andyace
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| posted on 1/11/05 at 09:50 AM |
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Locating Molybdenum Disulphide Grease and Fitting Polybushes
Hello all,
Just looking for the above. Where is the best place to get this from.
In local shops I have so far found a grease described as 'lithium based grease with added molybdenum disulphide.
Halfords have a castrol product called moly grease, is this what I need, it does not say on the tin what it contains!, it is a dark grey colour.
I want to make sure I put the correct stuff on the polybushes.
ALSO :
When assembling the polybush I intend to insert the bush dry into the wishbone then lubraicate the crush tube and inside the polybush, is the correct?
A friend of mine said to lubricate the polybush before putting it in the wishbone. This does not sound right as the polybush is not intended to spin
in the wishbone.
[Edited on 1/11/05 by andyace]
[Edited on 1/11/05 by andyace]
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Peteff
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| posted on 1/11/05 at 10:31 AM |
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Moly grease is the stuff. The one with added moly will be the same thing, usually dark grey in colour.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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MikeRJ
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| posted on 1/11/05 at 11:22 AM |
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quote:
Originally posted by andyace
This does not sound right as the polybush is not intended to spin in the wishbone.
No it's not, but sometimes the bushes are a very tight fit in the tubes and lubricating them makes assembly significantly easier.
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andyace
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| posted on 1/11/05 at 11:43 AM |
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The polybushes although a tight fit can be pushed into the wishbone by hand.
Is it better to leave them unlubricated thereby encouraging the polybush to spin on the crush tube rather than the polybush spinning in the wishbone?
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Peteff
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| posted on 1/11/05 at 11:52 AM |
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Martin used to recommend loctiting the bush into the wishbone tube so it would only spin on the crush tube.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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NS Dev
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| posted on 1/11/05 at 11:57 AM |
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you "may" need to lube the polybush to enable getting it into the bush tube as they are tight, but washing up liquid will do that just
fine.
polybushes don't need lube in operation. Lubing them will reduce their life.
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andyace
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| posted on 1/11/05 at 12:06 PM |
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Whats the purpose of the grease then? Is it purely an aid to get the crush tubes in and to stop them creaking ?
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NS Dev
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| posted on 1/11/05 at 12:16 PM |
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who said to use grease?
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andyace
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 posted on 1/11/05 at 12:28 PM |
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Lots of mentions in the threads below, seems to be related to stopping the polybushes seizing and creaking. Also would it encourage the polybush to
ratate on the crush tube rather than spin in the wishbone tube.
On that point is the use of loctite as mentioned above a good move.
Help !!
http://www.locostbuilders.co.uk/viewthread.php?tid=26686&page=1
http://www.locostbuilders.co.uk/viewthread.php?tid=31900
http://www.locostbuilders.co.uk/viewthread.php?tid=9719
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NS Dev
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| posted on 1/11/05 at 03:49 PM |
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see what you mean.
The polybushes on my XR4x4 always creak, grease and wd 40 etc stops it for about 100 miles then they creak again.
Just ignore it!!
I wouldn't worry, I certainly used no grease on mine, just attracts dirt which wears things out and creaks even more!
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Hellfire
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| posted on 1/11/05 at 06:41 PM |
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OK, why not try inserting the PU Bushes into the wishbones dry. The voids between the two bushes can then be filled with Moly grease before inserting
the crush tube. We did them this way and no creaking so far.
If the bushes wear out prematurely, just replace them and lesson learned for next time. Got to be better than creaking suspension. 
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mookaloid
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| posted on 1/11/05 at 06:56 PM |
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As an aside, has anyone fitted grease nipples to their wishbone bushes? They would go into the void between the poly bushes and using them would force
clean grease in between the crush tube and the poly bushes thereby stopping creaking and making them last longer too.
Cheers
Mark
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mookaloid
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| posted on 1/11/05 at 06:58 PM |
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Incidentally I have used the red grease that is supposed to be for rubber and brake components.
Cheers
Mark
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Stu16v
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| posted on 1/11/05 at 08:18 PM |
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I assembled my poly bushes dry, and the suspension creaks like hell.
But at anything more than walking pace, you can't hear it anyway - so who cares?!!!
Dont just build it.....make it!
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NS Dev
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| posted on 1/11/05 at 10:19 PM |
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was thinking that!
The anti-roll bar bushes (posh name for old lumps of nylon) on my grasser make a right racket after a race when they have warmed up, but you never
notice when you're thinking of other things like driving, and WD 40 stops it for all of 5 mins on that!!
Silicone grease should be ok with polybushes but I would not stick mineral oil based greases on them unless I had to.
[Edited on 1/11/05 by NS Dev]
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blueshift
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| posted on 1/11/05 at 10:54 PM |
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The instruction sheet for the GTS Tuning polybushes say to lubricate the inner tube well for assembly, and keep it lubricated during the life of the
bush.
