back to building...
I will be using polyurethane bushings on my suspension
Is it worth to go through the hassle of drilling, tapping and installing grease nipples on allot se of the pivot points?!?
Thanks for your comments
Good idea , maybe. I considered it myself
Worth the bother, probably not
IMHO better to spend the time matching and sizing the crush tubes to avoid them binding when tightened up
grease well when you assemble and that should do for quite some time
http://www.locostbuilders.co.uk/viewthread.php?tid=5903
worth a read..........
I was tempted, but I think I'd prefer to stick with the hassle of disassembly once a year to regrease. It'll give me the opportunity to
properly check things over for other issues, rather than just sticking a hose on and filling them up oblivious to other issues.
What I am going to do is use teflon washers either side of the bushes, between the top hat and the bracket.
quote:
Originally posted by cliftyhanger
http://www.locostbuilders.co.uk/viewthread.php?tid=5903
worth a read..........
Exactly. Nobody seems to have an answer!
BUT from what I can make out, you do not want any lubricant between the bush and the outer housing. I think the inner crush tube rotates in the bush,
unlike rubber where the rotation is taken up as distorting the actual rubber. You do not want the bolt rotating in the crush tube either, though
copperslip or similar should be used so everything comes apart nicely (after 15 years of everyday use, copperslip meant every nut and bolt came apart
easily on one of my old cars)
If you wish, a little grease between the tube and the bush should do no harm. I assume grease does not attack the poly, but a chap I know (who happens
to be a rocket scientist as his day job) was adamant that silicone grease is the only one that should be used.
See, nothing is as clearcut as it really ought to be!
Yes it's worth fitting.. I am thinking of doing this soon. Poly bushes DO need lubricating in this application. If they are creaking something is
binding sign that fatigue is setting in. People have had failures at the 1000's mile mark, do a search will find the issues..
To do it properly requires a bit of thought to ensure the grease is distributed.
Dan
But how do you get the grease nipple to feed grease to the crushtube/bush interface?? That is where the movement should be taking place.
If a polybush is breaking down at 1k, it suggests something is wrong in the design of the joint, probably less than optimal alignment, or just poor
design. Or maybe using unbranded bushes, plenty of cheap versions out there on the bay.
quote:
Originally posted by cliftyhanger
But how do you get the grease nipple to feed grease to the crushtube/bush interface?? That is where the movement should be taking place.
If a polybush is breaking down at 1k, it suggests something is wrong in the design of the joint, probably less than optimal alignment, or just poor design. Or maybe using unbranded bushes, plenty of cheap versions out there on the bay.
Problem arises with what grease you propose to use and then how to get it through the grease nipple? Wouldn't fancy the cost of packing a grease gun with the polyurethane friendly stuff. A manufacturer of polybushes told me their bushes should last 40k (road use) before needing attention if greased and assembled properly. How many miles a year are you expecting to cover?
We make polyurethane bushes for various cars, however we are too far from competing Powerflex, but our country is'nt big.....
PU bushes can be great solution if correctly choosed and serviced. Greasing can make huge difference in life of the bushes......
IMHO marine grease is bit better than copper based one.
Using poly bushes on tracks for many years, and never had even single hassle with it.
Did my mid-engined locost with PU and no regrets.....
However bushes for everyday use locost, and trackday one can not have same characteristics......
Thanks for your input.
To put all in one post:
- No grease or lubricant between bush and housing.
- silicon or synthetic preferred over copaslip or mineral grease
- good idea the Teflon washers.
- as above, the point about disassembling every year is good, but maybe overkill.
It is stated on the busing packing that they're oil and grease resistant so no problem with going mineral based
Best regards.
Angel Acevedo