Neatrix bushings - glue or grease?

Navaros911 · 03-03-2006, 05:36 PM

Gentlemen,

I'm in the process of replacing my rear bushings with Neatrix' bushings - after cleaning up and using por-15 on the inside of the torsion bar tube.

The question that I have is: why do I need to glue the busings to my springplate?

Can't I just use grease on the outside and the inside of the bushing?

This may cause the bushing to be static to the torsion bar tube, but the springplate is rotating IN the bushing. This is exactly the opposite of what the OEM stuff does. Will this have a negative effect?

Is there any reason not to do it this way?

Thanks,
Michiel

patkeefe · 03-03-2006, 05:54 PM

I greased mine. The glue won't stick anyway. Worked out well so far, street and track, and no squeaks.

Do a search...a million posts on this subject.

Pat

Mike Feinstein · Mike Feinstein's Garage

Grease baby!

imcarthur · imcarthur's Garage

As above . . .

I re-indexed mine 1 week after install with glue & the glue was already kaput.

Ian

Navaros911 · 03-04-2006, 02:20 AM

Thanks guys!

I did do a search and there are many threads out there about this subject, but none that I read (roughly 15) answered this question directly. Most were a debate of some people using glue and others grease between the springplate and the bushing.

Also opinions can change over time when the product has more miles on it.

So my conclusion is:
- I may as well use the grease between the springplate and the busing, as the glue doesn't hold
- it doesn't matter if it is the springplate rotating in the bushing or the springplate AND the busing rotating in the torsionbar tube

I'll crawl out of bed now and get right to it

ZOA NOM · ZOA NOM's Garage

I sprayed with silicone. No squeaks yet.

Evans, Marv · 03-04-2006, 12:20 PM

I'm kind of a fan of using the silicon caliper grease on just about anything plastic or rubber.

rusnak · 03-04-2006, 08:57 PM

There is an excellent demonstration of the rubber bushings and what they do on the Elephant Racing website, in the portion showing the polybronze bushings vs. plastic.

http://www.elephantracing.com/techtopic/polyurethanefriction.htm

I decided against both bronze and plastic to restore the factory ride quality that I fell in love with in the first place.

Reading that web page made me want to go out and find a strong enough adhesive that will hold, and sort of explains why the Neatrix bushings came with "glue" in the first place.

So far I have done a test of Locktite Construction Adhesive. I glued a two pieces of pipe together with some rubber in between. I'll go back later to see if I can twist them apart. I think I'll see what 3M has to offer, maybe other brands.

I think this is worth solving for other 911 owners in the future.

Zeke · 03-04-2006, 09:33 PM

The inside of the torsion tube is not a nice smooth surface for a bushing to ride around in, so i glue the big end. The thing is, you have to get it perfectly in line with the shaft, or there will be squeaks. Some have had to open up the inner diameter on a lathe to get a nice slip fit just on the snug side. Ii won't work if they are too small in the inner diameter.

Anyway, the cars I've seen are rusty and pitted in the tube. I use polyurethane sealant and caulk for these bushings and body seams. Do it once and hope not to take it back out. Poly is as tough as it gets.

The brand I buy is PL. Black, white, clear, grey and some tans.

rusnak · 03-06-2006, 10:40 AM

I appreciate the tip on silicone grease.

I was trying to say three things here.

(1) I prefer to stay with rubber spring arm bushings for their noise isolation. (Otherwise I would go with the poly-bronze over the plastic.) The Neatrix busings are harder than factory, so I'm trying them out. The issue here is metal on metal vibration, or plastic on metal. I would not be able to stand that for very long on the lousy roads out here in cenral California.

(2) The illustration on the Elephant Racing website shows that rubber busings offer some spring rate resistance, as well as low friction, but they must be fixed relative to the car's body and the spring arm.

(3) Therefore, greasing them will not maintain the original engineering solution that the car was designed with. I really think that there must be a modern adhesive out there that will provide a bond similar to the original moulded vulcanized spring arm. The Super Glue that the Neatrix rubber bushings came with is clearly not up to the task.

I came across a German adhesive called Sika (www.sika.com) over the weekend in a Formula 1 racing magazine. It is described as an OEM adhesive. I'll check it out.

Superman · 03-06-2006, 11:45 AM

Clean up the springplates and the cavity in the body that will house and touch the bushings. Coat the bushings with silicon grease and simply assemble.

crashmy911 · 03-06-2006, 12:35 PM

I would think if the bushings didn't turn in there alittle they would just tear.

rusnak · 03-06-2006, 12:39 PM

hey guys,

I don't disagree or begrudge anyone who wants to grease the busings. I personally don't think that grease will last a year.

I'm reposing this link
http://www.elephantracing.com/techtopic/polyurethanefriction.htm

because it perfectly illustrates what's going on with the factory rubber busings, and why Wayne states in his book 101 Projects "aftermarket bushings are not as good as the factory ones"......

I acknowledge I may end up buying the factory arm at $450 a pop. But again, there must be an adhesive out there that replicates the one piece factory radius arm.

movin · 03-06-2006, 12:44 PM

Funny, most suspension applications seen by other manufacturers don't bond rubber bushings at all.

rusnak · 03-06-2006, 12:51 PM

Yeah I guess the factory rubber bushing is not bonded at all, which is why it was so easy to remove. At one time at the Porsche factory there was this all metal spring arm. Then God said "let there me rubber on that spring arm" and there was rubber on the spring arm. And it was good. No man can duplicate God's creation which is why we don't think they should be bonded again, but greased.

(Sorry I could not resist. I'll stop posting here now)

randywebb · 03-06-2006, 02:22 PM

Hahaha - Did god intelligently design the spring arm?? You imply she let or caused it to evolve over time...

rusnak · 03-06-2006, 03:02 PM

omg I spit out my coffee laughing.

I had NOOO idea this topic would become so controversial

patkeefe · 03-06-2006, 05:15 PM

Do a search for spring plate bushings. The controversy is not new. BTW, when I said I used grease, it was really silicone based lube.

Navaros911 · 03-06-2006, 05:44 PM

Wow; I didn't know this one was still alive... but I'm laughing my head off on rusnak's post...

OK, since I got side tracked last weekend, the bushings aren't in yet.

I'll put grease between the springplate and the bushing, but no grease between the bushing and the body.

When I say grease I'll use the stuff sold by our host in the white jar... also referred to as "gorilla snot"; specifically sold for the plastic bushings.

PEL-SUSGRS8

Would this be OK to use on the bushing?

Thanks guys.

rusnak · 03-06-2006, 07:07 PM

IF (let's just play Devil's advocate here.....) OK, IIIIFFF
I were to put grease snot in there I'd want to tap and thread in a grease nipple so that I could re-grease it now and then. I really really think the best solution for the greaser devotees is the Elephant Racing polybronze bushings. Otherwise I think glue is the way to go.

Only one thing is that for the rubber to flex as designed I think it needs to be soft, like the factory rubber - but it eventually flows, as we all know.

There is an interesting reference to suspension engineering in "Driving Ambition" the book about the McLaren F1. Gordon Murray was stumped by the problem of designing a race suspension that had "deflection" so it would work well on the street. He bought a Porsche 928 and Acura NSX then tore them apart and studied the design. They eventually designed the car with solid suspension links that were isolated from the body with rubber mounts, similar to the 993. Puts my 'lil 911 to shame....