Neatix spring plate bushing glue

[Superman]

Stiction. Hmmmm..... The resting weight on a front tire is, let's say 400 lbs. Let's say it's 600 lbs on a rear tire. When we hit a bump, those figures go, momentarily, to some pretty massive figures. Two or three or six pounds of "stiction" is going to make a difference? Or one pound (imagine hand-rotating a "stiction" joint without any spring or shock interference). Do I think "stiction" is something for non-Formula 1 teams to worry about? Nope.

I have Neatrix bushings on my spring plates. Very nice. I saw absolutely no good reason to glue them to anything. A thousand dollars says the outer surface does not move relative to the body, regardless of whether you glue it or not. And what if it did? Heck, if it did, it would help fight rubber bushing compression/sag over time. But that's just another thing I won't worry about. I expect these bushings to give excellent service for many years.

In all fairness, I would like to have Chuck's special, superduper skookum polybronze units. Perhaps some day. They are spendy, but I think they are a good solution. In the meantime, my Neatrix units will serve just fine. With no glue. In all the reading I have done on this issue, and all the various opinions and justifications and theories about deformation and blah blah blah, I think the glue idea is comical. At best.

I use silicon grease. Slipperiest stuff I know.

[ulrichd]

My experience with Neatrix bushings goes back to my 78SC. After the initial installation, I pulled the springplates for reindexing several weeks later and found that the inner bushings had become lodged in the tube (I used the glue supplied with the kit). This would suggest that the outer friction (bushing to tube) is great enough to break the glue bond (bushing to springplate).

Ulrich

[tonythetarga]

Originally Posted by ulrichd

My experience with Neatrix bushings goes back to my 78SC. After the initial installation, I pulled the springplates for reindexing several weeks later and found that the inner bushings had become lodged in the tube (I used the glue supplied with the kit). This would suggest that the outer friction (bushing to tube) is great enough to break the glue bond (bushing to springplate).

Ulrich

Same thing happened to me on my 86 after one drive to check ride height. I needed to re-index and found the glue did not hold. I believe I posted a question about this at the time and the answers I got back were to lube the bushing to springplate interface and forget the glue. Did that and so far, no issues.

[Superman]

Silicon grease.

[Chuck Moreland]

Originally Posted by Superman

Stiction. Hmmmm..... The resting weight on a front tire is, let's say 400 lbs. Let's say it's 600 lbs on a rear tire. When we hit a bump, those figures go, momentarily, to some pretty massive figures. Two or three or six pounds of "stiction" is going to make a difference?

The stiction case is really about bushings that slide, and not rubber bushings that deform.

However, the force of friction equals the friction coefficient multiplied by the normal force. In this case, the normal force is the weight resting on the bushing.

That means that the 2 or 3 lbs or friction force you feel when the suspension arm is disconnected and hanging in the breeze becomes much greater when the weight of the car is resting on the bushing. And as you point out becomes greater still when the bushing is loaded in a turn or bump situation.

To illustrate this point, consider a tire resting on the road - no car attached. You can easily slide the tire over the road surface with only a few pounds of sideways force. Now attach a car to it to increase the "normal" force. Takes a lot more force to slide the tire.

The exact same thing happens with bushings.

[barney911rs]

Personally I like my new 935 spring plates with the heim joint and no bushings at all. I had the weltmeister poly graphite bushings. I remember spending hours sanding them down to make them fit the torsion and spring plate tubes. Getting them back out was not much easier.

[88911coupe]

Been reading on this issue for some time and am about to install my Weltmeister Neatrix bushings from our host. These seem MUCH harder than the old rubber I've been scraping and burning off. In addition, it has a hard,shiny surface with some sort of lubricant on it. Bottom line...does not seem suitable to be glued in. The instructions discuss a lubricant but also say it's not required. My came with no glue or disucssion of glue. I guess I'll clean the surfaces up as much as possible and hope for the best.

[porschenut]

The only lubricant I used was soap and water on the outside of the bushing, just before inserting it into the torsion bar tube. Rather than use the glue that came with the bushings, I used a Permatex two-part epoxy to bond the bushing to the spring plate.