Darren of GTS used to work in F1 suspension design if I remember correctly, so I'll be taking his advice!
It doesn't mention what grease to use, but I'll be using moly.
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Rorty
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| posted on 2/11/05 at 08:15 AM |
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If possible, I jam the bushes into the wishbone eyes while the paint is still wet. That way they seal to the wishbone.
Moly grease is the prefered lube for PU, but all and any greases will dry out or migrate and will need replenishing. Just one of the prices you pay
for a superior performing material.
I wouldn't fit a grease nipple to the eye because the grease could easily squirm between the bushes and the eye under pressure.
I use PU bushes and stainless steel crush tubes for off-road racing and the fine dust and grit gets everywhere. Even so, I only ever had to replace
one crush tube because of wear.
It would be better for the crush tubes to wear rather than the wishbone eyes.
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
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NS Dev
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| posted on 2/11/05 at 09:11 AM |
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do you grease the crush tubes rorty?
With a lot of dirt flying around it's surely pointless as it will just dry out and turn into grinding paste
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Rorty
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| posted on 2/11/05 at 11:46 AM |
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quote:
Originally posted by NS Dev
do you grease the crush tubes rorty?
With a lot of dirt flying around it's surely pointless as it will just dry out and turn into grinding paste
Absolutely; the interface of the crush tube and bushes must be greased and also the interfaces of the bush flanges and wishbone brackets.
If they are left un-greased, the stiction negates any handling benefits.
These are always going to be relatively high maintenance cars and greasing the bushes regularly goes with the territory.
The other option is to use soggy Metalastic bushes with lower performance but virtually zero maintenance.
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
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smdl
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| posted on 5/11/05 at 06:04 PM |
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Nylon?
I have just re-read the bushings section of Chassis Engineering by Herb Adams. Interestingly, he is not a fan of (poly)urethane bushings -- for many
of the reasons that have been cited in this thread. Instead, he strongly recommends nylon, indicating that they offer enhanced performance, and only
need to be lubricated about every 6 months. Has anyone used nylon bushings?
Shaun
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Rorty
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| posted on 5/11/05 at 11:31 PM |
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Nylon is fairly old technology for bushes nowadays.
It is a rigid plastic so doesn't lend itself to bushes that require some compliance.
If the bushes can be guaranteed to rotate in just one plane, then acetal or PTFE would be a better choice as they don't absorb moisture and
therefore won't swell and they offer less stiction too.
Polyurethane is a better all round choice of material because of its compliance, reduced road noise, reduced vibration, and resilience to just about
every acid, solvent, grease used around a car.
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
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smdl
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| posted on 6/11/05 at 03:07 AM |
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Interesting. Thanks for the reply.
Shaun
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DarrenW
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| posted on 6/11/05 at 11:40 PM |
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What grade o poly bush are you using? I dont mean shore hardness here. Some poly bushes are meant more for undustrial machine antivibration purposes
more than automotive sportscar suspension. Some se7en types seem to suffer more than most. I rebuilt a Golf Gti a while ago using cheap bushes.
Supplied with red grease. They creaked to the point where they were extremely annoying and embarassing. So far my ZR hasnt creaked at all. They have a
special compound to prevent it and dont require any grease.
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Rorty
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| posted on 7/11/05 at 04:33 AM |
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quote:
Originally posted by DarrenW
What grade o poly bush are you using? I dont mean shore hardness here. Some poly bushes are meant more for undustrial machine antivibration purposes
more than automotive sportscar suspension. Some se7en types seem to suffer more than most. I rebuilt a Golf Gti a while ago using cheap bushes.
Supplied with red grease. They creaked to the point where they were extremely annoying and embarassing. So far my ZR hasnt creaked at all. They have a
special compound to prevent it and dont require any grease.
It's quite common to find PTFE as an additive in acetal products and graphite in a number of polymers including PU but I doubt if they would
entirely preventing squeaking if the bushes aren't coaxial (which is often the case with home made wishbones).
Squeaking can usually be attributed to three things:
1. Bushes being misaligned.
2. Not being lubricated properly.
3. "Interference" fit being too tight.
You intend driving around in a Locost and you're embarrassed by a mere squeak? 
There is some debate as to whether graphite impregnated PU is of any benefit as all the graphite particles are totally encapsulated by the resin. I
can see the logic behind that arguement, but only when applied to cast bushes.
If the bushes are machined from graphite impregnated PU rod or oversized tube, then the process of turning the bush bores will expose the graphite
particles. At least, that's my experience and they worked well.
[Edited on 7/11/05 by Rorty]
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
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Peteff
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| posted on 7/11/05 at 10:46 AM |
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You intend driving around in a Locost and you're embarrassed by a mere squeak?
Around 5 to 10mph my rear springs sound like an old mattress . It's just something else to grin about. I've greased the eyebolts and
WD'd everything occasionally but it seems to be a resonance thing so I try to keep a straight face when I go over bumps slow
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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