shocks and I purchased some ProComp monotubes. They stiffened my ride and I have regretted it ever since. (Koni and Bilstein are also a monotube design; KYB manufactures both.) I've contemplated switching to adjustable Ranchos (twin tubes) but I've simply procrastinated. Monotubes are clearly a superior technology for car racing applications but, as Jim Lane has discovered, twin tubes may well be better for our old trucks.

Here is an excerpt from some info I found more than 10 years ago:

ISN'T A GAS SHOCK BETTER THAN AN OIL SHOCK?
Yes and no. A popular misconception is that a gas shock works on gas where as an oil (normal) shock works on oil. All conventional automotive shocks work by forcing oil through a programmed set of holes, however a gas shock will use compressed gas to keep the oil under pressure.

This is done largely to minimize aeration or "foaming" of the oil which would reduce the effectiveness of the shock as air passes through the valves rather than fluid. To see what this is like, tip a conventional shock absorber upside down and pump the shaft a few times. You'll notice the movement become jerky and uneven as oil and air intermittently pass through the valves.

The gas also helps to dissipate heat which keeps the oil cooler and maintains the viscosity and therefore the shock "rate". Gas shocks are ideally suited to long travel applications like rallying and off road. In fact, this is where the technology was primarily developed in the first place as lots of spring travel over big bumps really tests a conventional hydraulic shock.

There are many types of gas shock: twin-tube, mono-tube and remote canister combinations for super heavy-duty use like rallying and off-road racing. Most of the economical gas shocks are of a twin tube construction (low-pressure) where as most performance or race gas shocks use a mono-tube (high-pressure) system. There is no such thing as an ideal system, it really depends on the application as mono-tubes may have advantages in some respect but the high-pressure gas can act as a spring complicating the suspension design process.

The main disadvantage of a gas-pressurized shock is cost; more of it compared with a conventional hydraulic. Which leads to a very simple rule of thumb to help avoid confusion. If faced with a choice of gas or oil for the same price, it's unlikely that the real working part of the gas shock is of the same standard and level of sophistication as the oil. You get what you pay for. And, choosing gas shocks generally mean you'll need to design the rest of the suspension system around that fact with spring and bar rates being affected.

bobva

Some good info http://www.therangerstation.com/tech...t_Shocks.shtml

NE frmhnd

Actually, they damp the bounce. They don't moisten it.

james1

You are correct; although dampen can also mean to deaden, damp is the clearly the better transitive verb here. Good catch; thank you.



That's a great explanation of how various shock absorbers work; thank you. I'm now resolved; After running monotubes for about 60k miles, I'm going to switch back to relatively inexpensive twin-tubes -- probably the Rancho 9000 adjustables.

NE frmhnd

I got the pro-comp 1000's on the whitferd (87 f150) last week. You can now hit a pretty good hole with it and barely feel the back wheel hit. Front is still pretty rough though.

SeaW250

Any improvement in replacing the skyjackers with the hydraulic shocks?

BC847

I recently removed the perfectly good Bilstein gas charged and installed some ProComp straight hydraulics after reading Jim's informative thread.

My biggest critic (she who rides in "The Bouncy Seat"), agrees, they are a BIG improvement.

Thanks for the tip Jim!

SeaW250

Were the OEM shocks gas filled on these beasts?

BC847

No.

bobva

The Jury is back in.

2 years ago I replaced my dead front springs with the 2'' lift parabolic springs. At that time I put the skyjacker M95 on the front of the truck I felt she rode just fine going down the road. On some bridges she would bounce more I blamed that on the bridge after all my subaru outback would also bounce just not as bad.

3 weeks ago replaced all 4 with the SJ 7000. I"d say it s a big improvement on the ride. She still does not ride like a 74 Buick Electra or a D250 CTD but I dont expect her to ride like that.

SeaW250

Great feedback guys. Thanks to a combination of the frugal mechanic website and what must of been a pricing erron on Amazon, I got the new Skyjackers for $15 each plus free shipping (only the fronts though at this price). Discount disappeared after I bought the only two of three available. Lucky.

BC847

Not to complicate things but, I was digging around my '93 trucks stuff and noticed "Gas-Charged Heavy Duty Shock Absorbers".

- Second to last line in the first paragraph under Standard Equipment (ZOOM in if need be):