[chris_mac]

G'day

I bought a while ago a set of poly bushes, tried to install them today, but gave up. In my opinion when you install bushes they should fit rather tight in a spring and hangers eyes. Maybe not so tight that you need a press, but enough to press them by hand or with little force. They should not spin easly inside the hangers or springs. That would only give too much play on shackles and wear quickly.
Bushes I got are simply loose, if I turn spring sideways they fall out from spring eye. I guess 0.5-1mm too small diameter. What is your opinion about that. Should it be like that or they just shit. My experience is only with rubber ones and OME poly ones. They fit nice and tight.

Cheers
Chris

[BlueSuzy]

They are shit, Take them back if you still have the recipt.

[Fatzook]

Bruce could tell you more about this, but when you make a mould from an original part ( say in this case a new, genuine rubber bush was used to make the mould for the polly bushes) you must allow for a certain % of shrinkage ( maybe 10%??). I have no idea how they make allowances like this once the mould is made, but simply put, it sounds like the ones you have were made by a moreon

[Scrawny]

Yes, bushes should be a tight fit but I've run slightly loose bushes with no dramas. Poly is very hard wearing so shouldn't wear prematurely due to a slightly looser fit. I'm sure Bruce will be along shortly to correct me

[chris_mac]

Thanks guys for your advice, I will show someone the bushes tomorrow before I fire the guns at the manufacturer. I tried all off them today again and you can just shake them out of the spring. Maybe they still ok, but I don't like them and will try to get the money back.
Chris

[Bruce]

Yes you are right Fatzook (In a way)
Poly has a shrinkage rate of approx 1.5% so if we make a mould from an exsisting part then make a part from that mould the part will have a shrinkage of about 1.5%. Now this is not a worry in 99% of cases. I have been selling Sierra bushes for over 5 years with about a 99% happy rate. Have had a few people that did say that the size was a little small. We made our mould from exsisting parts.
If you look at a Rubber Sierra bush and compare that to a poly bush you will see that the poly is smaller. The reason for that is that rubber is meant to be a tighter fit into the spring. You can't make a poly mould to make poly bushes from a rubber bush because even tho you get shrinkage from the mould the finished produce will still be too large. It's a little hard to explain typing all this.
I've been doing poly parts for over 10 years now.
A Lot of people bag the shit out of poly bushes and that because a lot of people say they don't last or make lots of noise. The reason some poly bushes don't last is because there is over 50 different types of poly. Some work better in acids, water oil etc. A lot of companies that sell poly bushes will sell or make the cheapest type of poly they can use and then sell cheap. I made the decision right at the start that we would only use a really good poly. Hence why I am not the cheapest around but when selling parts to you guys I cut it to almopst nothing in profit.

People say that poly make a hell of a noise and that's because they don't use the correct grease.

[stockman]

I'm really happy with the bushes you sold me. They were a nice firm fit. I used castrol rubber grease, and have not heard a squeek from them.

[dank]

Sounds like you might be missing the steel sleeve that fits inside some springs. I know my OME springs I bought new about 5 years ago came with a steel sleeve on one spring end which the bushes were fitting inside that.

Just an idea and something to check.

[chris_mac]

Thanks for your opinions guys, I will contact the maker and we'll see where it goes.
I have sleeves in the springs (OME dakar, not the old type ones without the sleeves), I also checked the fit on the eyelet on the hanger, not only spring on the spring, just to be sure.

Kris

[lump_a_charcoal]

Yeah I saw them today, and IMO they are very loose fitting, even with the sleeved spring hole.

i don't think they should be able to fall out when the spring is tipped over?

[christover1]

Bruce wrote:

People say that poly make a hell of a noise and that's because they don't use the correct grease.

What is the best grease for polyurethane bushes?
IE the wishbone/caster correction bushes?
Thanks

[Bruce]

christover1 wrote:

Bruce wrote:

People say that poly make a hell of a noise and that's because they don't use the correct grease.

What is the best grease for polyurethane bushes?
IE the wishbone/caster correction bushes?
Thanks

Grease containing molydisulphide is the thing to use. Castrol LMM is one.
Mineral based grease will destroy poly. (But people use it and blame poly for being a shit product )

[christover1]

Thanks mate, will avoid petroleum greases, cheers

[Highway-Star]

Bruce wrote:

christover1 wrote:

Bruce wrote:

People say that poly make a hell of a noise and that's because they don't use the correct grease.

What is the best grease for polyurethane bushes?
IE the wishbone/caster correction bushes?
Thanks

Grease containing molydisulphide is the thing to use. Castrol LMM is one.
Mineral based grease will destroy poly. (But people use it and blame poly for being a shit product )

So I was right in using CV grease after all
Only used it because I buy CV grease in bulk

[christover1]

Highway-Star wrote:

So I was right in using CV grease after all
Only used it because I buy CV grease in bulk

I just checked my grease, it is LMM cv grease, so alls good.
CV grease is most often needed in the bush,
so its carried in me spare parts supply in the car.
I use it pretty much for everything in track side repairs.