how to know when to replace shocks, springs?

[blacksambo]

[QUOTE=SlowPro48;265236] The exact same axle/frame contact points exist whether the spring helpers are there or not.

I'm not trying to be argumentative here but....the spring helpers do touch the axel at all times when the VX is in forward motion, so therefore they are constantly insulating the axel from the frame, thus causing a noise deadening effect.

I can also attest that this is one of the benefits I immediately noticed upon putting mine back in play after a period of abscence. My wife also noticed this benefit.

[SlowPro48]

I'm not trying to be argumentative here but....the spring helpers do touch the axel at all times when the VX is in forward motion, so therefore they are constantly insulating the axel from the frame, thus causing a noise deadening effect...

Sambo, I'm getting too old and tired to argue anymore. Nowadays I like to agree with people. I'm curious though - exactly how do you think the spring helper insulates the axle housing from the frame by being in contact with it? Do you know how a mechanic's stethoscope works?

Will you agree with me that the axle housing is attached to the frame via a center link, a lateral link and two trailing links, which provide a pathway for vibration (sound) to be transmitted to the frame?

Will you agree with me that the shocks and coil springs also provide a pathway for vibration?

Will you agree with me that these pathways exist whether the spring helpers are touching the axle housing or not?

Will you agree with me that when the frame-mounted spring helpers are NOT in contact with the axle housing it is physically impossible for them to transmit the vibration from said axle housing to the frame?

And finally, will you agree with me that when the spring helpers ARE touching the axle housing, they do not insulate but rather provide an ADDITIONAL pathway for noise from the axle housing to reach the frame?

Fortunately, they don't provide much of a pathway because rubber does not transmit vibration very well. That's why the links and shocks are rubber bushed and there are rubber donuts between the springs and the frame.

The spring helpers may damp some vibration/harmonics in the frame and maybe even in the axle housing simply due to the fact that they have mass and are bolted to the frame/touch the axle housing - like play-doh on a tuning fork or a string silencer on a hunting bow - but they in no way acoustically isolate the frame from the axle housing by making contact with it. I wish they did because I would appreciate a little less whining from my differential.

Hey maybe I should bolt six or eight more spring helpers onto the backof the VX to quiet things down a bit!

Just think about it...

[SlowPro48]

Oh and to the OP: If your shocks aren't leaking fluid, just take them off the vehicle, pop the metal cap off the reservoir and clean everything up - especially inside the schrader valve. Take the shocks to a motorcycle shop or tire shop that has nitrogen and tell them you want 250psi. Then go to Lowes/Home Depot/Grainger/any plumbing supply place and get rubber caps and jubilee clips to replace the metal caps you destroyed. Put the shocks back on the VX and see if it helped.

If not, you can get them rebuilt as long as the shaft isn't bent or dinged up. But a lot of times, just pumping them back up will do the trick. It's the same principal that allows the water in your radiator to go well over 212 degrees without boiling - only at about 20 times the pressure. If the shocks aren't pressurized enough, the fluid will cavitate when forced through the shim stacks and you end up with a bunch of air bubbles in the fluid. It's like boiling water in a pot except it's caused by pulling a localized vacuum on the fluid instead of having the vapor pressure of the fluid exceed atmospheric pressure due to heating. But the end result is the same - bubbly, frothy fluid that offers no resistance when forced through the piston/shims and therefore shocks that don't damp.

Give the nitrogen a try - it's a cheap gamble...

P.S. you can use a drill and slide hammer to remove the caps or they're thin enough to just hammer an awl in and pry the cap off - but do your drilling/punching off center! The shrader valve is in the center!

[chadzu]

I just installed a set of moog 784 springs in my vx. You just have to cut off the pig tail and they are perfect for the isuzu. Depending on how much you cut off you get between about 3" lift to low rider I supose.
I am running 315 75 16 tires, so I went with 3". The ride is so much better than stock. It is like a new vehicle. I imagine that if you cut them so you had 1.5" it would still ride nice and you wouldn't have much lift. I got mine from Advance auto for $79 delivered.

[VX KAT]

Oh and to the OP: If your shocks aren't leaking fluid, just take them off the vehicle, pop the metal cap off the reservoir and clean everything up - especially inside the schrader valve. Take the shocks to a motorcycle shop or tire shop that has nitrogen and tell them you want 250psi. Then go to Lowes/Home Depot/Grainger/any plumbing supply place and get rubber caps and jubilee clips to replace the metal caps you destroyed. Put the shocks back on the VX and see if it helped.

If not, you can get them rebuilt as long as the shaft isn't bent or dinged up. But a lot of times, just pumping them back up will do the trick. It's the same principal that allows the water in your radiator to go well over 212 degrees without boiling - only at about 20 times the pressure. If the shocks aren't pressurized enough, the fluid will cavitate when forced through the shim stacks and you end up with a bunch of air bubbles in the fluid. It's like boiling water in a pot except it's caused by pulling a localized vacuum on the fluid instead of having the vapor pressure of the fluid exceed atmospheric pressure due to heating. But the end result is the same - bubbly, frothy fluid that offers no resistance when forced through the piston/shims and therefore shocks that don't damp.

Give the nitrogen a try - it's a cheap gamble...

P.S. you can use a drill and slide hammer to remove the caps or they're thin enough to just hammer an awl in and pry the cap off - but do your drilling/punching off center! The shrader valve is in the center!

These were my OEMs when I replaced them with Ranchos 9000XLS
I'm curious, is the rusty looking crudy end cap/piece in the first 2 pics indicative of them leaking something?

oh...and Hi V!...I'm hangin'....

[blacksambo]

[QUOTE=SlowPro48;265437]Sambo, I'm getting too old and tired to argue anymore. Nowadays I like to agree with people. I'm curious though - exactly how do you think the spring helper insulates the axle housing from the frame by being in contact with it? Do you know how a mechanic's stethoscope works?

Will you agree with me that the axle housing is attached to the frame via a center link, a lateral link and two trailing links, which provide a pathway for vibration (sound) to be transmitted to the frame?

Will you agree with me that the shocks and coil springs also provide a pathway for vibration?

Will you agree with me that these pathways exist whether the spring helpers are touching the axle housing or not?



I think you said it with the tuning fork analogy. The spring helper blends all these contact points into a balanced resonance and thus makes the clatter from this symphony of metal arms less prevalent .

I can attest from personal experience that it works this way. And my wife who has no particular mechanical expertise mentioned it first...."what did you do to quiet this thing down." Installed the missing spring helpers....simple.