[Flieger]

Only rubber bushings get glued. Plastic ones get lubricant.

[bfunke]

I've wondered about this also. The 356 community seems to install the rubber bushings without any glue and lubricates them both inside and out. Seems to me there are several schools of thought on this.

[304065]

Chuck's correct- where the rubber bushings are used, it is the deformation of the rubber that allows for suspension movement. There should be no movement between the bushing and the metal on its ID and OD.

We know this for two reasons and I'll use the SWB case to illustrate it. The SWB bushings consist of a rubber bushing around a steel tube. The steel tube is fixed to the control arm. And when I say fixed, I mean, that when you change it out, it takes a blowtorch and an air hammer to get it off, it's FIXED to the tube. The outside of the bushing is another steel tube that gets held into the crossmember with a pinch bolt that is tightened down when the suspension is in droop.

The original factory workshop manual actually contains a warning about this. They tell you that when the pinch bolt is tightened with the suspension in droop, you can't let the arm subtend more than 20 degrees of motion, or you will rip the bushing.

Now, Chuck's polybronze bushings, or roller bearings are a different story: these are intended to be lubricated. As far as plastic bushings go, these were the only alternative 40 years ago, but today there are modern solutions that provide correct geometry, limit bushing compliance, have a much more linear friction gradient and are easier to service.

[Chuck Moreland]

304065 is correct, to avoid any confusion he is describing the front control arm bushings. And specifically he is describing 65-67 control arm bushings, which are different than the later parts.

On the spring plate bushings, there are comments above about them feeling lubricated when new. This is not intended as a lubricant in operation, but is an artifact of the bushing production. This is a mold release agent - it coats the mold before the rubber is injected. It prevents the rubber from sticking and allows it to be removed from the mold.

The mold release agents will interfere with the adhesive used to bond the bushings to the spring plate. Failure to remove this is one of the reasons the adhesive sometimes fails in operation.

On the Elephant Racing spring plate bushings, we wash them before packaging to remove the mold release agent. Literally, we have an old dishwasher for the task!

To supplement our cleaning, our instructions call for cleaning/degreasing the bushings and scuffing the ID with provided abrasive cloth to ensure clean rubber to get a good bond with the provided adhesive.

[Hodgey]

Originally Posted by Chuck Moreland

304065 is correct, to avoid any confusion he is describing the front control arm bushings. And specifically he is describing 65-67 control arm bushings, which are different than the later parts.

On the spring plate bushings, there are comments above about them feeling lubricated when new. This is not intended as a lubricant in operation, but is an artifact of the bushing production. This is a mold release agent - it coats the mold before the rubber is injected. It prevents the rubber from sticking and allows it to be removed from the mold.

The mold release agents will interfere with the adhesive used to bond the bushings to the spring plate. Failure to remove this is one of the reasons the adhesive sometimes fails in operation.

On the Elephant Racing spring plate bushings, we wash them before packaging to remove the mold release agent. Literally, we have an old dishwasher for the task!

To supplement our cleaning, our instructions call for cleaning/degreasing the bushings and scuffing the ID with provided abrasive cloth to ensure clean rubber to get a good bond with the provided adhesive.

There is absolutely no doubt Chuck has it nailed. His product comes with very specific detailed instructions on how to install. Stray from it at your peril.

neil

[88911coupe]

OK, just ordered and rec'd my actual Neatrix busings from our host who initially shipped the PG version. I did not know it was the wrong type so installed it and was astounded how loud/squeaky they are. Now preparing to go through this whole PITA again with Neatrix. Here's my question...can I follow Chuck's process on Neatrix bushing to minimize the noise or is that only applicable to Elephant's spring plate bushing? Goal is NO SQUEAKS....
If I understand Chuck's position the pressure of the interference fit keeps it from moving...correct? I've been doing some checking to find some glues but does not seem that anything can stand up to the sheer forces on this bushing.

[gtc]

Yes. The neatrix and elephant bushings are very similar.
Clean off the waxy mold-release compound, and super glue them onto the spring plate. I used several tubes of super glue. Better safe than sorry. Regular cyanoacrylate (sp?) superglue works fine.