Horrid suspension, cured by lithium grease... but why?

[Chicane]

This is strange. My suspension is HORRIBLE. Clunks, rides like crap, makes a lot of noise... just sucks. I sprayed the front swaybar bushings with lithium grease, and for about 2-3 days, EVERYTHING IS QUIET, and it rides a LOT better.

Why??!? The bushings look like they're in good shape. I'm guessing that since they seem to be the cause, I'll need to replace them...but my question is why? I don't understand how bushings that APPEAR to look fine are making so much noise, and why some grease would quiet them so much?

- Rob

[svx_commuter]

Rob you are correct the lithuim grease will quite it down for a few days. I did the same thing. Here is what I think.
Have you noticed how tightly the rubber bushing squeeze the front sway bar? There is an awful lot of compression in the bushings holding the bar. This prevents the sway bar from turning. Does your sway bar look like mine? All the sway bar coating has worn off under the bushings. Have you looked at the bar with the bushings removed? The surface coating is gone, worn down to the metal and is now very rough.

Where does the noise come from? The bushings because they are so tight, prevent the sway bar from rotating. This prevents the ends of the sway bar attached to the link ends that attach to the struts from moving with the struts when the strut moves up over bumps. So I see it like this. The tire hits a bump, the strut tries to moves up but the resistance at the bushing delays the motion (because of the tight fit) and then the bar "snaps" and turns in the bushing. This lets the strut "pop" up and the noise comes thru the strut into the body.

I have beenable to push down on the bumper and get the same noise but only when the front of the car is on ramps. But you know that noise is more complicated than that. I have never been able to duplicate the nosie with the front wheels on the ground.

I think that salt has worked it way into the metal under the rubber bushings and the surface is corroded. This prevents the bar from rotating. Then when it snaps along comes the noise.

Well this might sound good but I can share with you a few more observations:
1. My SVX always had this noise but it was very faint when I first got the svx. It is now louder.
2. The noise was NEVER present above 15 mph and now I hear it up to 40 mph.
3. When teh SVX was newer, the noise was never heard when it was wet out. I think this is beacuse the water lubricated the rubber bushings.
4. I can make the noise go away for about 2 weeks now. This is done by spraying silicone on the rubber bushings and on the strut shaft with the svx jacked up. I prefer 3M with no hydrocarbons.
5. When I look real close at the compressed rubber bushings I can see that the split in the top is open. I think this is where the salt and water gets in. It is also the place to spray the silicone.
6. I found something recently about shocks used on old cars. I guess it was before we made hydraulic shocks. It was called a "friction damper" a series of washers on either side of an arm clamped the arm with a bolt. The bolt was the pivot point and the other end of the arm was attached to the wheel knuckle. As the wheel moved up and down the arm rotated and the washers resisted the motion. This arrangement reminds me of the rubber bushing on the sway bar. In a manner, the SVX rubber bushings are also a friction damper.
7. As Beav has pointed out and others, the bolts to the subframe may be loose and need tigtening.
8. As other have pointed out, the bolts that hold the lower control arms may need degreasing and retightening. The lower control arm has two large rubber bushings that get clamped by way of the bolts to the sub-frame. These bushing are supposed to be clamped in place with the wheels on the ground and full weight on the suspension. Leaking engine oil can find its' way into the friction joint between the bushings and subframe. This might allow the bushings to rotate and if so then the bushings will no longer "help" the control arm resist the up and down motion. This can be worse after a few hard landing after SVX leaves the road a few times. :D
9. There is also that possiblity that the bushings in the subframe have been sheared. The lower control arms tie into the subframe and the noise I hear may be the subframe hitting the frame. [I think it was Rufus(Mike) that found this on a parts car.]

My first choice would be to replace the sway bar. I believe the coating that is used helps to keep the bar rotating.

[Chicane]

What if I removed my current bar, sand blasted it, painted it, and reinstalled?

- Rob

[GreenMarine]

Wat color would ya paint it??? :D:D:D

[Porter]

You may also want to consider having it dipped in a hard rubberized plastic coating as an alternative. There are a number of products on the market for this, i.e. "PlastiCote" and others if I remember properly.

White lithium grease is the preferred sway bar bushing lubricant, both for its properties as a lubricant and squeak defeater, and also due to the fact that it displaces water effectively.

[wawazat??]

Originally posted by Porter
You may also want to consider having it dipped in a hard rubberized plastic coating as an alternative. There are a number of products on the market for this, i.e. "PlastiCote" and others if I remember properly.

I don't believe that a plasticized vinyl coating like PlastiCote will endure the abrasion and shearing effects of the rotation of the bar in the rubber bushing. I do think it will look pretty, at least for a short time :)

I'd recommend a more durable coating method like powdercoating after a good sandblast prep to eliminate any traces of corrosion.

Todd

[Beav]

Never use any type of petroleum product on synthetic rubber as it will rapidly deteriorate the rubber. Similar to trying to revert the rubber to its natural state - like thinning paint with paint thinner.

Preferred method of lubricating any rubber part is silicone lubricant. Pick up a bottle of Permatex Disc Brake Lube:

http://www.subaru-svx.net/photos/files/Beav/16257s.jpg

This is the proper lubricant to use on the sway bar (common prob on most cars), just remove the bushing clamps, spread the rubber open a bit and apply to contact area. Bolt the clamps back on and you're finished.

[svx_commuter]

Oh Beav I have tried that approach. The silicone grease works for awhile but the squeeze is so great in the SVX bushings, that the grease gets pushed out or moves it out or something.

As I remember the bottom of the Subaru is coated with b1tchomastic (spelling is wrong for sure) I think that is on the sway bar as well.

Beav, I have another question for you.

Any opinion on how your o-ring to valve cover bolt fix has worked?

[Beav]

I guess YMMV is the best opinion then, but white lith' will destroy rubber parts. I lubed my bshgs about two years ago and no noise since.

O-rings are working o.k. To tell the truth though, whenever I have an oil leak start up I pull and clean the PCV valve - the oil quits leaking immediately. Each time the oil leaks the PCV has been plugged shut. Just did this the other day for the third time in a little over two years. Was leaking from everything - cam & crank seals, valve covers and iris. Super engineering there, Subie guys. Why mount it upside down in the intake? Is it supposed to be like a storm drain?:rolleyes: Using my gripper pliers makes it a two minute job, thank goodness. A lot faster than replacing $eal$ and ga$ket$.

[oab_au]

Hi Beav, good to see you off the nest and back in action.:D

I have been saying for a while, that a engine that leaks oil from all points, has a breather problem.

A point that I have identified, as a cause of blockage, is where the two cam cover breathers run back to the bottom of the air box, attached to the throttle bodies. These connect to a tube that runs from one side to the other, that is not open to the box, but they are connected through a small 1/4" orifice to another hose, on the RDS, that connects to the air delivery pipe.

This small hole blocks easely to seal the crankcase off from the intake pipe. When this is blocked it leaves the PCV valve as the only path for crankcase pressure to escape, and when the pedal is down the valve is closed, and the crankcase is sealed when the blow past is at its greatest. Oil leaks fom every seal and gasket.

Harvey;)

[Beav]

Good spotting, Harvey. I'm not used to the air supply being the culprit, most of the cars I see have PCV valve and hose issues. Now I'm leery to inspect my breather hose. If I find it to be clogged and clear it the seals and gaskets may begin leaking again due to not having vacuum sucking them down tight. :rolleyes: :p

[oab_au]

Originally posted by Beav
Good spotting, Harvey. I'm not used to the air supply being the culprit, most of the cars I see have PCV valve and hose issues. Now I'm leery to inspect my breather hose. If I find it to be clogged and clear it the seals and gaskets may begin leaking again due to not having vacuum sucking them down tight. :rolleyes: :p

Its not the sucking mate, its the blowing:D

When its on vacuum, the air goes down these breather hoses, through the crankcase, through the PCV valve to the inlet manifold, for burning. When its on full throttle, the piston blow by, goes the other way, as the PCV valve is closed. From the crankcase up the two breather hoses, through this small bloody hole to the inlet pipe then through the throttle bodies to be burnt.

I had a big single four stroke bike that I did up for club racing. Could not stop the massive oil leaks that came from every where. Eventually fitted a larger breather pipe, never leaked again.

Harvey.;)

[svx_commuter]

Well this is for the people with more experience.

Does the PVC valve have to stay screwed into the manifold?

Is it possible to drill the PVC out so that it becomes an adapter for the hose (or buy one) and then add another piece of hose and a different PVC that just gets pushed into the hose ends?

This way it may be possible to get the thing into a more accessable area.

What do you think?

[oab_au]

Gid'ay John, I guess you could fit the PCV in the hose section, if it would make it easer to get at, for cleaning. The main qustion is why it blocks so quickly. The way I see it is, if the system is working correctly, the valve should not goo up too quickly.

When the engine is running on vaccum, idling or cruising, the PCV valve is sucked opened to allow air from the air cleaner to flow through the crankcase, through the PCV valve to be consumed in the engine. When it is in this mode there is no piston blow by, so there is very little goo on the flow.

When the throttle is opened, a spring closes the PCV valve, as there is no manifold vacuum, the fumes caused by the piston blow by, now flow back the other way, from the crankcase through the breather hoses to the air box in front of the throttles.

If this path is blocked, then the pressure in the crankcase will rise to force the PCV valve open against the spring, to flow to the manifold that way. This is when the goo has to pass through the PCV valve to goo it up. It is this increase in crankcase pressure that causes the many oil leaks, some cars have.

Harvey.;)

[Beav]

The problem I have noticed, in so many cars today, is due to EFI intake manifolds being 'cold'. The hot oil vapors condense in the cold manifolds and collect like crazy. Many of us are beginning to use inexpensive air/water separators plumbed into the PCV hose in order to reduce the effect to a tolerable level. Some cars have very big problems resulting from the amount of oil getting into the tops of the cylinders and wreaking havoc with emission devices and carbon build-up on pistons and valves. Corvettes and Cadillac V-8s are notorious. In fact, Cadillac dealers are having to use several applications of their extremely strong top engine cleaners in order to remove the deposits that cause piston/carbon/head contact noise/knocking and detonation.

The separators are drained at each oil change and really do help.

This is an industry-wide issue. Watch in the near future for innovative changes to the system in order to alleviate the problem.

[Porter]

White lithium grease IS the proper lubricant to use if you have urethane bushings.

And... Whiteline swaybars are coated in a blue rubberized plastic coating. The key is they are used with urethane bushings and lithium grease. I've never seen one bind no matter how much pressure is involved as long as they are lubricated properly.

[Chicane]

Hrm. Thanks for the info porter. Plasti-dip would work.. because I plan on getting urethane bushings fairly shortly, when I'm doing my suspension. SPEAKING OF WHICH, please email me back. PLEEEAAASSSSSEEEE..

- Rob